Why attend?

Everyone owes it to themselves and their business to gain knowledge and network with other people within the same industry. AERA understands that traveling to national trade shows to gain this knowledge and networking opportunities is very expensive. Therefore, AERA has decided to help by teaming up with a regional host and offer these opportunities to different regions of our country and hopefully closer to your shop.

Along with the outlined technical programs, AERA is inviting leading manufacturers of engine building/rebuilding tools, supplies, services, parts and machinery to attend these conferences. Suppliers will have table-top displays that will be accessible all day long. Meeting these suppliers in a relaxed atmosphere is a great way to begin lifelong relationships that will help you prosper.

FEBRUARY 25, 2012
Hosted by SUNNEN & MAHLE at Citrus Community College, Glendora, CA
Click here for the SUNNEN & MAHLE Attendee Brochure

APRIL 20, 2012
Hosted by JOE GIBBS RACING, Charlotte, NC

MAY 19, 2012
Hosted by LIBERTY, New England Warehouse, Worcester, MA

JULY 19, 2012
Hosted by EPWI, Denver, Co

SEPTEMBER 27-29, 2012
Hosted by ROTTLER (In conjunction with the Rottler open house) Seattle, WA

SEPTEMBER 28-29, 2012
Hosted by COMP CAMS, Memphis, TN

DECEMBER 6-8
Hosted by AERA (In conjunction with the IMIS TRADE SHOW), Indianapolis, IN

We will have more specifics coming your way via brochures, email, website and Engine Professional magazine in the coming weeks and months. Please mark these dates now and start making plans to attend a Tech & Skills Conference near you!

QUESTIONS? Call AERA toll-free 888-326-2372 or direct at 815-526-7600.

• FEBRUARY 25, 2012
  Hosted by SUNNEN & MAHLE at Citrus Community College, Glendora, CA
• APRIL 20, 2012
  Hosted by JOE GIBBS RACING, Charlotte, NC
• MAY 19, 2012
  Hosted by LIBERTY, New England Warehouse, Worchester, MA
• JULY 19, 2012
  Hosted by EPWI, Denver, Co
• SEPTEMBER 27-29, 2012
  Hosted by ROTTLER (In conjunction with the Rottler open house) Seattle, WA
• SEPTEMBER 28-29, 2012
  Hosted by COMP CAMS, Memphis, TN
• DECEMBER 6-8
  Hosted by AERA (In conjunction with the IMIS TRADE SHOW), Indianapolis, IN

AERA invites all suppliers to present their products and distribute literature on table-top displays at these one-day conferences. If you cannot attend, AERA will set-up your table-top display and be sure your literature is distributed. AERA associate members pay only $325 for one 6 ft. table. (Non AERA members pay $400.) Space is limited.

Click here for the 2012 Display Brochure and Registration Form

QUESTIONS? Call AERA toll-free 888-326-2372 or direct at 815-526-7600.

Intake and exhaust valves are available today in a staggering range of choices. In this article, we attempt to clarify and explain the differences, in terms of materials, their performance aspects, an overview of valve coatings and to provide a broad reference in terms of valve selection.

STELLITE

Stellite is a hard coating applied to valve stem tips and faces to provide a hard surface, to minimize wear. Stellite alloy is a non-magnetic and non-corrosive cobalt-chromium alloy that may also contain a tungsten element. It resists embrittlement and annealing at higher temperatures. Interestingly, the term Stellite was derived from the name of a Scottish racehorse (yeah, I know…who cares?). Stellite is often applied to steel or stainless steel valves.

SODIUM-FILLED

Sodium-filled valves feature stems that are precision-gun-drilled and filled with a specially formulated sodium. This achieves weight reduction (the result of the gun-drilling to create a hollow stem) and better heat dispersion. There is some debate concerning the efficiency of this heat transfer, due to concerns that the heat transfer to the guides increases guide wear. Even with these concerns in mind, it’s interesting to note that the Chevy LS7 engine features sodium-filled exhaust valves (along with titanium intake valves).

The hollow space in the head/stem of a sodium-cooled valve is filled to about 60% of its volume with metallic sodium, which melts at about 206 degrees F. The inertia forces that result during valve opening cause the liquid sodium to migrate upwards inside the stem, transferring heat to the valve guide and subsequently to the water jacket.

HOLLOW STEM

Hollow-stem stainless steel or titanium valves (no sodium-fill) features gun-drilled stems to create hollow stems, strictly for weight reduction (this reduces valve weight by approximately 10% as compared to a comparable solid-stem valve). Citing Ferrea as an example, their hollow stem valves are gun-drilled and micropolished, and feature friction welded tips, shot-peened and rolled lock grooves, “avionics” chrome plated stems, and feature face hardness up to 42 HRc. This micropolishing reduces the risk of stress risers in the I.D. walls of the stem.

STAINLESS STEEL

Although stainless steel valves may be offered in varying grades/alloy recipes, high performance stainless steel valves are most commonly made of material referred to as EV8 (a more expensive heavy-duty stainless alloy material), and are made from a one-piece forging. In addition, some valve makers offer a stronger stainless steel formula that offers higher heat resistance (Manley’s XH-428 is an example). Some makers use EV8 only for their exhaust valves, while others utilize this material for both intake and exhaust valves. High quality performance stainless valves should feature hard stellite tips (since stainless is not hardenable, a hardened tip must be welded onto the stem) and hard chrome plated stems (not cheap flash chroming) to reduce guide wear. Undercut stems contribute to slight weight reduction and benefit flow characteristics. Note: if a particular brand of stainless steel valves does not feature a hard tip, the use of lash caps will be required.

TITANIUM

Titanium (chemical symbol Ti) offers the highest strength-to-weight ratio of any known metal. In an un-alloyed condition, Ti is as strong as some steel materials but about 45% lighter. When used to manufacture automotive valves, titanium is alloyed with small percentages of various materials, including copper and molybdenum. Titanium is a fairly hard material and can be challenging to machine, as it can gall if tooling isn’t hard and sharp enough, and if the material isn’t cooled properly during machining.

Just for the sake of trivia info, titanium was actually discovered independently by a couple of guys including a British amateur geologist and a German chemist in the late 1700s. The German, Martin Heinrich Klaproth, reportedly named the material titanium for the Titans of Greek mythology. Pretty cool. Maybe this dude was a racer at heart without even knowing it. Eventually, starting in the 1950s, titanium began to see serious use by both the U.S. and the Soviet Union for military applications including submarines and jet aircraft.

Many titanium valves are generally produced by starting with a forging, then machined to final shape, but some are produced using a two-piece inertia-welded design. Citing Xceldyne as an example of this approach, they utilize an inertia welding process to attach a partially machined valve head and stem together. During this process, the two previously machined parts are fused together using state-of-the-art equipment that uses inertia and a force to weld the two pieces into one solid component. Once the valve blank is welded, it’s heat treated to alter the grain structure of the titanium through precision heating and cooling at varying temperatures, taking into account the properties of the alloys and the specific application (intake or exhaust). According to Xceldyne, this process is so effective that inertia welded valves have been certified as having a superior grain structure as compared to a one-piece forged design. The valve is then CNC machined and in many cases undercut in the stem area to allow a bed for the inlay of a coating. The valve is then plasma moly coated. Specific sections of the valve are further machined and the stem is ground, leaving the plasma moly coating over only the desired stem area. The head, stem and keeper grooves are then final machined. Stem grinding is then finalized to establish dimensional tolerance to within 0.0002”. The valve is then precision polished to reduce the potential for carbon buildup.

Various styles of valve tips are generally available, which includes a hardened steel tip, a diamond-like coating or a ceramic-coated tip (ceramic tips are to be used in conjunction with lash caps) and thin-film technology such as a PVD coating.

As we noted earlier, titanium is a relatively soft material, requiring a protective contact surface at the stem tips, usually requiring hardened lash caps. Xceldyne noted that when valves feature stem diameters smaller than 5/16” (7mm or less in diameter), a specialized hard coating is applied to the stem tip in order to protect the tip from lash cap friction.

The ceramic coating is a durable hard coating intended to protect the titanium from the friction caused by the lash cap. Other coatings such as a PVD (plasma vapor deposition) treatment, a CrN (chrome nitride) treatment, CVD (chemical vapor deposition) or DLC (diamond-like carbon) or other highly specialized protective applications may be applied to the tips. This hardened feature at the tip prevents material transfer or galling between the tip and lash cap.

Hollow titanium valves are also available, either with hollow stems or with a combination of hollow stems and hollow heads. Hollow stem designs reduce valve weight by about 10%. The hollow head design is a proprietary process that removes an additional 6 to 8 grams of weight (of course, depending on valve size). As part of the proprietary process, the inside of the valve head may be reinforced to provide a support structure for strength and rigidity.

When a stem is gundrilled, according to Xceldyne’s Scott Highland, careful attention is paid to achieving a consistent precision surface finish and concentricity in the I.D. to obtain uniform stem wall thickness. Sonic measurement technology (and other proprietary methods) are employed to monitor the I.D. operations.

Scott noted that the commonly used lock design for titanium valves is the “super 7” style, commonly referred to as a 7-degree lock, which is actually closer to 8 degrees. Lock grooves are square grooved or radiused for superior lock engagement as well as reduced potential for stress risers. Xceldyne notes that they apply a specialized thin-film PVD coating to the locks and retainers to prevent material galling between titanium/titanium materials. Scott mentioned that lock-to-retainer interface is perhaps the biggest galling-potential issue that must be addressed.

Scott also noted that while undercutting is employed on many titanium valve designs, there are occasions where exhaust valves may feature an overcut in order to provide the required additional cross-sectional mass needed for some extreme applications.

Precautions concerning the handling and use of titanium valves

• Do not touch the valve surface with your bare hands, since fingerprint acids may affect the coating). Use gloves or coat the valve with oil before handling.

• Never use a lapping compound, or any abrasive material when the valve is coated with a PVD style coating.

• Valve seats should be replaced during each and every rebuild in order to insure a proper valve-to-seat contact. The width of the contact zone (valve face to valve seat) should be at least 1mm.

• New valve seats should be a relatively soft material, such as bronze or nodular iron (heat treated to Rockwell RC32 or less).

• Unless directed otherwise by the valve maker, always use hardened lash caps on titanium valves. Some makers offer valves built with friction-welded hardened tips. Bare, unprotected titanium tips are relatively soft and will mushroom when exposed to rocker arm forces.

If a titanium valve features a stellite tip (hardened stellite tipped valves don’t require lash caps), during valve service, the stellite tips can be ground, but with caution. You should be able to safely remove approximately a maximum of 0.015” to 0.020”. It is absolutely essential that you check with the valve maker to determine if the tip is hardened or not, and if hard lash caps are required or not! Don’t assume anything…. If you run without lash caps when they’re required, you’ll ruin the valves in a heartbeat.

As far as valve seats are concerned, again keep in mind that titanium is a relatively soft material. A traditional cast or hard seat can beat a groove into the valve face, so a nickel bronze seat material is recommended.

Del West, for example, now offers a titanium valve that features a steel tip so no lash cap is needed, and the rest of the valve is coated with chromium nitride, making it compatible with ductile iron seats or beryllium-copper seats.

KPMI (Kibblewhite Precision Machining Inc.), to cite an example, recommends the use of their Ampco 45 seat material for titanium valve applications. This material’s high 80% copper content provides excellent thermal qualities, and the 5% nickel provides just enough hardness to prevent pounding-out. The remaining aluminum content provides the degree of softness to prevent damage to the titanium valve face.

Titanium valves are extremely lightweight and are designed for applications where valvetrain weight needs to be reduced, for high-rpm and extended high-rpm applications, since titanium valves allow for higher engine speeds and will accommodate highly-aggressive camshaft profiles. The lighter weight contributes to minimized wear on rocker arms and improved valve spring life. As valve weight is reduced, lighter springs can be used. As spring force is reduced, this reduces frictional loads between the lifters and cam lobes. So, the use of titanium valves offer both higher engines speeds, quicker engine acceleration, and reduced friction throughout the valvetrain. While lighter weight and the resulting ability to achieve higher engine speed is of obvious benefit in any form of racing, the ability of the engine to produce quicker acceleration is extremely beneficial in a drag racing application.

It should be obvious that titanium valves are designed for higher engine speeds, which is fine for higher top-end power. However, for extreme temperature situations (blown, turbo, nitro engines), titanium may not be the ideal choice. Also, for many street applications, titanium may not be a good choice for an engine that doesn’t need to rev as highly, and for an engine that will be buttoned up and not torn down and serviced regularly. In other words, it’s probably best to reserve the use of titanium for naturally-aspirated race or inlet-side forced induction applications where valvetrain weight and sustained high-rpm use is paramount.

The Del West engineers sum-up the benefits of lighter valves succinctly: Creating a broad power band of lower-RPM power for the run off-the-corner has the greatest impact on lap times, and represents the largest challenge to engine builders.

However, whether the goal is maximum peak power or the broadest possible torque curve, titanium valves and other lightweight valve train components give the engine builder greater freedom in choosing camshaft profiles. The lighter mass also promotes faster valve acceleration from any RPM, again giving the engine builder and cam designer more flexibility. The additional benefits of lighter valves, retainers and locks is that they can push valve float to levels of RPM above which you intend to operate the engine.

NIMONIC 90

Nimonic is a nickel-chromium alloy. A specific grade of this material, Nimonic 90, is used by some makers for producing high performance valves. Nimonic 90 is a “super” alloy comprised of nickel-chromium-cobalt, which offers high strength and especially an ability to withstand extremely high temperatures, reportedly well within the 2000 degree F range, without distortion. This material is also widely used in aerospace industries for applications such as valves in turbo motors and blades and discs in gas turbines. Manley reports that they’ve seen success in such extreme applications as nitromethane and high-boost turbo applications such as multiple-turbo tractor-pull engines.

INCONEL

Inconel is a registered trademark of Special Metals Corporation, referring to a family of nickel-based superalloys. Inconel alloys are oxidation and corrosion resistant materials designed for use in high heat environments. Inconel retains strength over a wide temperature range. As opposed to steel or aluminum, Inconel doesn’t creep as much (change dimension) under high heat use. Inconel is commonly used in high stress aircraft applications such as high-speed airframe and jet engine components.

Five “grades” of Inconel are in common use, including 600, 625, 690, 718 and 939. As an interesting sidenote, a special Inconel X material was used in the makeup of the skin for the legendary X-15 rocket plane.

Basically, the benefits of Inconel include light weight, extreme resistance to temperature, high strength and resistance to thermal dynamics.

Inconel alloy makeup (depending on the specific alloy mix) can include carbon, manganese, silicon, phosphorous, sulfer, nickel, cobalt, chromium, iron, aluminum, molybdenum, titanium, boron and copper, with the heaviest material concentration accounted for with nickel and chromium.

Inconel valves offer extremely high thermal resistance and are designed for high heat applications as found in turbocharged, supercharged and nitrous applications.

Reducing Valve Mass: A Camshaft Maker’s Point Of View

Since valve weight in particular naturally relates to valve spring force and cam profile selection for given race applications, I contacted the folks at Comp Cams for their input.

For the majority of street engines, a quality stainless steel valve is recommended. Billy Godbold of Comp cams noted that they prefer titanium for most race applications, but that some engine builders that specialize in turbocharged applications prefer a high nickel Inconel valve. “We have to leave the final decision up to the engine builder, but it does limit the cam designs we can choose from when going to a heavy valve.”

Hollow stem valves tend to work great on the intake side, but they are much more difficult to manufacture and to inspect for defects on the I.D. surface. Many of the upper-echelon engine builders shy away from hollow valves for that reason in endurance (NASCAR or 24-hour style) racing.

Comp’s Thomas Griffin noted that stainless steel valves are most common in street and mild-performance racing. Titanium is used when valve weight is important and when budget is not a consideration. Inconel is used when exhaust gas temps get really high. Stainless steel (for street performance) has much better durability characteristics than titanium, and the street guys won’t usually see the real benefits of titanium. In racing, use titanium when you want to lose weight and spend a lot of money. Of durability is a concern, and you’re already making as much power as you want and are already turning the engine as high as you want, then you need to use a stainless steel material. If you’re running nitromethane, then an inconel exhaust valve material will be your best bet if you want to finish a race. NASCAR engines use a variety of titanium materials because of the temperature and impact related issues associated with their severe applications.

Godbold noted, “On the exhaust side, sodium-filling is the best way to increase the head capacity of a hollow exhaust valve. If stock diameter steel valves are required, but a valve weight is not mandated, going to a hollow intake and sodium filled exhaust is certainly a major advantage.

“From our point of view,” Godbold continued, “the most critical point is to get mass out of the valve. The lighter the valve, the stiffer the valvetrain system is in relation to the mass it must move. Also, as the valve mass is decreased, you can reduce the spring force needed to control a given valve motion and/or go to a more aggressive cam design that can make more power.”

To prevent excessive tip wear on titanium valves (especially the small O.D. non-hardened tip variety), using a lash cap provides an excellent wear surface for the roller tip, sliding contact or cam follower. While you always want the rocker to push down on the section of the cap directly over the stem, using a lash cap certainly gives you a better sense of safety as you approach the edge of the valve in high lift applications with a very small (5 to 7mm) stem.

Griffin noted that since engine builders and cam designers push limits, the stems get smaller and the lift gets higher. As a result, lash caps are used with smaller valves to better distribute the load across a larger area than the base stem tip area. They are also used with higher lift because when the lift is increased, the rocker arm sweep length usually increases across the valve or lash cap as well, compounding the issues caused by the smaller valve stem diameter.

We only provide solid stem designs through Comp Cams, but the hollow stems certainly provide lower mass. Theoretically, these would be the best way to go, but there are very serious manufacturing and inspection hurdles to jump when producing a hollow valve.

The question becomes “where is the safest and best way to invest my money when building this engine for this specific application and within this budget? Sometimes your answer will be a hollow valve, but in most cases it would probably be a solid valve stem unless we see a major technical jump on the manufacturing side. As the OEMs start pursuing that route on the mass market side, we could find new technologies available to make these parts on the performance and racing side. We have certainly seen that effect with the availability of several new Beehive valve springs and now nitrided flat tappet cams that we offer. Just a few years ago, we could not provide either of those technologies dependably, at a high level, and for a reasonable cost, but lower machine cost (although the cheapest machine was still on the order of a quarter-million dollars plus) for the tools to manufacture these parts became available in recent years.

Per Griffin, solid stems are stronger, hollow stems are obviously lighter, but the quality control of an inside stem surface is very difficult to control. Because of the pounding of the valve upon closing, the sensitivity to failure is compounded if there are machining marks that can neither be controlled nor removed because they cannot be seen.

While 95% of our market uses a square groove lock, the stresses in the valve are minimized with a single round groove. The lowest stress system is a top lock design with a small round groove at the top of the lock, and the lock is designed with a slightly smaller angle than the retainer so that the valve is held by the collet force squeezing more at the bottom region of the lock-to-valve interface.

“Round grooves are best because they address the issue of stress concentration zones associated with a very small radius of the inside corner of a square groove lock. In high-end racing with any material valves, retainers and locks,” Griffin stated, “I would use only a single groove because it forces the lock to grip the valve stem and hold it in place.” Many OEM engines feature multiple-groove steel locks and valves that allow the valve to spin in the locks, which is fine for street and low-end performance. Because there is a loose fit between the valve and locks, it could cause an over-stress condition if used in severe racing.

Godbold noted that “because Comp Cams only offers a street valve, we tend to defer many of these questions to the experts at the valve engineering and manufacturing end. We have worked very closely with Del West and Xceldyne on projects in the past and will continue to do so in the future.”

The Bottom Line

As a quick summary, high quality EV8 stainless steel valves are a good choice for street and naturally-aspirated race engines, while titanium valves accommodate high engine speeds in race engines that don’t experience uncommon extremes in temperatures, and Inconel (and other similar nickel content) valves are suggested for extreme cylinder pressure/extreme temperature applications (primarily exhaust). For extreme-temperature applications such as very high cylinder pressure nitromethane, blown or supercharged use, a combination of titanium intake valves and Inconel or Nimonic exhaust valves are appropriate.

Valve Coatings: More Than Meets The Eye

Instead of simply listing the names for the various valve coatings, we wanted to provide a bit of information about each of these specialized coatings. The information that follows was provided courtesy of Del West Engineering and Xceldyne.

• PVD (Physical Vapor Deposition) occurs because of a physical reaction. Inside a vacuum chamber plasma environment, metals are deposited via evaporation, sputtering or arcing fragments of the metals which are physically moved on to the substrate. In other words, there is no chemical reaction which forms the coating on the substrate.

• CVD (Chemical Vapor Deposition) occurs because of a chemical reaction. The process exploits the creation of solid materials directly from chemical reactions in gas and/or liquid compositions or with the substrate material. The product of that reaction is a coating material which condenses on all surfaces of the part to be coated and inside the vacuum chamber plasma environment.

• DLC (Diamond Like Carbon) coating is a thin-film coating applied via a plasma-assisted Chemical Vapor Deposition (PaCVD) process. This coating combines very low frictional resistance and extreme hardness. The coatings are used to reduce wear and friction for rapidly-reciprocating components, where friction reduction is a primary goal. Common applications include finger followers, tappets and piston pins.

• CrN (Chromium Nitride) is a thin-film coating also applied using a PVD process. According to Del West, a cathodic arc is discharged at the target to evaporate the chromium into a highly ionized vapor, which is done in a partial pressure of nitrogen. This provides a higher level of adhesion as opposed to a PVD sputtering method in which a glow plasma discharge bombards the material and sputters some material away as a vapor. Del West commonly uses this process for titanium, steel and nickel-based valves.

Thermally-sprayed coatings can provide thick coatings over a large area at high deposition rate as compared to other coating processes such as PVD or PaCVD. These are coatings that include plasma spraying and High Velocity Oxygen Fuel (HVOF) spraying that are widely used to protect valve stems and tips.

Thin-film coating options such as CrN (Chrome Nitride), TiAlCrN (Titanium Aluminum Chrome Nitride), DLC (Diamond-Like Carbon) and a:SiC (Amorphous Silicon Carbide) are selected during the valve design process based on the suitability of the coating properties for the specific engine application and with reference to historical post-engine teardown feedback and analysis.

In certain applications, a combination of coatings may be selected for an individual valve.

For example, the “ductile” properties of a CrN coating (Hardness 1,600 HV) will be selected for application to the valve tip, while the “low friction” attributes of a DLC or a:SiC coating (Friction coefficients 0.1 or less) will be chosen for application to the critical valve seat head region.

Dry fuels such as those with low-sulphur content or alcohol based are suitable environments for certain low-friction and inert thin-film coatings. The application of a coating upon the valve head and valve stem can be exploited as a “solid lubricant” minimizing adhesive wear between the valve-seat or valve-guide interface. Adhesive wear, also known as scoring, galling, or worse case seizing, results when two solid surfaces slide over one another under pressure. Surface projections, or asperities, plastically deform and eventually weld together under the high localized pressure. As sliding continues, these bonds break. This creates cavities on one surface and projections on the other. Tiny abrasive particles can also form causing additional wear.

Specific to applications associated with excessive exhaust gas temperature, hybrid coatings (Pt, Pd, Nb based) have been examined as a means to retard embrittlement of the base Ti material by minimizing the ingress of oxygen through the coating and represent novel strategies to yield robust coatings for ultra-high  temperature environment applications.

—

Mike Mavrigian has written thousands of technical articles over the past 30 years for a variety of automotive publications. In addition, Mike has written many books for HP Books. Contact him at Birchwood Automotive Group, Creston, OH. Call (330) 435-6347 or e-mail: Mike@birchwoodautomotive.com. Website: www.birchwoodautomotive.com

For a PDF of this article (complete with photos), go to:
http://www.aera.org/ep/EPQ4-2011/index.html

Some of the best competition valve train specialists to emerge in the past thirty years owes much of its supremacy to extensive developing and testing of its competition parts. The test machine is a SpinTron. Parts tested are principally roller tappets and rocker arms.

“Ten or twelve years ago when I first pressed the SpinTron into action,” says Danny Jesel, “my immediate response was one of shock—the racket it generated was incredible! I just wasn’t expecting the opening and closing of two valves to be so loud, and initially I thought something was broken.”

Once Danny Jesel became accustomed to the commotion, his next challenge was grappling with the phenomenon known as lofting. Lofting occurs when engine speeds increase, usually above 4,000 rpm, causing the tappet and valve train components to lose contact with the camshaft each revolution. As a result the valves remain open much longer than camshaft designers had intended. Some race engine developers call it “controlled valve float.”

“I was intrigued,” admitted Danny, “as I observed the valve gear components soaring over the nose of the camshaft by a distance greater than .100in above the lobe. It fascinated me, and I initially thought this thing called lofting will create havoc in the shortest period of time. But it didn’t. As I watched the SpinTron tracing the valve events, it became intriguingly predictable. I began to think of it as a ball connected to a bat by an elastic cord, and if you smack the ball with the same force each time, its travel through space will repeat.”

Although Jesel, a manufacturer, acquired their SpinTrons to test the durability of their valve train parts, most of these remarkable test machines are in the hands of the country’s leading engine builders. To stay ahead of their rivals, engine builders and professional race teams use them to gain vital data. Whether they are gathering information on valve train performance or calculating frictional losses within the engine, transmission, or final drive, they are aware that knowledge is power, and having access to SpinTron data is a good first step. “How else can you explore beyond normal mechanical limits of race engine development without provoking a trail of devastation,” says SpinTron creator Bob Fox.

Cause and Effect: The Study of Valve Response to Cam Lobe Motion

Advanced engine development, either for the race track or at the OE level, depends on the ability to test and simulate real-world conditions while in the laboratory. Only in a controlled and repeatable environment can accurate data be gleaned. Certain areas however, such as the study of the valve train while it operates at high engine speeds, have denied close examination until fairly recently. SpinTron changed all of that—the behavior of every component responsible for valve actuation (either OHV or OHC) can now be examined, imaged, and graphed in real time for analysis.

The SpinTron was born of necessity by Trend Performance’s owner and founder Bob Fox. Being desirous of creating the ultimate push rod for racing applications, there seemed no way to improve its design other than hit-and-miss dyno testing. And when pushrod failure did occur, the reason was often unknown. For valve train technology to move forward, Fox recognized that a means to study the valve’s response to the profile of the camshaft was necessary. The SpinTron quickly revealed what was believed to be happening in the valve train was not the case. The proverbial book on valve train dynamics needed to be completely rewritten, and the SpinTron would be the author.

Armed with a cost-effective device that obtains accurate valve train analysis, racing teams and engine builders along with original equipment manufacturers began to embrace the SpinTron. There was a collective response within the industry, particularly within Nascar circles, for the virtues of this test fixture. But despite the progress it pioneered in the past fifteen years, many engine builders are still unfamiliar with its workings and benefits—benefits available to engine development programs at any level. For this reason Engine Professional magazine prepared this primer establishing the basic function, design, and operation of the SpinTron.

The Components

At first glance the SpinTron resembles an engine dyno. There is, however, one huge difference—where the water brake would reside there is a large electric motor concealed in the apparatus’s sheet metal housing. Instead of the engine working against a brake, the electric motor spins the crankshaft which in turn runs the engine without fuel, ignition, or combustion.  The data acquired during the test procedures is processed and stored in the SpinTron’s computer.

When the test engine is mounted on the Spintron it is fitted with a mandrel (dummy crankshaft) and a lubrication system. The lubricating system can be either of SpinTron origin or alternately of a conventional dry-sump arrangement, as depicted in this story.

There are two principal versions of the SpinTron: a gear-reduction model and a direct-drive model. The gear-reduction model, which is the most prevalent, is used principally for valve train testing and is offered with one of four electric motors: 25, 50, 75, or 100 horsepower. On the other hand the direct-drive model is equipped with a 150-, 200-, or 250-horsepower motor. It is used for spinning the entire engine, including pistons, and its principal function is to determine frictional loses. With an optional torque arm attachment this more powerful machine has the capacity to measure torsional deficiencies of internal components. The gear-reduction machine operates up to 11,000 rpm whereas the direct-drive model, which uses liquid-cooled electric motors, operates up to 12,000 rpm.

Regardless of the model of SpinTron, valve train analysis can be performed as a function of a Laser Valve Tracking System (LVTS) or, alternatively, through a very high-speed camera that captures up to 4,000 frames per second. The LVTS provides measurable data, for example, data displayed on a graph showing the magnitude and duration of valve openings referenced to the crankshaft position. The high-speed camera allows valve events to be viewed but not measured.

In addition there is an optional high-speed data acquisition system boasting 16 differential 16-bit analog inputs, 250 KHz acquisition rate, 2 pulsed inputs of up to 5 MHz and 2 encoder inputs. The 16-bit analog input option relates to the number of sensor signals the machine’s high-speed data acquisition system can receive. For example, you might wish to monitor a load gauge under a valve spring or, perhaps, observe the differential signal of an oil temperature sensor. This high-speed optional acquisition system converts the differential signal to an intelligible gauge reading. The term 250 KHz reveals how fast the Spintron receives and stores its information. The encoder is used to identify the position of the crankshaft, and the two pulsed inputs permit the use of two encoders which, for example, could be used to determine torsional deficiencies in a part.

Other functions such as a 16-digital I/O (input/output) signal, a termination board and oscilloscope can be added. The oscilloscope allows valve motion to be observed in real time. Additional sensors to measure flow, pressure, vacuum, temperature, and knock can also be integrated into the SpinTron. Accordingly, any or all of this data can be acquired during testing and, importantly, recorded on a report. A work station console is offered as an option or the operator can choose to run the SpinTron though a laptop or PC with the dedicated software. For endurance testing, other custom accessories can be ordered for your engine program.

Testing

The most common use of the SpinTron is testing with the LVTS. To perform this task a window is cut into the engine block and the laser head is inserted in the cylinder bore facing upward at the head of the valve. The results of the valve’s behavior will then be displayed on a graph referenced to the crankshaft position.

The common custom for using the LVTS is to first create a baseline of the valve’s action at a low rpm, when the valve’s opening and closing events will repeat precisely the profile of the cam lobe. Baselines are typically established at 2,000 to 3,000 rpm. Then, through the control software, engine speeds are increased in increments of your choosing. The SpinTron will record each new valve trace over the baseline trace. This practice, known as step-testing, performs complete valve train analysis, providing the ideal conditions to compare valve train stability at different engine speeds. It detects events such as valve bounce; lofting (that is, when components of the valve train lose contact with each other due to inertia); harmful spring harmonics; and pushrod deflection. It also identifies weaknesses, design flaws, and misbehavior that will not only cost horsepower but reliability as well.

Another important area of research is endurance-testing or cycle-testing where every gear change and every rpm over the duration of a race or over thousands of road miles can be simulated. In common with step-testing, the SpinTron can record and graph data from a variety of sensors at different engine speeds. This provides an excellent opportunity to test a host of components like a fuel pump or an oil pump, as it will record vacuum or flow or pressure during each segment of a lap. Running comparison tests is also effective, particularly comparing different valve springs.

Through advanced software, dedicated race track simulation can be created without the risk of engine wear or failure and without any fuel or vehicle required. None of these components are needed to perform SpinTron testing.

Seeing is Believing

To gain practical exposure to the SpinTron, Engine Professional magazine traveled to Lakewood, New Jersey, and visited the facility of Jesel Valve Train. There we met Walter Donovan, a humble man with exemplary credentials, who provided us with a demonstration of the SpinTron. Walter is an accompanied engineer, a metallurgist and scientist, and one of the individuals responsible for Jesel’s leadership in valve actuation and dynamics.

Jesel employs two gear-drive Spintrons, each located in a dedicated cell.  Both machines are constantly in use for R&D testing. It is admittedly the one tool that has allowed Jesel to revolutionize the valve train of the pushrod competition engine.

When queried about the SpinTron Walter Donovan was quick to state, “Without such a tool the speed of our development programs would have been hampered and our knowledge, particularly of modern valve spring development, would have been severely impeded.” He further stated, “Cylinder head development is a moving target, and to get the most from any improvements in volumetric efficiency, the valve train needs to work properly, and at higher engine speeds. During our early days of testing at Jesel, we were shocked by the dramatic effects of minute changes to the cam or rocker profiles and the impact they had on the valve action and, as a result, on horsepower and rpm capabilities.”

After a morning of working with the SpinTron, it is the author’s opinion that a valve train not developed using this equipment is leaving potential gains on the table, and if it works, it is only by chance and not by sound engineering.

As race and OE engines continually push the technological envelope for different goals, practical valve train analysis becomes essential in that process. Is the SpinTron for everyone? No. It is only for those that want their engine program to be the best. The others must try to follow.n

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Editor’s Note: After discussing SpinTron virtues and limitations with at least one NASCAR team, it was agreed that Spin Tron is a state-of-the-art test and R&D tool capable of generating solid, reliable data for variables it can control. What SpinTron cannot do is test all variables at one time normally experienced on the race track, especially those races lasting 500 miles or longer in the case of endurance road races.

About the Author

Ray T. Bohacz’s interests have always revolved around mechanical apparatus but he admits his true love is engines. It matters little if it is a Detroit Diesel-powered irrigation pump in the middle of a corn field or nitro-burning Hemi. His first byline appeared in 1995 and has since published over 1,200 in-depth technical articles pertaining to engines. He has also authored three books on engine systems. He is a member of SAE, American Society of Materials and the International Motor Press Association.

For a PDF of this article (complete with photos), go to:
http://www.aera.org/ep/EPQ4-2011/index.html

Given the choices, why would one use a copper head gasket? Let’s dig into it because there are applications (perhaps more than you think) for which copper head gaskets are the best choice. To be sure, copper has been around for a while and with good reason. Let’s walk through some of the attributes and benefits unique to copper, then we’ll get ready to put them on.

Malleable: Copper is stronger than any composite head gasket yet still malleable so it conforms to the sealing surfaces. This strength-malleability combination is, more than any other attribute, the ‘selling point’ of copper as a head gasket material over other materials. While the advantages of strength are self evident, the benefits of a malleable gasket body are somewhat more nuanced. Simply put; conformity makes a tighter seal which will show up in lower leak down percentages.

Metal-to-Metal: To an engine builder, the words “High Performance” pre-suppose high pressure, high pressure requires a more robust combustion seal and the best combustion seal is metal-to-metal. I’ll elaborate; many cylinder head gaskets are coated with sealants designed to eliminate fluid leaks. From experience, readers of this article will be familiar with the various types from slick to sticky and while these work well for fluid sealing they are not able to withstand combustion pressure and heat. No matter how good an elastomeric coating may be for coolant or oil, it will eventually scrub off, burn off, or blow off the fire ring area of the head gasket and in performance engines this can happen in a surprisingly short period of time. Once the sealant is gone from the fire ring combustion seal, it’s a short trip to the nearest coolant passage. Silicone, or other rubber-like sealants or coatings should never be placed on the combustion seal in performance engines.

Options: Copper comes in a wide range of thickness choices; (from .021” to .093” in roughly ten thousandths increments) providing the options necessary to optimize piston to valve, piston to head and, in wedge combustion chambers, piston to quench area.

Conductivity: Copper is the standard for conductors; in head gaskets we don’t care about electricity but we do deal with heat. Superior conductivity benefits performance and racing engine builders in two primary ways: A. block & head temperatures are more even. B. Combustion chamber hot spots are dissipated quickly. Cylinder block/head temperature parity is an aid to tuning, though frankly, it’s a minimal factor until you reach the narrow end of the tuning window. The big advantage of conductivity is in the combustion chamber area. In and around the combustion chamber standard composite head gaskets and MLS head gaskets are somewhat insulated from the cylinder head and block by the facings and coatings respectively. Heat related failures occur more often with composite and MLS head gaskets than with copper because the heat is trapped within the gasket body allowing hot spots to intensify, whereas the copper being both a better conductor and having direct contact with the block and head (remember metal-to-metal) transfers the heat to the heat exchanger, aka the cooling system, through the head and block.

Elasticity: Another interesting feature of copper, this benefit comes into play when you’re out of the tuning window far enough to actually damage the head gasket. Un-alloyed or pure copper has a 25% coefficient of elasticity; cool term, here’s what it means. In a 4 inch section, the copper head gasket will stretch to 5 inches before it ruptures. This gives the user a ‘safety factor’ not available with other head gasket materials. Blown, nitrous or turbocharged engines can develop cylinder pressures high enough to lift the cylinder head or push the gasket. A typical bad-actor in this regard is the small block Ford; get some good cylinder heads, add some boost or nitrous, she’s goin’ fast but Daddy wants more and.. the head gasket is peekin’ out between the bolts. If this happens with copper the damage is apparent but the head gasket hasn’t yet failed. The safety factor of elasticity allowed the copper gasket to push but still remain intact so you can either back it down & make the next round or back it down & drive home. If you push a composite gasket, game over.

Do Copper Head Gaskets Require Different Torque Values? Generally No. Fastener torque values are determined in relationship with the cylinder head and block structure. Arbitrarily increasing torque values will distort the block or head. However, there are good cases for fine tuning the torque values based upon how the head gaskets look after the first use. A nice thing about copper head gaskets is that you can ‘read’ them very easily once you know what to look for and, what to look for is evenly distributed clamp load. No gasket works in isolation, all gaskets require clamp load to do what they do and copper gaskets tell you where the clamp load is light by keeping their shine. Specifically, you want to see machining marks from the block & head surfaces transferred to the copper gasket body everywhere on the gasket. Places where the original finish of the gasket remains need some attention. Keep in mind there may be other factors in play such as, a ring dowel counterbore that has become too shallow from surfacing or a head nut bottoming on the threads of a head stud. Once you have eliminated any mechanical obstruction preventing the head from seating properly, you can safely increase torque values in the light load areas by 5 to 10 ft lbs.

What about re-torquing? Solid copper (like a liquid) does not compress, it displaces. Since the copper gasket body does not compress, no re-torque is technically necessary. However, since the engine build using a copper head gasket is almost always within the realm of performance or racing, I always recommend one re-torque of the head bolts after a complete heat cycle.

Block and Head Preparation for Copper Head Gaskets: Cleanliness is next to..You might be surprised at some of the samples we’ve received from customers asking “why did it fail?” Then again if you’ve been around for a while, you may not be surprised at all. I have seen head gaskets with sawdust, sand and actual small rocks embedded in them, as well as the remains of facing material from the previous head gasket. The aircraft industry has an acronym that’s suitable here; FOD, Foreign Object Damage. Like leaving a wrench in the lifter valley, rocks in the combustion seal are not ok, chaos will ensue. So, as Momma taught us: let’s be clean when we’re doin’ our duty. Use a residue-free solvent such as aerosol brake cleaner and a clean rag on the head and block sealing surfaces before assembly.

Flat: Of course the block and head should be flat within .002” across and .004” lengthwise, with surface finish of 60 to 80RA preferred, 60 to 100RA acceptable.

Combustion Sealing: Head gasket sealing is a matter of balance and more pressure is needed on the combustion seal than other areas of the gasket. This is due to the vast difference in pressures acting against the head gasket. Consider that an engine developing 1.5 to 2 horsepower per cubic inch will have between 1000 and 1200 psi in the combustion chamber while, less than 1/2” away, the cooling system is running at 22psi max. Since a standard copper gasket is flat, clamp load from the tightened head bolts will be distributed evenly unless some method is used to ‘tip the balance’ and concentrate the proper load on the combustion sealing area. When using flat copper head gaskets, the accepted method has been to install O-rings in the block or head sealing surface around the bore or chamber respectively, to accept an o-ring. What’s an o-ring you ask? Simpler than you think, it’s just a piece of wire tapped into a groove that sticks out enough to pinch the copper gasket. Well, maybe that’s an over simplification but all you have to know from there are the proper dimensions of the O-ring groove.

Sealants Required? Yes, some method of sealing is required if the engine will be running coolant or oil through the head gasket. I state it this way because many racing specific engines either A. do not run coolant or B. re-route the coolant and oil away from the head/block mating surfaces. Since most engines run coolant and oil through the head gaskets we’ll discuss head gasket sealants. Most importantly, you don’t need very much; second, don’t use silicone.. that about covers it. People get into trouble with leaking head gaskets when they use too much sealant, especially too much silicone. Since the block and head surfaces are flat, the potential leak paths are very small, even with a 100RA surface finish the peaks and valleys are only about .002”, which doesn’t require very much sealant to be fluid-tight. Head gasket dressings do not cure, therefore, as the head bolts are tightened the sealant ‘flows’ from the places it’s not needed (peaks) but remains in place to seal the leak paths (valleys). By contrast, silicone cures to form a layer that the cylinder head can sit on, never actually coming into contact with the head gasket (refer back to our discussion about metal-to-metal above). We recommend and use both KW Copper Coat and Hylomar in the aerosol cans, simply spray a light coat on both sides of the gasket, let it ‘tack up’ for a while (no less than 2 hours) and you’re ready to bolt the heads on.

We could go into much more detail about each of these items if this was a technical manual, but my hope is that this information will be of help to you when the need arises, or you need some options that are not available from conventional head gaskets.

SCE Gaskets manufactures a complete line of racing and performance gaskets including standard flat copper head gaskets of the type discussed here.  As well, we offer our patented self sealing (no sealant required) copper head gaskets for use with O-rings and self sealing copper head gaskets with Integral Combustion Seal O-rings (no machining required). We also have a complete line of replacement gaskets for passenger cars, light trucks, vintage and tractor engines marketed under our Engine Master brand.

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Ryan Hunter is the founder and President of SCE Gaskets, Inc., a U.S. manufacturer of engine gaskets, from racing to replacement, with plants in California and Iowa. A self described “gearhead,” he began his career in the industry as a parts counterman then made his income as a mechanic and engine builder. During his 22 years at the helm of SCE Gaskets, several of Ryan’s gasket inventions have been awarded utility patents and he has more patents pending. His interests are family, business and anything with an internal combustion engine. For more information, please contact him at 661-728-9200.

For a PDF of this article (complete with photos), go to:
http://www.aera.org/ep/EPQ4-2011/index.html

Engine builders and rebuilders, especially in low and medium volume flexible production environment, strive to at least match (or surpass) the OEM surface finish and size specifications when it comes to honing bores of various engine components such as cylinder block, liners, connecting rod, cam bore, crank bore, etc.

Given the higher volumes, OEM’s dedicate equipment that is customized for the part. For example most Automotive OEM’s use a single pass honing (also called diamond sizing) when finishing connecting rods.  Lately some of them have been using a combination of single pass honing and conventional honing to meet certain engineered surface characteristics. Cylinder block and liners on the other hand are honed by traditional stroke honing techniques, while the crank bore is single pass honed to get final hole alignment and fine finish with high bearing area ratio. Even in conventional honing, OEM’s are also implementing technologies such as Helical Slide Honing developed by Nagel, which has shown to create a large impact on reducing engine wear and oil consumption – especially in Diesels. OEM’s through extensive research and development constantly raise the bar and it is becoming increasingly difficult, time consuming and in lot of cases virtually impossible for manufacturers to surpass OEM specs – given the level of honing technology that is predominantly used in the field today.

Typically smaller and midsized shops choose a conventional stroke honing machine or a single pass diamond sizing machine, and then try to “make do” with whatever they have. However, there are now honing systems available to small shops making expensive honing technologies used by OEM’s within reach.

Machines can now switch over from conventional stroke honing mode to single pass diamond sizing mode with the press of a button, giving manufacturing engineers the ability to reproduce OEM process in low and medium volume environment.

The ECO series honing system supports automatic tool-wear compensation during both conventional stroke honing mode as well as single pass diamond sizing mode. The ECO 40 hone have up to three honing and post-process gauging stations while the ECO 80 and 180 can have up to 2 honing and post process gauging stations. In a multi spindle set-up, a customer can choose to rough the part in single pass diamond sizing mode and finish the part in conventional stroke honing mode to achieve a particular cross hatch pattern.

Automatic tool-wear compensation system is integrated into the gauging system. Controlled by AB servos, the system monitors bore size on each part, and automatically compensates for tool wear by making fine submicron-level adjustments, ensuring bore accuracy.

In a manual compensation system, the operator has to measure the finished bore frequently in every station and manually compensate for tool wear. Over/under compensation is a common problem, leading to reduced control of bore size and excessive machine downtime, as the operator has to stop the machine frequently to compensate for tool wear.

In the conventional stroke honing mode, ECO honing system’s tool-wear compensation system minimizes non cutting time while improving bore quality. Once the tool is inserted in the bore, the tool expands at a rapid feed of 200 um/sec and at high torque (45% of available) until it reaches a predetermined position close to the bore. It will then switch to a rapid stock-removal mode of about 4 um/sec at lower torques (15% of available torque) to avoid tool damage. Toward the end of the cycle, the expansion rate is reduced to about 2 um/sec, or 10% of the available torque. The system constantly monitors both the tool feed (u/sec) and the applied torque (as % of available). If the desired feed is not reached at the preset torque, the operator can either reduce the tool expansion rate, if tighter tolerances are desired, or increase the torque, if quicker cycle times are needed. Tool expansion is rapid when there is no cutting, and is slowest for the final finishing cut, which results in a consistent bore in terms of finish, size, and cylindricity where there is form error such as taper, hourglass, barrel shape, ovality, bend, etc.

Typically roughing and finishing are performed in two different stations. However as illustrated in Figure 2, the Hydraulic expansion system coexists with the servo expansion system (described earlier) in the spindle and can be actuated independent of one another. This enables mounting of two different grits of abrasive tool in a single spindle.  Hence one could rough hone the part using the in-process gauging feature with the coarser abrasive using mechanical servo expansion (finer abrasives are drawn inside) and once the desired size is reached, the coarser abrasives withdraw finer abrasives perform finish honing utilizing the hydraulic expansion feature.  With the ability to gage, rough hone and finish hone in a single spindle, the system becomes very compact and flexible and easy to change over as there are no multiple stations and fixtures to changeover.

The expansion cone type tool design used in ECO hone’s single pass honing mode (Figure 3) is unique. When sleeves expand, cylindricity is not always maintained as the expansion occurs due to deformation of the sleeve when forced over a cone – at times there are some high and low spots. As a result, some sleeve type tools performs very well, while others need to discarded very quickly or will not cut at all. It is not uncommon for operators to go through a few tools before finding the one that works well. This inconsistency results in increased tool inventory levels. With the expansion cone design developed by Nagel, premeasured amount of abrasive is mixed in a centrifuge with metallic binder and sintered. The thorough mixing with centrifuge minimizes the variation in the distribution of the abrasives. Also the metal bonded abrasives are pre-dressed which results in “first part, good part”, thereby reducing the start up time after tool changeover.

In the existing sleeve type tool design, once the tool is worn out, the complete tool is typically discarded or sent back to manufacturer for restriping and plating. In the case of expansion cone design, the customer can immediately” remove the worn out abrasive and put in fresh abrasive sticks. Tool change becomes much more efficient as it need not be shipped back to manufacturer and also need not be restriped. This also helps in reducing the inventory of expensive complete tools. For example if a single pass machine were to have 3 stations, the tooling in each station has a different grit size and based on the production volumes, there will be number of back up tools for each grit sizes. However with the expansion cone design, the tool is common for all the stations (only the abrasive is different) thereby minimizing the backup tooling inventory.

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Sanjai Keshavan has many years of experience in the super finishing and honing industry. He is currently employed by Nagel Precision, Inc., a world leader in supplying honing and super finishing equipment that recently has developed equipment for lower volume shops. For more information, go to www.nagelusa.com, or contact Sanjai at 734-426-1812 or email: sanjai.keshavan@nagelusa.com.

For a PDF of this article (complete with photos), go to:
http://www.aera.org/ep/EPQ4-2011/index.html

The use of extremely low temperatures (cryogenic temperatures, which scientists define as below -244°F.) to boost the performance and service life of critical components is now commonplace in the racing industry and is becoming more and more prevalent in the manufacture of high quality components. What was once considered by many to be a questionable science is becoming a bedrock solid means of insuring the greater performance of materials.

Why has it taken this long to gain acceptance? It is extremely hard to get across to people that changes can be made using cold. People easily grasp the fact that heat can be made to modify solid materials. Heat treating is all around us.  Humans have been modifying metals with heat for over 7,000 years, and archeologists have found evidence that humans heated the rocks to make better tools with them over 140,000 years ago. So, the use of heat is second nature to most of us. We’ve only had extreme cold available to us in commercial quantities for about 100 years.

When you try to explain to people that you can permanently modify the performance of metals and other solid materials with cold, they tend to give you a cold stare of incredulity. They will tell you that the only thing you can do with cold is to cause the conversion of retained austenite into martensite, and you really don’t need to go very cold to do that.  (For those not familiar with the terms Austenite and Martensite, they refer to the crystal formation of hardened steels. Basically, you want only martensite for hardened steel but that is hard to get.) Martensite transformation is virtually finished at -140°F.

Going colder was considered just a waste of time. This attitude was (and is) so ingrained in people that when metallurgists started to create diagrams on how the atoms in a metal worked with each other at different temperatures, they went down to zero degrees Centigrade and stopped. But research into Deep Cryogenic Treatment started to show it works and that it works in materials where the old theories said it would not.  This finding has caused even the naysayers to take a second look.

In the last five years, the pace of research into cryogenic processing by major companies and universities has increased considerably. The focus of the research is also starting to change. Where it once spotlighted whether the process worked or not, it is starting to focus on why cryogenic processing works and what processing parameters are best for a given material.

The research is being helped tremendously by the Cryogenic Society of America. CSA is a non-profit technical society serving all those interested in any phase of cryogenics, the art and science of achieving extremely low temperatures — almost absolute zero. For more information, visit their website at www.cryogenicsociety.org.

CSA has created a database of research papers and informational articles that is available to anyone on the internet. This is a definite boon to serious researchers.

Cryogenic processing has also caught the attention of other entities. Jay Leno did a webcast on the subject. It is available at www.jaylenosgarage.com or www.metal-wear.com/Jay%20Leno.htm.

Air Liquide, a noted manufacturer of the liquid nitrogen used in cryogenic processing has bought processing equipment and has assigned personnel to research the process in their French research center (www.airliquide.com). They are also sponsoring research at Wayne State University in Detroit.

ASM, which is the professional society of materials scientists (www.asminternational.org) is now holding webinars and classes on the subject as well as devoting time for research papers through its Heat Treating Society.

One of the major commercial uses of cryogenic processing came out of the racing industry. The treatment of brake rotors and pads has been shown to be an economic boon to commercial fleets. Considerable testing was done by independent laboratories. Lab tests indicate a three to seven times increase in brake rotor life. Recently a county in California did a field test of brakes for its patrol cars. The results were that the county will save over $560,000 per year by equipping its 550 Ford Crown Victoria patrol cars with brakes treated with cryogenic processing. The savings include reduced costs of parts and labor.

Observed changes include:

• Increased resistance to abrasion

• Increased resistance to fatigue.

• Precipitation of very fine carbides in ferrous metals that contain carbide forming elements.

• Transformation of austenite to martensite in ferrous metals.

• Change in vibrational damping.

• Increased electrical conductivity.

• Anecdotal evidence of changes in heat transfer.

• Stabilization of metals to reduce warping under heat, stress, and vibration.

In practice, cryogenic processing affects the entire mass of the part. It is not a coating. This means that parts can be machined after treatment without losing the benefits of the process. Additionally, cryogenics apply to metals in general, not just ferrous metals. For many years, it was assumed the only change caused by extreme cold was the transformation of retained austenite to martensite in steel and iron. Because of this, many misinformed engineers still believe that cryogenic processing is “just a fix for bad heat treat.” It is now known that cryogenic processing has a definite effect on copper, titanium, carbide, silver, brass, bronze, aluminum, both austenitic and martensitic stainless steel, mild steel, and others. It is also known that plastics such as nylon and phenolics show property changes.

Racing Applications

Cryogenic processing can have a positive effect on virtually every engine, transmission, and drive line part, as well as many chassis parts. Increasing the durability of components in the vehicles is the main reason for using cryogenic processing. The great thing about cryogenic processing is that it allows an increase in durability without an increase in weight or major modifications to component design. In addition, the use of cryogenic processing has helped some racing teams reduce costs, enabling some expensive parts to survive the stresses of racing for use in subsequent races.

Performance Advantages

Brakes and Clutches. Brakes of a racing car take a real beating. It is not unusual for a racing vehicle to finish a race with the brakes totally worn out. This is especially true during road races and endurance racing, where brake rotors can get so hot they glow visibly at night. Cryogenic processing can be applied to both rotors and pads. The net result is two to three times the life of untreated components even under severe racing conditions. As a side benefit, the rotors are less prone to crack or warp. It is interesting that drivers report better braking action and feel. Some drivers are so sold on the concept that they have their street vehicle equipped with treated brakes. Clutches are a form of brake, and the results are very similar.

As an offshoot of racing development, cryogenically treated rotors and pads are making their way into fleet operations on the road. The U.S. Postal Service specifies cryogenic processing for their rotors and is experiencing up to five times as many miles as they were getting on the unprocessed rotors. Similarly, many police fleets are starting to adopt treated rotors and pads. They, too, are experiencing large maintenance savings on both parts and labor. What is metallurgically interesting is that the brakes are a gray cast iron that has a pearlitic structure. This rules-out the austenite to martensite transformation as the mechanism for increased life.

Springs

Springs fail in one of two modes. They either break or their spring constant starts to decline. Either way, it can have catastrophic effects on the performance of the vehicle. Most valve springs are made of specially made chrome silicon steel. The automotive valve spring is a fatigue failure waiting to happen. It typically can lose up to one third of its spring constant during a long race. In some forms of racing, it is just hoped that the valve springs will last through the race. Some drag racers routinely change the valve springs before every run down the drag strip to ensure consistent performance.

Typically valve springs exhibit a longer life after cryogenic processing. A recent doctoral thesis written by Ms. Debra Smith at Marquette University proved this. How much depends on the type of racing, the type of spring, the manufacturing lot of the spring and the criterion for a failure. Cryogenic processing of springs will usually triple the life before fatigue failure occurs, and it will reduce the amount of spring constant lost from 20 to 30% down to about 7%. This makes it easier to set up the engine, as there is not such a wide variation in the spring performance. It is difficult to determine absolute spring life increases, because the racers typically discard them long before they break. We do know one drag racer who used to change springs after each run: he now makes seven runs before changes. There is a caveat here. A further advantage for cryogenic processing of springs is that the process seems to eliminate or reduce harmonic vibrations. If you have ever seen a high-speed movie of a valve spring at high engine rpm, you will notice that the spring does not simply move up and down. It does a very complex hula dance because of the harmonic vibrations. Racers typically have to design the spring and valve trains so that harmonics do not interfere with the valve action.

Not unexpectedly, chassis springs are also affected by cryogenic processing. Chassis springs lose their spring constant during a race. This can cause the chassis to lose its cornering ability, which drastically slows the car. Loss of spring constant also alters the height or road clearance of the vehicle. The vehicle height is critical at high speeds because it has a big effect on the aerodynamics of the car, and hence on the handling and the top speed of the car. Other ramifications of springs sagging are evident. Watch the pit crew after a Sprint Cup race as the car is pushed up on to a platform for inspection. If the springs have settled too much, the car may be disqualified as it will sit too low. So the pit crew will often be lifting on the chassis as they roll it along to set it up a little higher. When they get the car to the measuring surface, they gently let it down so it does not bounce and settle farther than necessary.

The Chassis

The chassis itself is basically a very large, complex spring, having numerous welds and using not very precise tubing. The metals used here vary, depending on the type of racing. NASCAR frames are made from 1020 steel; other forms of racing use 4140 steel. Of course, other high strength, lightweight materials are also used. As the chassis experiences vibration during the race, residual stresses in the welds and the tubing can start to relieve. This causes the chassis to change shape during the race, affecting the handling of the vehicle and therefore its speed.

Gears, Shafts and Assemblies

A study for the U. S. Army Aviation and Missile Command, by the Illinois Institute of Technology Research Institute concluded that cryogenic processing of carburized 9310 steel increased the gear contact fatigue life by 100%, and the ability of the gear to handle load by 10% over the same material that had undergone a -84°C(-120°F) cold treatment per military specification. They also found that the conversion of retained austenite is only part of the effect on the gear. Most racing gears are 9310 carburized steel, although 8620 is also used. One major racing transmission maker, after inspecting numerous gearboxes after races, has ascertained that cryogenic processing cuts the gear wear dramatically. This also holds true for road racers of Porsches and BMW’s and other SCCA race cars who are now getting about three times the life on their gear boxes. Cryogenic processing also increases the life of other heavily loaded gears. We see a doubling of the life of ring and pinion gears in differentials, even under such severe usage as tractor pulls. Quick-change gears also show dramatic increases in life. Axle shafts, universal joints, and constant velocity joints all show dramatic increases in durability. As the racing of front wheel drive cars becomes more popular, we begin to see more and more constant velocity joints being processed, as this is one of the weak points of the drive line. Axles are treated to stave off fatigue failures in the splines.

Engines

Virtually every part of an engine will respond to cryogenic processing, with all components exhibiting life increases. Several component manufacturers are starting to take advantage of this and are treating their racing components as part of their production. Some of the main applications are:

• Connecting rods usually fail in fatigue. This occurs because of the high “g” loading of the piston and pin. Sprint Cup engines currently run around 9300 rpm. They have a stroke of around 86mm (3.375 in.) Pistons and pins typically have a mass of around 650 grams (23 oz.). Given these figures, it can be calculated that the upward force the piston and piston pin exerts on the connecting rod during the exhaust stroke is over 4800 g’s. Although this calculation ignores the weight of the small end of the connecting rod, it can be seen that there is a repeated stress on the rod, which has a cross sectional area of under 230 mm2 (0.35 in.2). Cryogenic processing increases the fatigue life of connecting rods considerably. We process steel, titanium and aluminum rods. The steel rods are generally AISI 4340 or 300M steel, aluminum rods are usually 7075 T6.

• Cylinder heads: Both aluminum and cast iron heads usually fail by cracking, which results from both thermal cyclic fatigue and the flexing of the head under combustion pressures. Further, the heads are often subjected to the extreme pressures created when the fuel mixture detonates. All these pressures can cause the head to flex so much that it is not unusual to find debris such as piston coatings under the heat gasket, blown there during a combustion stroke. Several Sprint Cup teams have concluded that 356 T6 aluminum heads yield about double the life after cryogenic processing. Other racers have the heads (both aluminum and cast iron) treated as a matter of routine. Of course, treating the heads increases the life of valve seats and valve guides. It is interesting to note that the heads can be treated with the valve guides and seats installed.

• Camshafts and lifters: Roller lifters usually fail by breaking, some of which is just poor design with sharp edges and stress risers all over. Even so, one customer reports that he gets about five runs down the drag strip unless he cryogenically processes his lifters. After cryogenic processing, he typically gets over 100 runs. Sprint Cup rules specify solid lifters. These cars are turning around 9300 rpm, so valve spring pressures have to be very high to slam the valve shut. The current practice is to create a cam profile that will actually loft the lifter. The lifter is thrown up in the air, forcing the valve to open very fast and then the spring slams the lifter down back against the cam. This creates extreme wear, but it gets the valve wide open as quickly as possible and leaves it wide open to the last possible microsecond. The lifters start with a slightly convex surface and wear into a concave configuration. Typically, they are cast iron and heat treated to the mid 50’s HRC. In use, any wear increases the valve lash and delays valve lift, creating a loss of power. It also leaves a lot of wear particles in the oil. It can take up to three sets of lifters to get an engine through dyno testing and the race due to the extreme wear caused by these radical cam profiles and high spring pressures. Cryogenic processing reduces this wear by about half. Camshaft wear is also a problem. Cryogenic processing has proven a boon to these racers because it reduces wear and therefore reduces camshaft replacement costs.

• Bearings: At least one racing bearing manufacturer cryogenically treats babbited bearings as part of their production process. They found it increased the life of the bearings and also of the steel backing, which tended to fail in fatigue. It is interesting that CRYOGENIC PROCESSING has an effect on the babbit metal of the bearings. Similarly, bronze bushings used on wrist pins also wear considerably less when treated. Many racers are processing ball bearings and roller bearings (typically 52100 steel) because they get a three to five fold increase in life. Rod ends used in steering and suspension systems get the same treatment and performance gains.

Cylinders, Pistons and Rings

Cryogenic processing of piston rings and cylinder walls has been shown to reduce wear substantially. One go kart racing customer claimed that he got a fivefold increase in engine life before he had to freshen the engine. Better ring seal was born out in pressure readings on a dynamometer. Apparently, this happens because the parts machine and hone better after treatment as a consequence of a more uniform hardness distribution over the surface of the part. CTP has done tests that show a significant reduction in the standard deviation of hardness readings taken before and after cryogenic processing. In some cases, the standard deviation is one third of what it was before the process. Processed piston rings typically wear both less and more evenly than untreated rings. More tribologically compatible with the cylinder walls, they tend to flutter less due to the vibrational damping the process imparts into the material and due to the more even hardness of both the rings and the cylinder walls. All these factors combine to give better ring sealing, and therefore more power.

Cryogenic processing of engine blocks also stabilizes the blocks and reduces warping and distortion due to vibration and heat during use. Caution is needed here because if the process is not done right, it can cause warping.  Typically an untreated cast iron engine block will have readings that vary from 20 to 29 on the Rockwell D scale. After cryogenic treatment the readings will be 22 to 23. Blocks cast with CGI typically measure 19 to 31HRc before treatment and 25 to 26 afterward. Some of our Pro Stock drag racing customers tell us that they only need to hone the cylinders .0002” when freshening the engine due to the stability of the blocs after treatment.

The same is true for pistons. Several engine builders, who specify the process, have taken careful measurements of pistons before and after use, finding that cryogenically processed pistons distort less under use. Crankshafts benefit greatly from cryogenics. Several of the most respected names in the crankshaft business use cryogenics as a part of their thermal treatment. Cryogenic processing greatly decreases wear on crankshaft journals and stabilizes the crankshaft. We have treated everything from stock cranks through special racing nodular iron cranks and racing cranks made of 4340 steel. DCT is virtually mandatory in racing classes that specify production crankshafts if you want the crankshaft to survive.

Virtually all parts that are subject to stress or abrasion can benefit from cryogenic processing. Even head gaskets benefit because the armor around the combustion chamber is subject to both thermal cyclic fatigue and to flexing fatigue.

Keys to the Process

Success of cryogenic processing is critically dependent on the equipment in which the processing is done. There are companies that will dip your components in liquid nitrogen and pronounce them “treated.” For a good look at why this is a bad idea, go to www.youtube.com/watch?v=yg45ILXZ26w. This is a video where two Lincoln Laboratory scientists put a rubber stopper into liquid nitrogen. The result is that it explodes. Metal parts are stressed in much the same way by immersion. They may not explode, but they can crack and achieve very high levels of tensile residual stress.

The best cycles are those that reduce the temperature of the part slowly, typically going down to -300°F in eight hours or more. The part should then be held at -300°F for an extended time that depends on the material being processed. Research is indicating that the time at

-300°F is very dependent on the alloy being processes. The hold part of the cycle can be as short as 8 hours or as long as 60. The hold part of the cycle is followed by a slow rise in temperature to ambient.  Many alloys need at least one heat tempering cycle to finish the process.

The quality and function of the machines available varies from very poor to excellent. (We’ve seen a Styrofoam beer cooler touted as a processing machine.)

So does the ability of cryoprocessor manufacturers to support their machines with technical and processing advice. The best machines are ones that use a heat exchanger to cool the parts. Vacuum insulated machines are more efficient in their use of liquid nitrogen. This keeps costs down as liquid nitrogen is a major expense in the process.

Cryogenic processing is an economic means of extending performance of metals. It has been proven on the race track, in the laboratory, on the road and on the production lines of industry.

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Roger Schiradelly and Rick Diekman of Controlled Thermal Processing, Inc. have over 10 years of experience with cryogenic processing. Roger works out of the Mooresville, N.C. plant and is a specialist in racing technology, with over forty years of experience in racing. Rick works out of the Park City, Ill. plant and is the chairman of the ASM Cryogenic Processing Committee. For more information, go online: www.metal-wear.com.

For a PDF of this article (complete with photos), go to:
http://www.aera.org/ep/EPQ4-2011/index.html

From the Editor: The internal aerodynamics of a four cycle engine intake tract are thought to be understood by many people. In reality, very few in the world understand it completely. Keith Wilson has proven himself as one who does understand. What follows is information from the man himself.

Let me start be relating something that everyone understands and has experienced at one time or another: the common cold. Remember a feeling of having to work hard to inhale every breath that was restricted. Of course the cold does go away and it is so much easier to breathe because of less restriction.

The trick is making spacer plates and intake manifolds which allow increased air flow into the engine.

Reducing intake track restrictions allows the engine to ingest, consume or breathe in more air allowing the possibility of higher power production. Why do I say the possibility of higher power production? Because, no matter if the engine is forced induction, naturally aspirated with a carburetor or fuel injection, one thing is constant across the board. Rule # 1: If the mixture enters the combustion chamber in big droplets, you will lose power!

In order for an engine to make more power than before, it must have the ability to refill each cylinder more completely with every intake stroke. As you have already learned, you also must keep the mixture of air with fuel in suspension. The mixture must stay emulsified all the way into the cylinder or big droplets of fuel occur and the engine’s power suffers. This seems to be such an easy thing to say but it is so much harder to accomplish inside the intake tract. Always refer to rule #1: Big droplets of fuel cost you power, period!

Carburetor spacers correct for the application are a cost effective form of tuning hardware. (See Figure 1.)

Carburetor spacer attaches to the intake manifold, between the carburetor and the carburetor mounting pad, more precisely to the top of the intake manifold plenum. The intake charge (the fuel and air mixed together) mixture exits the throttle body of the carburetor and flows through the spacer into the manifold plenum. There it is distributed to the individual runners and on into the ports of the cylinder head.

For the best engine performance, charge distribution in the intake manifold needs to be even so that each of the engines cylinders not only receives the same strength but enjoys a uniform level of volumetric efficiency. If the distribution is uniform but the emulsification of the fuel mixing with air is uneven, performance will suffer.

The purpose of any carburetor spacer is to correct the fuel mixing and charge distribution issues that are inherent in every intake manifold design. It accomplishes this by manipulating the charge to improve the vaporization of the fuel and steer it more uniformly to every bore. It simply allows the intake manifold and carburetor to work more efficiently with the spacer in place. Adding the correct spacer can take a bad or ok situation into a very good functioning carburetor and intake solution. With that said, carburetor spacer plates are still best bang for the racer’s buck.

Currently there are four distinct styles of spacers on the market each with its own influence on the intake manifold. An open spacer increases plenum volume, working best in very high rpm applications. (See Figure 1.) A four-hole spacer favors low end torque, designed for lower engine speeds, and has the possibility to aid fuel reversion with increased cam overlap. (See Figure 2.) An adapter spacer is used to mate a carburetor to an intake manifold with a different bolt pattern. Traditionally, these spacers impede performance but allow the use of many different carburetors to be used on an existing intake manifold.

And finally, we have a new spacer theory that features a tapered bore with the promise of a large power gain with almost every intake manifold. Where the open spacer increases plenum volume, the tapered 4-hole spacer increases CFM (airflow). (See Figure 2.)

When additional plenum volume is not required, the tapered spacer is the more effective of the two—enhancing air flow to the carburetor or throttle body. The design of the taper is very intricate and is partially a function of the height of the spacer. It is able to increase air flow through the carburetor because a venturi effect is created at the top of the spacer just below the throttle plates. This causes the carburetor to flow more air through the booster. Then as the air travels through the spacer, the bore is widened to slow the charge down as it prepares to turn toward the manifold runner. (See Figure 2.)

Shear plates are another form of spacer that is attached to the top panel of a sheet metal intake, situated underneath the carburetor. Because the sleeve extensions protrude down through the top panel, they serve to obstruct the reversion pulses and therefore, restrain the induction charge from escaping backwards up through the four holes and past into the carburetor. (See Figure 3.)

Sheet metal intake manifolds allow the very latest in manifold technology to be built in a short amount of time. That allows each intake manifold to be custom designed exactly for the engine application. In some applications the use of a spring-loaded burst panel on some of my sheet metal intakes. Typically there is one on each flank between the runners with each assembly comprising of two plates, an inner and an outer, with an

O-ring sandwiched between the plates. If the engine back fires the spring-loaded outer plates open to relieve the excessive high pressure and immediately reseal. Especially effective on Nitrous applications, racers quickly realize the benefits that these panels add a safety factor for saving the intake manifold and carburetors from destructive backfires.

Racers using Electronic Fuel Injection (EFI): a considerable amount of time has been spent researching fuel injector flow spray patterns into the intake tract. Every week I get approximately ten engine builders request Wilson Manifolds to install injector bosses in their intakes. This is a tedious job, for the injectors need to be aimed at the intake tract at a precise angle — not just welded in anywhere. If the angle is incorrect and the fuel mist hits a wall, you’ll lose your vapors as they degrade into big droplets (refer to Rule #1) and enter the chamber in less than perfect form. Fuel rails must be solidly attached to the intake manifold. A fuel injection conversion kit without correctly installed injector bosses or securely welded fuel rail stanchions is terribly inadequate (see Figure 11).

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Keith Wilson has dedicated his working life to airflow or engine internal aerodynamics. At 17-years old, he was employed by a Florida company called Air Speed Engineering. There he spent ten years of his life learning how to improve airflow through cylinder heads and intake manifolds. In 1985 he branched out on his own and formed Wilson Manifolds. Very quickly he seized the opportunity to not only rework cast aluminum intake manifolds, but to explore his theories on cylinder filling. On a clean sheet of paper he designed and constructed of sheet metal his own new style of intake manifold. No longer being limited by the cast intake manifolds produced at that time, it allowed him to apply his knowledge to construct sheet metal intake manifolds with whatever type of port taper, port length, cross-section and plenum volume that he would like. Little did he know that he was about to revolutionize the intake manifold industry. For more information, please contact Keith Wilson at Wilson Manifolds, Fort Lauderdale, FL. Call 954-771-6216 or go online: www.wilsonmanifolds.com.

For a PDF of this article (complete with photos), go to:
http://www.aera.org/ep/EPQ4-2011/index.html

Determining the proper centerline of a camshaft lobe to the existing centerline of the engine block lifter bore has never been easier when using a new tool developed by Schumann Sales and Service.

Cam manufacturers and engine builders all recognize the fact that the centerline of the cam lobe and the centerline of the lifter bore must coincide in order to use optimum high pressure valve springs with fast rate of lift, solid flat tappet camshafts.  Have you ever tried to eyeball this alignment? The critical ideal misalignment is plus or minus .015” of coinciding centerlines. Some manufacturers and engine builders spend tremendous amounts of time determining the 16 centerlines required.

This new tool will guarantee proper alignment in 10 minutes or less. Simply install the new camshaft with a thin coating of alcohol quick dry layout blue dye or a thin layer of blue paste layout dye on each lobe. Then, secure the timing cam timing gear assembly to establish the depth of the cam to the engine block assembly used. Next, insert the cam/lifter body centerline checking tool into a lifter bore, apply light thumb pressure to the top rim of the tool while turning the camshaft over one complete revolution. Doing so will show the actual centerline scribed onto the cam lobe by the nylon adjustable centering scribe on the tool body base. Repeat this process fifteen more times and carefully remove the camshaft to evaluate match or mismatch of each lifter bore/lobe alignment.

If your misalignment is on the high side of the taper inclination of the cam lobe, a higher incidence of lifter rotation with a smaller contact footprint available and results in a higher psi present at the wear pattern.

If your misalignment is on the low side of the taper inclination of the cam lobe, a lower incidence of lifter rotation with a larger contact footprint available and results in a lower psi present at the wear pattern.

Obviously, dead center alignment creates the acceptable lifter rotation and acceptable psi load ratings.

Please note that there are five cam blank manufacturers commonly used in aftermarket camshafts, two are domestic USA, two in Asia and one in Mexico. Guess what? None of the five coincide with the centerline spacing and there are three different load widths among the five.

If you want to maximize camshaft performance, serious attention must be concentrated on this centerline issue.

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LaVern Schumann, Jr. is the president of Schumann’s Sales & Service, Inc. in Blue Grass, Iowa. For more information, please contact him at 563-381-2416.

For a PDF of this article (complete with photos), go to:
http://www.aera.org/ep/EPQ4-2011/index.html

Nothing undermines the legitimacy of a connecting rod maker more than a deficient batch of rods. They agonize constantly about heat treatments, high revs, heavy pistons, heavy pins, the number of race laps between rebuilds, but probably most of all whether or not nitrous is being sprayed. It’s a complicated business determining minimum weight while yielding maximum strength, enough to withstand the abuse sustained by the average race motor.

Lunati overcomes these special problems with their I-beam Signature series connecting rods by forging them in 4340, a very tough material with high nickel and high molybdenum content. In fact, the chemical constituents of the rods are almost identical to the dies from which they are forged. Probably the chief reason they consistently withstand high impact loads at high temperatures is because the manufacturing process is closely governed in a batch furnace. To this end the controlled quenching procedures and elaborate racking maintain the stability of these accomplished connecting rods during heat treatment.

Though Magnaflux testing, which uses dust in a magnetic field to reveal cracks on the surface of the connecting rod, has been in use for decades, “It was sonic testing,” says Lunati’s Derek Scott, “that has had the most profound effect on the quality of Lunati’s connecting rods.” In use for most of this decade, sonic testing is characterized by a sound wave transmitted through the metal, and reveals any hidden internal inclusions. Under high stress conditions, inclusions or ‘cold shuts’ can be fatal to the connecting rod’s longevity.

For practical reasons, most Ford high performance and competition engine builders in the States use cranks with 2.100” crank pin journals as opposed to the conventional Ford 2.311” journals. The smaller journals reduce bearing surface speeds, the larger the bearing the greater the surface speed. In addition the extra width of .940” compared with Ford’s width of .830” adds strength to the rod. And beyond this 2.100” rods are less expensive yet readily available in a multitude of enticing stroke lengths.

Here in the following sequence of pictures are the 24 major operations undertaken in the production of a high quality Lunati Signature series connecting rod.

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Victor Moore, who writes under the pseudonym Sam Logan, was born in a village near Ballymena, Northern Ireland. After his education he immigrated to Australia, where he began his career in sales with British Tube Mills in Sydney, NSW.  While there he competed regularly in the local road racing scene and eventually returned to the UK where he formed a fabricating company near Peterborough, Cambridgeshire. His firm specialized in the design of prototype and production chassis and associated components for sports and racing cars. In the 1990s he immigrated to the United States, where with his American wife, Susan, he formed an agency known as Moore Good Ink, specializing in advertising, the promotion of race car parts, and technical writing.

For a PDF of this article (complete with photos), go to:
http://www.aera.org/ep/EPQ4-2011/index.html