The Series 60 Detroit Diesel Corporation has proven to be more than a serious competitor in the diesel engine market for more than two decades. A few years ago the Series 60 heavy-duty diesel engine was recognized by Diesel Power Magazine as the number two ranked “Best Diesel Engine Ever” on a list compiled by that publication. The number one ranking went to Rudolph Diesel’s first working diesel engine. Rudolph Diesel is considered the “father” of the modern diesel engine, imagine that.
This engine series is available in three displacements (11.1, 12.7 & 14.0L) offering power ranges from 425 to 515 horsepower for the on-highway and vocational markets. Since 1992, the Series 60 engine has been the most popular heavy-duty truck engine for more than twenty years in the Class 8 market based on R.L. Polk registrations.
In just over twenty short years of manufacturing these engines, DDC produced its one-millionth engine in 2008. These engines have proven significant fuel economy savings and durability over other engines in the same class. This is a major concern for fleet owners as fuel prices continue to climb. There is one rental truck company that has used more than 75,000 engines since 1990.
The rapid acceptance of EGR in 2004, allowed DDC to ship over 49,000 Series 60 engines with EGR, bringing the field population of Series 60 engines with EGR to over 80,000 units in a very short time period. Further refinements allowed DDC to reach the tougher 2007 diesel emission standards and pave the way toward the stringent 2010 standards.
Exhaust Gas Recirculation systems have been optimized to dramatically cut NOx formation by routing a measured amount of exhaust flow to the cylinders to lower combustion temperatures. The newly designed system features a high-capacity, tube-and-shell EGR cooler that is more rugged than the previous model. Because coolant is the system’s lifeblood, they enhanced the water pump for greater output, and changed to a partial-flow stream inside the EGR cooler. The EGR valve, now located on the cool side of the engine, is new as well.
Exhaust Aftertreatment System
The biggest change to the engine is the addition of an exhaust Aftertreatment System, which replaces the muffler assembly in the exhaust system. The unit’s defining components are a Diesel Oxidation Catalyst and a Diesel Particulate Filter that oxidize – or burn – soot. During normal highway operation, exhaust temperatures alone are usually high enough to burn off accumulating soot, a process known as “passive regeneration.” In low ambient temperatures, however, or in some stop-and-go applications, the system needs a little help to regenerate, or clean itself. This process is called “active regeneration.”
The Aftertreatment System uses a “doser” to initiate active regeneration. When the amount of soot inside reaches a certain level, the doser injects a measured amount of diesel fuel into the exhaust flow, which reacts with the catalyst to raise the temperature to a point that enables regeneration. There are two types of active regeneration: in-transit and stationary. In-transit regeneration occurs when the truck is in motion. When the truck’s driving cycle is insufficient for in-transit active regeneration, stationary active regeneration is required. This is performed when the truck is parked and monitored by the driver or a service technician.
The intake throttle also assists in the regeneration process. When necessary, this device limits the amount of air entering the engine, raising the exhaust temperature and facilitating regeneration.
ULTRA LOW SULFUR DIESEL (ULSD) Fuel and CJ-4 Oil
The Series 60 is designed to run on ULSD fuel, which can contain no more than 15 PPM sulfur. The current maximum sulfur content for on-highway diesel fuel is 500 PPM. ULSD fuel is necessary to avoid fouling the engine’s Aftertreatment System. A new low ash oil formulation, designated CJ-4, is recommended in EPA ‘07 and newer engines. CJ-4 oil contains less than 1.0 wt. % sulfated ash. Use of high ash engine oils will reduce the cleaning interval on the Diesel Particulate Filter system.
Electronic Variable Geometry Turbocharger
Engine performance starts with low-end throttle response. The Series 60 uses an electronic variable geometry turbocharger that automatically and precisely adjusts its boost across the operating range, delivering quick and punchy lift on the low end, where turbo lag would otherwise occur.
What does this all mean for engine builders? Well, one thing that is certain, it is a lot easier to sell an engine build to someone who is extremely satisfied with the previous usage of an engine than one who has not been. Aftermarket engine parts have been available for several years as indicated in the chart and ad (pictured at right).
It’s been reported this engine’s durability may not present as many machining operations to remanufacture the engine, but don’t let that stop you from going after these customers. There is still plenty of opportunity to clean, qualify and assemble the major engine components. Most of the machining will occur on the engine’s massive, 24 valve, overhead cam cylinder head.
2007 and newer engines incorporate a new N3 injector requiring a cylinder head modification to secure it in the head. These heads now have what Detroit Diesel calls an Injector Tube which screws into a threaded area where an injector sleeve used to be. This idea may have been borrowed from much older Caterpillar engines of thirty years ago. The removal and installation of these tubes requires a special tool (Part #J-46904 or J-48824).
Many Hot Rod performance modifications are also available, such as a more durable turbo which suggests improved performance and 5-10% better fuel economy.
These engines are becoming more and more popular for tractor sled pulling events on a huge scale with horsepower reaching well over 1000. There are numerous computer chips that can be purchased to modify power range curves for specific applications as well.
To dramatize the durability of the Series 60 engines, the Detroit Diesel Corporation disassembled and photographed the major engine components to exemplify what they’ve deemed “average” wear that should be found on an engine with 250,000 miles. (See page 13.)
It should also be noted that the engine was operated and maintained following the maintenance schedule for 60 Series engines.
The cylinder head offers the most machining possibilities in this engine as each camshaft is supported by insert type cam bearings. Three different oversize camshaft bearings are available to allow salvage operations when a bearing bore is out of specification. Be sure to see AERA Technical Bulletin TB-1989 for additional details concerning camshaft bore repairs.
A majority of the Series 60 engines have recorded over a million miles and many of those truck owners often report “they won’t drive anything else”. The newest year model engines have more than exceeded the new 2010 year model emission requirements and continued sales promise to keep this engine as the “engine of choice”, possibly for another twenty years.
Dave Hagen, our Senior Technician, has over 36 years of experience in our industry. As an ASE-certified Master Machinist, Dave specialized in cylinder head work and complete engine assembly for the first 17 years of his career.
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