24 things you need to know
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.
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.
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.
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