In terms of weight fluctuation, the tolerances are tightly maintained. The whole part is weighed and must fall within a total tolerance area. In the case of the connecting rods, by the nature of the part's design, the pin end has a 6 percent tolerance while the crank end has a 2 percent tolerance.
GKN has the capability of making 130,000 rods daily. The material used in the rods is ASTM 4260, which, in many ways, is superior to 4340 steel. The metal standard was established by ASTM International, formerly known as the American Society of Testing and Materials.
The rods will be made in America and can be easily reworked by using oversized bearings available from three different manufacturers. Initially, the rod has become available for the small-block Chevrolet applications. The cost savings was expected to reduce the racers' budget by as much as 40 percent in comparison to units of similar quality. Top quality rod sets, equally matched, are expected to cost $600 at the retail level. The target weight of the small-block Chevy rods is between 500 and 600 grams, and the approximate horsepower range is between 700 and 800.
The search for better technology has found the powder metal application starting at this point, but the drive to find more use is clearly underway. The methodology and materials have been proven in lab tests, product tests, and real life applications. Racers looking for competitive alternatives have to consider the advantages found in powder metal. If they don't, their competition will. CT
Editor's Note: Special thanks to Al Barra for research and material provided.