As the engine displacement increased from .70 to .97 cu in; the connecting rod length increased; the stroke remained the same; & the bore increased, new fixtures were required. In the upper right hand corner, is one of the first hardened steel (S-7) "I" beam connecting rods mounted on the grinding fixture.. It's center distance was 1.656. This center distance is now 1.741. All of these S-7 rods have been tested at 32,000+ rpm with no failures.
