Quote:
Originally Posted by GH85Carrera
In the early years of Pro Stock racing the weight factors were very important. Smaller engines ran in lighter cars. Bill Jenkins decided that a 331 cubic inch small block Chevy was optimal.
He installed a small journal 327 crankshaft with bearing spacers into a 350 4-bolt main block. He decided that 5.85 inch long connecting rods were the best length (5.70 is stock). Then he bored the block .030 oversize.
When he installed it into his Vega he won so many races that he was considered the highest paid athlete that year. |
"Smaller engines ran in lighter cars", while technically true, is far from the whole story. When the NHRA created the Pro Stock class, all cars were required to weigh seven pounds for every cubic inch of displacement. It only took a couple of years for it to become obvious that the only combination that was competitive was the Chrysler 426 Hemi, usually in an "E" bodied car, like the Challenger or Barracuda. Neither Chevy nor Ford had anything even remotely competitive.
So what did they do? Instead of rolling up their sleeves and getting to work in an effort to come up with a competitive combination, they went to the NHRA and whined. The end result was the NHRA granting "wedge" motors (like the small block Chev, Ford 351 Windsor, etc.) a huge advantage - they only had to weigh 6.5 pounds per cubic inch. Canted valve motors (big block Chev, Ford 351 Cleveland, 428, and 429) could run 6.75 pounds per cubic inch. The Hemi cars were kept at 7.0 pounds per cubic inch.
So, no, Bill Jenkins was not some sort of mastermind with the small block Chev. He was incapable of winning on a level playing field which, to be fair, was only due to his loyalty to Chevrolet. He did, after all, beat everyone else who was running small block Chevs, so there is that.
Interestingly, before he died, he helped Chevrolet with a canted valve head for the small block. He saw the limitations of the wedge head (probably more clearly than anyone else), and set about to correct all of that. Only 30 years after Smokey Yunick had fabricated a set for his Trans Am Camero, but what the hell. Great minds think alike, I guess, even if it took 30 years for the second greatest small block man to catch up to the first...
