50 Years of the Small Block Engine Parts

Other better/cheaper innovations: lighter, thinner, die-cast cylinder heads that were interchangeable side to side and employed a small wedge-shaped combustion chamber requiring minimal machining and providing high turbulence. A radical new block casting method needed about half as many cores as usual, and they were far less likely to shift during casting. This precision allowed cylinder walls to be as thin as 0.156 inch, which reduced mass dramatically so the V-8 weighed 41 pounds less than Chevy's Blue Flame inline-six and 50 pounds under Ford's flathead V-8 that was the darling of the hot-rodding set. Less iron holds less heat, and with a full water jacket around each cylinder and around each exhaust port, the 265-cubic-inch 162-to-180-horse V-8 ran cool enough to use a seven-percent-smaller radiator than the 235-cubic-inch 123-horse six needed.

Much of the engine was released for tooling right from the drawing board and revised during the development phase to correct problems. "We used one of the first radioactive oil tests," recalls Ralph Johnson, a coop student in the dyno lab at the time, "to examine oil under black light to prove the problem was ring wear." The lack of an oil filter probably didn't help things, but this upgrade wasn't added until 1956. "Sometimes sealing also was a problem. The split crankshaft seals eventually gave way to a full-diameter seal," Ralph adds. Bob Papenguth recalls a local overheating problem around the spark plug that required a revision to the water jacket in the cylinder head. "The manufacturing guys corrected the problem fast. It amazed me how well the manufacturing organization responded to the changes design made." The plugs themselves were vulnerable to heat from the exhaust manifolds, which were routed up and over them, but heat shielding solved the problem. And, just like that, most shortcomings revealed in development were solved quickly.

Ralph Johnson sums up the period: "You worked hard and you played hard. Could some of these guys be dirty rotten bastards? Of course. But for a two-year time frame, this team did a mighty fine job."

There's no doubting that statement with the benefit of 50 years' hindsight. An instant hit, almost 750,000 mouse motors were built in that first year. Six hundred seventy-four of them, tuned for 195 horses with solid lifters and a Zora Arkus-Duntov cam, went into Corvettes. Despite its greatly improved performance, Vette sales languished, so Cole cleared Chevrolet to go racing at Daytona Beach, Pikes Peak, Sebring, and other venues. In 1957, the engine was bored out to 283 cubic inches, and the General's first fuel-injection system became available, boosting output to one horsepower per cubic inch.

That year, Chevrolet won at the Darlington superspeedway, and the die was cast. The performance potential of the small-block was established. The aftermarket migrated away from the ancient flathead Ford and tooled up to feed a market hungry for Chevy power--and the momentum has been building ever since.