Whether you think that Camaro made the 302 or that the 302 made the Camaro, the fact is that Trans Am racing created both of them.
Long before the concept of turning right was forgotten to history, America fell in love with a little racing series known as Trans Am. In the same way that NASCAR drove the development of mega-cubic-inch, full-sized cars, Trans Am was responsible for molding pony cars into the forms that we love today. Chevrolet designed their 302-cubic-inch engine for one purpose only -- to crush all who stood in the Camaro's path to victory.
Dawn of the Small Block
Introduced in 1955, Chevy's small-block was the right engine at the right time for GM. Barely 10 years before, the Ford flat-head was the hottest engine on the block, and the motivating force behind most hot rods and performance cars of the day. Overhead-valve V-8s like the small-block hit the American automotive scene like a .50-cal bullet, ripping through Ford's dominance of the performance car market and forever altering America's definition of horsepower.
Trans Am Series
Bill France's National Stock Car Association had been influencing American car culture for over 15 years when Trans Am officially organized in 1966. NASCAR wasn't completely devoid of road-course races, but the series was more geared toward large sedans than the lightweight sports cars popular in Europe and Japan. Trans Am had two basic classes: "under two liters" (comprising mainly small European sports cars) and "under five liters," or 302 cubic inches.
The 302 in Racing
Chevrolet created the Camaro not only to compete with the Ford Mustang on the street, but to crush it in Trans Am racing as well. The 289-cubic-inch Mustang had dominated the first season of Trans Am racing, but Chevy had a plan. To power its newest competition Camaros, Chevy dropped the crankshaft from a 283 into a 350 engine block to yield a class-compliant 302 cubic inches. While the 302 did indeed bring Chevrolet a number of victories during its two-year production run, GM decided to drop the engine for its 1970 Camaro redesign. On the street and in sales offices, "302" was Ford's and "350" was Chevy's, and that's the way it would stay.
Engine Design
GM rated the 302 engine at 290 horsepower, but that was about 85 horsepower shy of the engine's true output in stock form. In racing trim, the 302 was good for over 500 at the crankshaft. The secret to this engine's success was its "oversquare" design. An oversquare engine is one which uses a larger bore than stroke to enhance airflow relative to rpm, thus allowing the engine to reach much higher rpm before losing its punch.
Engine Specs
The 302 used block casting number 3892657, crank casting number 3815822 and one of two "double hump" heads with 2.02-inch intake and 1.60-inch exhaust valves. For the 302, GM lifted the camshaft from their other high performance small block -- the 375-horsepower, fuel-injected, Corvette-only 327 V-8. This "30/30" cam was so-called for 0.030-inch valve lash settings for the intake and exhaust valves. It measured 0.452-inch lift and 229 degrees duration at 0.050-inch lift (intake) and 0.455-inch lift and 237 degrees duration at 0.050 for the exhaust.
