Mar 20

Small block Chevy V8 part III: The 302

We continue our series after a bit of a hiatus with the legendary 302 engine which was a race engine. The 302 was produced from the 4 in bore family of small blocks and the displacement was achieved by adding the crank from a 283. This engine was build with the purpose of racing in the SCCA’s Trans Am series. It’s forged steel crank, large main journals, 4 bolt main and three bolt centers made it nearly bullet proof and extremely reliable for racing. Due to the nature of it’s geometry and “097” cam set up it was a high revving engine for it’s time. The stock cam made 360hp but with the hotter “off road” cam the engine made 400hp@5800 RPMs.

In 1967 and 1968 the production cars would have cowl induction that came in just above the firewall on the passanger side. This had the disadvantage of routing the air right above the heater core which legend says actually increased the air of the intake charge. This was cured in 1969 with the introduction of the ZL-2 cowl induction hood which brought air to the intake via a sealed passage insuring cold dense air made it into the engine.

The 302 enjoyed great success in racing winning the Trans Am championships in 1968 and 1969 with Mark Donohue piloting the car. The 302 also powered the Formula 5000 series from 1968 to 1976. Many of the advances made in the 302 for racing would make their way to street engines in the future such as cross ram induction, the use of the improved Delco transistor ignition system which was much more stable at high engine speeds then the old breaker point system, and the use of higher pressure valve springs for a higher revving engine.

While the 302 wasn’t the most popular of small block Chevy’s it is a highly sought after engine for restorations and Trans Am cloned Camaros. It was high successful in racing and proved to be extremely durable. That’s why the 302 is a legendary small block Chevy.

source: The GM Small bock
A History of the Corevtte