I didn't know much about Pontiac's '303' engine, so I had to do some digging. I was curious about the bore/stroke relationship.. and for us 'over square' engine lovers (who love revs), all I can say is WOW...
Does anyone have an audio clip of this engine at 8-9 grand??
Has any factory engine ever had a higher bore/stroke ratio than 4.125/2.84= 1.45
The 303's bore was identical to the 400 at 4.125 inches, but it featured a shorter stroke at 2.84 inches. The 303's short deck took off about 40 lbs. from the 400 V-8 version. The racing 303 was equipped with four-bolt mains, a forged steel crankshaft, aluminum intake and a high-rpm crankshaft that allowed the engine to rev up to a whopping 8,000 revolutions per minute. Pontiac beefed up the main-bearing webbing to handle the high revs and reinforced the ribbing. The engine was a Ram Air forced induction model with Ram Air V heads and R/A-V cast-iron exhaust manifolds. The compression ratio was set at 10.75-to-1, and with an 800 cfm four-barrel Holley carburetor, it generated up to 525 horsepower. The intended production version, which would satisfy the SCCA homologation rules, would generate 355 horsepower.
« Last Edit: March 06, 2014, 05:39:55 PM by 69Z28-RS »
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