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331CI Chevy Small-Block Engine - Horsepower

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331CI SMALL-BLOCK CHEVY, 486 HP at 6,900 RPM

Jeff Latimer, Valencia, CAThere are certain engine combinations that just work. In the history of the small-block Chevy, the little 327 has been passed over in the rush to Mouse motors of larger and larger displacement. But Jeff Latimer hasn't forgotten. He works at one of our favorite machine shop haunts, Jim Grubbs Motorsports, and has built a series of small-displacement, high-revving street small-blocks mostly just because he likes them. His latest adventure is this 0.030-over 327 that will eventually find a home in his meticulously detailed '63 Chevy II. Combine a 4.030-inch bore with a short 3.25-inch stroke crank with good heads and a big cam and you can expect this motor to rev-6,900 rpm to be exact. But Jeff planned it that way. He expected it to do well, but not as well as the 486 hp this little spinner actually produced. Better yet, it makes peak torque at 4,900, which gives this mini-Mouse a 2,000-rpm powerband spread between peak torque and peak horsepower. If all that isn't enough, this equates to 1.47 hp/ci. Listen closely and you can just imagine the sound of this tight small-block powershifting through all three gear changes.

DYNO CHART
RPM TQ HP
3,500 357 238
3,700 351 247
3,900 342 254
4,100 330 257
4,300 343 281
4,500 374 320
4,700 383 343
4,900 392 366
5,100 418 406
5,300 415 419
5,500 409 428
5,700 408 443
5,900 402 452
6,100 399 464
6,300 395 473
6,500 390 483
6,700 379 484
6,900 367 482
Peak HP: 486 @ 6,600
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