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Chevy Small Block Part 22 - PT. 22: Horsepower Is King!

The Right Combinations Are The Key

By Mike Petralia

Speed-O also installed the biggest cam we had run up until that point, a Crane Cams hydraulic roller with plenty of lift and duration to make the power we were looking for. And then they topped it off with an ACCEL GEN VII DFI fuel injection system to give it the utmost in tunability. At the time, Speed-O had not finished their engine dyno cell yet, so we trucked the engine back to Vrbancic Brother's Racing and once-again bolted it onto their DTS engine dyno for a days worth of blowin' in some power!

In order for the boosted power increase we got to mean anything to you, we first left the blower belt and induction plumbing off so we could test it without any boost (see T31). Then we hooked the blower up and spent the rest of the day searching for power. And boy did we get some! Max 697 hp and 613 ft-lb of torque, all on pump gas (see T32). But, there was a problem, which we only found when we tore the motor back down after the tests. The Fel-Pro PN1003 head gaskets we used were never meant to hold back the kind of boost we were running (almost 15 psi) and they literally began to push themselves right out of the engine (see photos). If we were to do this again, we'd simply install a set of new Multi-Layer-Steel (MLS) head gaskets that can hold back much more pressure.

DM Part 18-Test 31:
355 cid, 9.1:1 cr, 4.030-bore 4-bolt Motown block, 3.48-stroke Lunati crank, 5.7-inch Lunati steel rods, TFS aluminum heads (Summit Racing PN TFS-30400013-CNC, 72cc chambers, 195cc runners, 2.02/1.60 valves). Accel Gen VII DFI with 55 lb-hr injectors and Dual Sync Accel computerized distributor. Crane Cams hydraulic roller camshaft (PN 119681, 306 intake / 314 exhaust advertised duration; 240/248 @ .050; .595/.595 lift, 114 lobe separation). Crane retrofit hydraulic roller lifters, Crane pushrods, and COMP Cams 1.6:1 rockers.

DM Part 18-Test 32:
Installed Procharger D-1SC centrifugal supercharger with 4.25-inch pulley.

Test 31 Test 32
Motor Blower Boost
RPM TQ HP TQ HP (PSI)
2600 316 156 388 192 2.5
2800 346 184 415 221 2.9
3000 364 208 439 251 3.2
3200 384 230 462 282 3.9
3400 384 248 482 312 4.4
3600 385 264 500 343 5.0
3800 383 277 520 377 5.4
4000 388 395 545 415 5.8
4200 398 319 568 454 6.5
4400 404 338 583 489 7.4
4600 405 355 597 523 8.1
4800 411 375 609 557 8.9
5000 420 399 611 582 9.7
5200 424 419 607 601 10.4
5400 423 436 612 629 11.3
5600 419 447 613 653 12.2
5800 413 456 613 677 13.0
6000 405 462 606 692 13.8
6200 395 466 591 697 14.7
Max 424 466 613 697 14.7
Avg 393 333 545 471 7.8
By Mike Petralia
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