The 2007 Jeg's Engine Masters Challenge was the forum for the recent shootout of factory-based musclecar engines, where the country's top builders duked it out for $192,000 in contingency prize money. With that kind of cash on the line, guys were going to put their best foot forward and employ every legal trick in the book.

In past years, we based the JEMC on a cubic inch limit, but that was no fun for builders, and it really didn't put things into perspective for readers more familiar with 305 Chevys, 318 Mopars, and 351 Fords. Average guy stuff. The rules for 2007 were simply to build a pump-gas musclecar engine between 302 ci and 500 ci, using the original OEM bore and stroke dimensions, plus a small margin for overbore and journal cleanup. Compression ratio was limited to 10.5:1. Components had to be commonly available aftermarket heads, intake, carb, and block, with full compatibility to the OEM components for the model year of engine built. For fun, we threw in a flat-tappet hydraulic camshaft rule because that presented a realistic limitation that the regular gearheads can emulate.

The qualifying scores were computed by taking (from three pulls) the average corrected torque and average corrected horsepower between 2,500 and 6,500 rpm, adding them together, multiplying by 1,000, then dividing by the claimed cubic inches. The score would then reflect the relative efficiency per cubic inch of each engine, thus leveling the playing field and removing the advantage of larger displacement motors.

What follows is the breakdown of each engine in competition, its qualifying score, OEM engine size, claimed displacement, and the best dyno sheet from the three pulls made during official qualifying. We've also included the important engine specs for your reference. Yes, we know there are gaping holes in the selection of engines (where's the 426 Hemi, the Mopar big-block 383 and 440 Wedge, the 302 Windsor, and the Boss 429-to name a few?). But when push came to shove, these were the engines our competitors elected to build, based on their perceived competitive advantage. Let's crank up the dyno!

BES Racing Engines
400 Small-block Chevy
Claimed displacement: 403 CI
Qualifying score: 2,461.1

Team leader: Tony Bischoff
Team members: Brad Nagel, Richard Kolb,
Brett Vonder Meulen
Hometown: Guilford, IN
Bore: 4.125 inch
Stroke: 3.763 inch
Compression ratio: 10.4:1
Carburetor: Holley 1050 Dominator
Carb spacer: HVH four-hole transition
Intake: Dart
Cylinder heads: Racer Pro
Block: World Products
Intake valve: 2.19 inch
Exhaust valve: 1.60 inch
Camshaft specs: COMP; 252/259 degrees
@ .050, .690/.690-inch lift
Rocker arms: Jesel, 1.9:1 int., 1.8:1 exh.
Crankshaft: Eagle, forged
Rods: Eagle, 5.700-inch
Pistons: Ross, forged
Rings: Speed-Pro
Ignition: I.C.E.
Oil: Royal Purple 5W-30
Headers: Kooks, 1 3/4-inch
Mufflers: MagnaFlow

DTS Dyno Data
Best Qualifying Pull

RPM TQ HP
2,500 474 226
2,600 477 236
2,700 481 247
2,800 489 261
2,900 493 272
3,000 495 283
3,100 495 292
3,200 496 302
3,300 494 311
3,400 490 317
3,500 485 323
3,600 484 332
3,700 489 344
3,800 494 357
3,900 498 370
4,000 504 384
4,100 510 398
4,200 518 414
4,300 527 431
4,400 535 448
4,500 545 467
4,600 555 486
4,700 565 505
4,800 573 523
4,900 578 539
5,000 580 552
5,100 581 564
5,200 578 573
5,300 578 584
5,400 579 595
5,500 578 605
5,600 578 616
5,700 577 626
5,800 575 635
5,900 570 640
6,000 565 645
6,100 561 651
6,200 558 658
6,300 553 663
6,400 548 668
6,500 544 673