The Air Flow Research 210cc CNC cylinder heads were polished before assembly. A Moroso stud girdle ties all the Harland Sharp 1.6:1 rocker arms together for stiffness. The Air Flow Research 210cc CNC cylinder heads were polished before assembly. A Moroso stu More PowerWith the high torque testing out of the way, Lirones wanted to give the engine an extra boost in power but didn't want to sacrifice too much of its peak torque. They were, however, willing to move the torque peak up in the powerband, in order to make more top-end horsepower. Lirones swapped on Arizona Speed & Marine's modified Dart single-plane intake manifold with larger 36-lb-hr injectors and a 1,000-cfm four-bbl-type throttle body. Since the TPI system was controlled by the still effective, yet older ACCEL Gen VI ECU, Westech suggested that the new EFI system might be a bit more tunable using a new F.A.S.T. ECU. With the new manifold, injectors, and throttle body bolted on and the F.A.S.T. ECU plugged in this new package was worth a huge gain in top-end power. And all that peak torque that really brought the 406 to life was not sacrificed that much. After all testing was completed, it wasn't hard for the engine's owner to choose the more powerful F.A.S.T. ECU/single-four barrel EFI system because he likes power. But we wanted to show you both systems' test results because it turned out that the TPI setup would make a killer everyday street motor. Cams has developed its Endur-X solid roller lifter line for everyday street use. This oil groove machined into the lifter body provides pressurized oil to the cam lobes, which is critical, especially at low engine speeds. Cams has developed its Endur-X solid roller lifter line for everyday street use. This oil 406-CID EFI MOTOR SPECS Bore x stroke: 4.155 x 3.75 = 406 cid Compression: 10.4:1 JE forged pistons Crank: Cola 4340 forging Rods: Oliver 4340 steel 5.7-inch Rings: Speed Pro moly Bearings: Clevite Oil system: Melling pump, Canton pan Fasteners: ARP Heads: AFR 210cc CNC Induction: Arizona Speed & Marine EFI ECUs tested: ACCEL and F.A.S.T. Ignition: MSD with Champion plugs Gaskets: Fel-Pro Cam: COMP Cams, solid roller 236/243 duration, .552-lift, 112 LS Dampener: Fluidampr The bottom end has to be strong to survive, and Lirones spared nothing here. The Cola crank and Oliver rods ensure ultimate reliability while the four-bolt GMPP Bow-Tie block ties it all together for the best rigidity. The bottom end has to be strong to survive, and Lirones spared nothing here. The Cola cran 406-CID EFI DYNO POWER AND TORQUE TORQUE MONSTER With modified TPI manifold, ACCEL ECU, two-bbl throttle body, and 32 lb-hr injectors RPM TQ HP 3,000 492 281 3,200 487 297 3,400 489 317 3,600 488 334 3,800 485 351 4,000 484 368 4,200 481 385 4,400 477 399 4,600 468 410 4,800 454 415 5,000 437 416 5,200 418 414 5,400 398 410 5,600 375 399 AVG: 479 359 MAX TQ: 492 @ 3,000 MAX HP: 416 @ 5,000 « | 1 | 2 | 3 | » | View Full Article By Mike Petralia Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!