Dyno Time

The engine was completed with an Edelbrock mechanical water pump and fitted with a set of Schoenfeld 1¾-1⅞-inch step headers and it was off to meet the SuperFlow/DTS Powermark dyno at the 2012 AMSOIL Engine Masters Challenge hosted at the University of Northwestern Ohio. In discussing this engine with Henderson what got our attention was the broad appeal of such a popular engine combination. It doesn't get much more mainstream than a production-based 406 small-block with 23-degree heads and a hydraulic roller cam, however, watching the engine perform on the dyno showed that the output was anything but common for this kind of arrangement. Henderson's Chevy easily surpassed the 600hp mark, topping out at an impressive 612 hp at 6,300 rpm. In terms of engine speed at peak power, the build was right on target for our competition's 6,500-rpm limit. Delivering 546 lb-ft of torque at 5,400 rpm, there was a peak of 1.34 lb-ft per cubic inch developed, an outstanding accomplishment.

This small-block Chevy from Henderson Power Sports proves that it doesn't take the trick of the week or a reinvention of the small-block to produce impressive results. Careful planning, machining, and assembly, as well as selecting effective components will deliver the goods. No doubt this is one of the main reasons the popularity of Chevy's original small-block continues to endure.

BY THE NUMBERS
406 Chevrolet Small-Block
Bore: 4.155 inches
Stroke: 3.750 inches
Displacement 406 ci
Compression ratio: 10.5:1
Camshaft: custom COMP hydraulic roller
Valve lift: .725/.734 inch
Rocker and ratio: COMP 1.7:1
Piston rings: Total Seal 1.5/1.5/3mm
Piston: CP forged
Block: OEM production Chevy 400
Crankshaft: Scat
Rods: Eagle 6.00 inches
Cylinder head: AFR 235
Intake valve diameter: 2.125 inches
Exhaust valve diameter: 1.600 inches
Intake manifold: Edelbrock Victor
EFI: ACCEL DFI
Header: Schoenfeld 1¾-1⅞-inch step
Ignition: ACCEL DFI
Damper: Innovators West
Fuel: VP Fuels VP100
Oil: AMSOIL 5W20 synthetic

ON THE DYNO
406ci Chevrolet
RPM TQ HP
2,500 436 208
2,700 448 230
2,900 444 245
3,100 449 265
3,300 467 293
3,500 478 319
3,700 489 344
3,900 496 358
4,100 505 394
4,300 509 417
4,500 515 441
4,700 524 469
4,900 533 498
5,100 541 525
5,300 545 550
5,400 546 561
5,500 545 571
5,700 544 580
5,900 533 599
6,100 524 608
6,300 510 612
6,500 493 610

SOURCE
Henderson Power Sport
North Ridgeville
OH  44039
216-401-7231
http://www.hendersonpowersports.
com/