Dyno Testing A Home-Built Pontiac Motor - Backyard-Built Bruiser

Removal of the Strelka-Built valve covers reveals the KRE rocker stud girdle, which adds high rpm stability to the valvetrain.

These Competition Products springs feature a seat pressure of 220 lbs and an open pressure of 600 lbs at 1.875-inch installed height. They are Electro-polished to remove stress risers in the metal surface that can weaken the spring prematurely. The rocker studs are from ARP, the rocker arms are Harland Sharp 1.65:1 rollers, and the pushrods are JBP custom pieces.

Removal of the KRE valley pan reveals the SD Performance Mega Brace that keeps the lifter bores in one piece.

A look into the intake ports offers clues as to the port work that was performed by SD Performance. Full race porting increased the port volume to 230ccs from 215. Of course, the intake and heads were gasket matched as well.

Lifting the Edelbrock heads exposes the ARP studs and the Fel-Pro gasket with stainless steel sealing rings. The studs aid in keeping the cylinder pressure where it belongs.

Here you can see quite a bit of SD's handiwork. Note how the chamber is now a heart shape to promote swirl, improve combustion and ward off detonation. According to SD Performance, the efficiency of the chamber allows for 2-degrees less timing. The valves are large 2.19 intakes with 1.77 exhausts. Cygan says, "The intake valve is actually big for this combo and is shrouded more with the 4.190 bore than we would like to see, but we did it because we may run an IA II block in the future. This way we don't have to redo the heads." Chamber size has also been reduced to 64 ccs to increase compression. Dave related that regardless of any shrouding, the big intake valve will still make more power, even with the relatively small bore, than the 2.11-inch intake.

Ross custom-forged pistons feature 23ccs worth of valve reliefs and dish. When used with the 64 cc chambers, the resulting static compression ratio is 11:1. Thanks to the heat dissipation properties of the aluminum and the more efficient chambers, this is a pump gas engine.

With the engine on a stand and flipped over, the stock oil pan was removed. Gary showed his handiwork by installing a trap door and baffle to keep the oil at the pickup in high g situations.

Gary chose to employ a full-length windage tray with this engine so he made sure his oil pan mods did not interfere with the tray.

With the tray out of the way, a rod and piston were removed to be photographed. Here you can see how Gary slightly dressed the already-chamfered oil holes on the Eagle crank.

The Eagle H-beam 6.800-inch forged steel rod features ARP bolts. It also has the necessary 2.200-inch big end to fit the journals. Stock Pontiac cranks have 2.250-inch rod journals.