The Amsoil/Mopar Muscle Engine Challenge - JD Engine And Machine

All the competitors this year had to use the same Indy SR cylinder head and could order either the CNC ported or the non-ported version from Indy. JD Engine and Machine chose the CNC ported versions to top their 440, and engine builder Jeff Dickey treated them to some hand-massaging to optimize flow. Using the Indy valves, Jeff installed Comp PN 947-16 valvesprings with titanium retainers to handle the lift exerted by the Comp solid roller camshaft. Harland Sharp rockers with a lift-enhancing 1.7 ratio were utilized for their proven durability. Rather than concentrating on a single horsepower here or there by reducing windage, Jeff says he spent most of his time maximizing cylinder head flow for the most power potential. This theory worked well as his second place engine nearly missed winning the contest, and was well ahead of the third place entry.

When it came to induction, Jeff tested several intake manifolds before deciding to use an Edelbrock Super Victor single-plane intake with a Dominator flange. Knowing this engine would likely end up in a street car or bracket racer, Jeff resisted the urge to attempt maximum power by using a tunnel-ram, instead deciding to keep it simple given the intended use of this engine. Topping his Super Victor intake, Jeff used a Holley Dominator prepped by BRE. While we can't speculate as to how this engine would have performed with a tunnel-ram, we can say that any improvement in this engine's performance would have certainly made the first place choice more interesting.