Topping their 440, JMS used the Indy SR aluminum cylinder heads that each builder was required by the rules to utilize. These heads are a great fit to the 440, offering big ports and valves, while rocker gear remains in the stock location. Starting with the CNC ported castings, the ports and chambers of the Indy heads were cleaned up in-house, then the heads were treated to a multi-angle valve job, then assembled with SI stainless steel valves and Isky PN 9375 P105 valvesprings to match the custom roller cam. T & D PN 8215 rocker arms were utilized for their strength and accuracy, and JMS had no valvetrain related issues during their dyno session. To top this combination, JMS used an Indy PN 440-14-12 aluminum single-plane intake manifold with a 4150 style flange, and topped it with a PC Carbs HP 1000 stage III four-barrel.
Having a dyno in-house was definitely an advantage for JMS Racing Engines. Their engine was ready to go right out of the box, making all its required pulls without any tuning whatsoever. In fact, it was only during the final three pulls of the session that engine builder Mike Johnson made any changes to his engine, stepping up the jets and increasing ignition timing slightly to compensate for the atmospheric differences at Comp. With these changes, their 440 made its best pull of 678.1 horsepower and 563.5 lb/ft of torque for a combined score of 1241.6, finishing fifth overall. We congratulate Mike and the crew of JMS Racing Engines on a strong finish in their inaugural Amsoil/Mopar Muscle Engine Challenge and look forward to seeing them compete in future contests.