While the fuel side of the engine management can be readily done away with in favor of good old-fashion mechanicals, the ignition side is another story. Though it is true that a distributor can be adapted, the better solution is to retain the coil-on-plug ignition, but run it via an aftermarket stand-alone ignition control. Here D&A went with the MSD 6LS Ignition Controller, which takes input from the cam and crank sensors to operate the ignition through a fully programmable module. Andy spoke favorably of the unit: “It is a simple setup; it’s easy to play with and easy to tune. It makes setting the ignition timing fun instead of aggravating.”
This hot LQ4 combination was put through the wringer on D&A’s dyno, looking to dial in the power. On the dyno, the engine was equipped with a set of Hedman Husler headers with a primary tube diameter of 2.00 inches, and a beltdriven electric water pump arrangement. With the conservative cam duration, the engine idled good enough to be at home in a hot street machine, while the cam’s tight 108-degree lobe separation provided an impressive performance bark. The goal was to dial in the fuel and ignition settings, looking for maximum average power over the entire rpm range. The Holley 750 HP was tested against a Holley 830 carb, and interestingly the smaller carb proved to be better overall. On the other hand, the engine seemed to favor a larger 3.50-inch header collector, in comparison to a 3.00-inch piece. Tuning the ignition timing proved to be critical in getting the best from the engine, and here the MSD ignition controller excelled.
With the final dyno printouts in hand and the engine cooling on its stand, the numbers told the story. The short-cammed, big-cube stoker delivered tire-melting torque from the word “go,” showing 530-plus lb-ft right from the jump at 2,500 rpm. From there the torque just ramped upward, peaking at 581 lb-ft at just 3,200 rpm. While the low-rpm torque peak might imply that the engine would quit early, the torque just seemed to plateau, holding over 500 lb-ft all the way up to 6,000 rpm! Peak power was recorded at 588 hp at 5,800 rpm. If you are looking for wild torque, and power that keeps coming, A D&A Machine Shop stroker LQ4 will dish out the numbers.