The Four-Valve Swap Power Struggle Upgrade Part 2

Extra Ribs, Please
Our supercharged steed utilizes none other than the Vortech T-Trim centrifugal supercharger, and a call to Vortech provided us with everything we needed for the conversion from Two-Valve motor to Four-Valve. Everything supplied by Vortech would have fallen in place, except that we wanted to use an eight-rib drivebelt system. Vortech does not offer a kit to accomplish this on our particular vehicle, but it did supply spacers and several components used for the eight-rib setups that are offered on other modular motors.

With this eight-rib setup, we did encounter some clearance problems. First, when the blower was spaced out appropriately to align its drive pulley with the wider belt, the drive pulley contacted the front of the reused Bullitt/Cobra alternator. We eliminated that with some minor grinding of the front of the alternator. Shortly thereafter, we discovered the coolant crossover tube wouldn't pass in front of the wider eight-rib alternator pulley. We took the crossover tube to Tracy Grimm at Speedfab, who extended the forward-facing tubes so the crossover tube would clear the front of the pulley.

The custom eight-rib system didn't stop there at giving us grief. When we tried to install the supercharger intake elbow, we found that it contacted the radiator before it completed its turn toward the fender. Again, this is no fault of Vortech, but it was caused by the supercharger having to be spaced forward to accommodate our custom eight-rib setup, in addition to the car having a thicker aftermarket radiator. To gain the needed clearance, we relieved the upper flange on the radiator. The T-Trim is now snuggled in and ready to bolt up to it's partner-in-horsepower crime, the Vortech aftercooler.

Although the Vortech engineers warned us the aftercooler we had on the Two-Valve would be restrictive at the power levels we were hoping to produce, we wanted to stick with it initially to best evaluate the gains of the Four-Valve motor upgrade itself. Last month we showed the inlet and outlet modifications done to convert the cooler from its Bullitt configuration to a Mach 1 inlet and '01 Cobra outlet. We also had the staff at Speedfab weld the fitting to mount Vortech's mini Race bypass valve, as we needed to upgrade from the base valve.

Now finished with our tasks in the engine compartment, a twist of the key brought the Four-Valve Bullitt Mustang to life. Next month, we're going to wrap up this quad-cam chaos with tuning, dyno testing, and track blasting. Check back to see how it all cammed out.