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Edge, along with Diesel Dynamics, built three engines for test and development purposes. All are based on the Cummins 5.9-liter inline-6 but only the engine blocks are original equipment. Custom crankshaft and rods were sourced out but Lehman won’t disclose stroke or rod length. Custom pistons that “are not flat top” complete the rotating assembly. The cylinder heads—especially the valves—received major work to open up air flow. Edge also had custom camshafts ground to their specs. Currently stock injectors are used but Lehman says, “We feel there’s more potential with something else.” The injectors are driven by instructions from an Edge-calibrated engine management computer.

Twin turbos from Diesel Dynamics force-feed air to the cylinders to keep up with the extra fuel, according to driver Keith Lockliear. “We stuff a bunch of fuel to the engine, figure out how to feed it even more fuel, then play with the turbo and boost till we get what we call ‘mega mental’ amounts of air and boost to burn all that fuel.”

The diesel is backed by a Lenco 5-speed and special clutch setup. A typical Pro Stock car will launch at about 8000 rpm while the diesel redlines between 4000 and 5000 rpm. But it offers a ton of twisting power that can be difficult to tame. In fact, nitrous oxide is mixed with the Chevron #2 diesel fuel to spool up the turbos on the starting line.

“Nobody has unleashed this much violence and torque at the starting line. We’re easily running 50 pounds of boost at the start,” explains Lehman. “When you let go all at once, the massive torque has an effect on all the components. One of those things to slip was the turbo rotating on the flange.”

Although Lehman won’t be specific on any engine technology at this point, he estimates horsepower at over 1100 and torque at 2500-plus lb-ft. He acknowledges exhaust gas temperatures hover around 1450 degrees.

At this writing in late September, the truck had yet made a full pass under power. Edge is wandering in uncharted territory when it comes to clutch and chassis setup with the diesel engine. So far the truck had a best of 9.77 seconds when shutting off at the eighth-mile marker, but the team has notched a 60-foot time of 1.22 seconds. More tests were planned, including full passes, in October, and the truck is expected to appear at the SEMA show in November where more details will be released on the engine technology.

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