Ryan Milliken's 6.8L Cummins

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If you’re an avid drag racing fan, or more specifically a diesel drag racing fan, you’ve likely heard the name Ryan Milliken thrown around before. For the last decade, the Florida native has pioneered the diesel drag racing landscape and campaigned a few incredibly fast machines that have made their way around the racing news outlets. All the while, he runs his owns business, Hardway Performance, and operates a track, Emerald Coast Dragway.

Hardway Performance is a specialty diesel performance shop that handles just about anything from stock to 3,000 horsepower builds. That's essentially how every diesel shop champions their business, but for Milliken and Hardway Performance, the proof is in the pudding. Look no farther than his two most recent diesel drag car builds that took the racing scene by storm.

A few years back, Milliken purchased Mickey Tessneer's (Mickey's Chassis Works) "Green Reaper," a ’66 Chevy Nova with a big block Chevy engine under hood. With visions of radial-tire racing in the near future, he began the planning process for a diesel engine swap. That eventually led him to Freedom Racing Engines, the diesel engine shop that would put together a beefy 6.8L Cummins engine to Milliken's standards.

Milliken campaigned the green Nova in the X275 Drag Radial racing series for a few years, and then decided a change needed to be made. The team sold the ’66 Nova and swapped in a slightly newer car, a ’69 Nova – this time in light blue. With the mantra of "don't fix what isn't broke," Milliken and the team again approached Freedom Racing Engines for the new engine build.

"Ever since I started messing around in the diesel landscape, Freedom Racing Engines and Fleece Performance have been my go-to," Milliken says. "I’ve been racing this car for about two years now and it's been treating us very well."

"Very well" might be a slight understatement, as only a week before we talked to Milliken at PRI in December 2022, the Nova set the X275 All-Time MPH Record at 183 mph at Bradenton Motorsports Park. The pass earned them a personal best ET of 4.16-seconds in the eighth mile.

Powering the Nova is another 6.8L Cummins engine from Freedom Racing Engines, this time with some newer bells and whistles to add power.

"We went through a few different builds as this car has evolved to get it to where it is now," says John Benshoof of Freedom Racing Engines. "We had to account for a lot of different things that Ryan's doing, and first thing is the weight. Weight is speed, so ultimately, we ended back up with the billet LSM 6.7L Cummins base block with a 4.250″ bore. We have a custom piston we get through Diamond, and it has our proprietary ring stack that we’ve developed, that's a huge part of the reason Ryan can beat on it and its still alive today."

The team found that with the turbo technology, tuning, and injectors available today, they could not only increase power, but there was a sort of paradigm shift where the new goal was to build the strongest and lightest engine possible to support that horsepower.

One of the most unbelievable aspects of the build is that the Nova is rocking a factory 6.7L crankshaft. On Milliken's personal best ET run, he was going through the traps at an astounding 6,300 rpm. The car weighs 3,290 lbs., and with horsepower calculations, it's making around 3,100 horsepower at the flywheel.

Benshoof mentioned that Milliken's partnership with Freedom Racing Engines is more or less a test and tune relationship with his Nova. "We’ve got Wagler connecting rods in it and a Wagler head, a Peterson dry sump oil pump, and our own custom billet dry sump pan that we designed," he says. "A lot of this right here is driving us towards our next product, which is our billet aluminum Fleece Performance engine block."

"A huge part of what has allowed me to get it to this level is S&S Diesel Motorsport and the MoTeC ECU," Milliken told us. "This MoTeC has put the car on an entirely new level as far as fine control, along with the extremely nice fuel system components from S&S."

The Nova also boasts a large, single Harts turbo that compresses air into the cylinder. It all makes for a truly unique car with an unconventional engine under its hood, and we love it.

Diesel of the Week is sponsored by AMSOIL. If you have an engine you’d like to highlight in this series, please email Engine Builder Editor Greg Jones at [email protected].