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Diesel of the Week

Kingspeed 6.7L Cummins

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Chase Lunsford and Michael Cordova first met while in college, competing in diesel drag races. What started as two racers trying to one-up one another on the track, quickly turned into a business partnership and a company known as Kingspeed Race & Repair in Bowling Green, KY.

“Michael was always kind of the quiet guy who would show up and kick everybody’s butt and leave,” says Chase Lunsford. “Nobody knew who he was. I had to know more about him and we started working together on a couple things.”

Michael and Chase’s drag racing hobby began to transition to full-time work when Michael helped Chase with his Pro Street truck. The diesel duo opened Kingspeed in January 2016.

“That’s when we went into business and bought the equipment to actually do it ourselves rather than borrowing other people’s equipment,” Lunsford says. “We had people approaching us to do things on the side and my wife had a big industry move, which meant she needed to end up in Bowling Green, KY where her family’s business is.


“I felt Bowling Green was a great place for what we do. I knew that it would probably take a little bit to get where we wanted to be, but I figured we should jump with both feet. Our interests have evolved a little bit over the years, but it’s been an incredible experience for sure.”

Today, Kingspeed is a full-service repair and maintenance shop as well as a full-service machine shop focused on both diesel and gas engines. With seven full-time employees and 6,250 sq.-ft. of space, Kingspeed is capable doing just about everything in-house. Kingspeed also does performance engine work and machines custom, billet aluminum parts.

“We have two mechanics who are full time,” he says. “They stay busy 40-50 hours a week doing the repair, maintenance and performance work that comes in the shop. We have a four-axis CNC mill, a seat and guide machine, a cylinder hone, etc. We have an engineer on staff. We’ve got a welder and fabricator on staff full-time and then Michael and myself wear a bunch of hats.”

On the performance side, Kingspeed focuses primarily on Cummins engines, but will work on Powerstroke and Duramax engines on the repair side. The shop also does work on Ford’s Coyote 5.0L engine as well as Gen V LTs and LS engines.

“That’s where we’re just a little bit different than most diesel places,” Lunsford says. “We sleeve all the blocks here. We bore them and do all the girdle modifications here. On the parts side, we’re known for oil pans and transmission pans for Ford, Chevy and Dodge. On the Cummins stuff, we focus on billet intake manifolds, billet valve covers, fuel pump block off plates, gear cases, adapter housings, etc. The Cummins stuff is what we’re into and what we’ve always been into.”

The Bowling Green, KY shop has come a long way in just four years and change, but Chase and Michael aren’t resting on their laurels.

“We’re really focusing on retail and trying to get our aluminum fabricated parts out there that compliment engines,” Lunsford says. “We need a whole bunch more equipment if we really want to be a Sonny’s or a Pro Line or a real hardcore engine shop. Right now, we have enough to be really dangerous.”

Proving just how dangerous Kingspeed can be is their build of a turbocharged 6.7L Cummins for an early customer by the name of JP Libert.

“JP has been around since the beginning of Kingspeed,” he says. “He took a liking for what we wanted to accomplish.”

JP had built out a chassis that, according to Chase, is probably one of the lightest four-wheel-drive chassis out there. His truck is named Gray Area and JP came to Kingspeed wanting to do an engine build for it.

“We basically took the same recipe that I had in my first street truck and made a couple tweaks,” he says. “It is a 6.7L Cummins block that has our girdle kit. It is a .040˝ over 5.9 bore, so a 4.060˝ bore with a 6.7L crank. It’s a really solid platform. It’s a roller cam set up that we did for him, which was ground by No Limit Manufacturing. It’s got a bunch of lift on the roller cam set up and it’s a higher compression. We run 20:1 compression on the single turbo stuff. It seems to make a lot more boom when you’re not relying on 150-lbs. of boost.”

Kingspeed built JP the 6.7L Cummins a couple years ago and since then, JP has really taken the time to dial the engine in.

“We refresh it every winter,” Lunsford says. “We’ve done that twice now. The engine keeps trucking. He has pretty much all the bells and whistles that we offer. He’s got our high volume, high capacity oil pan, our billet parts, our valve cover. He has a high-volume oil pump that we did for him. It has a single turbo with lots of nitrous and a good, solid fueling set up.”

In addition, the 6.7L features Diamond pistons, ARP 14mm main studs, billet rods, Dynomite Diesel Super Mental injectors, a fire ringed cylinder head, 1mm oversized valves, Kingspeed dual springs, Mahle H-series bearings, a Fleece twin CP3 kit with two Power Flow 750 pumps, a Waterman gear-driven lift pump, and a Kingspeed billet intake plenum.

“JP’s truck is a 2006 Dodge 2500,” Lunsford says. “It has a full custom chassis by Dow Brothers Race Cars and it has a Loganbuilt transmission. He uses it for drag racing and is focused on 1/8th mile and grudge racing. This 6.7L Cummins set up makes 2,000 crank horsepower, no problem!”

Diesel of the Week is sponsored by AMSOIL.

If you have an engine you would like to highlight in this series, please email Engine Builder magazine’s Editor, Greg Jones at [email protected]

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