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Ever since diesel engine work became a larger priority of Engine Builder magazine coverage a number of years ago, it’s been a goal to go visit with Dan Scheid and his team at Scheid Diesel in Terre Haute, IN. We’ve had the pleasure of speaking with a number of top diesel guys and visiting their respective shops over the years, but Scheid was always one that had escaped us – until now.
We visited the diesel engine and machine shop in Terre Haute, IN back in November to film an episode of our popular Mild vs. Wild series. While there, we took the opportunity to get the details of this $150,000, billet, triple-turbo, 6.7L Cummins engine built for Super Stock pulling. Of course, if you’re familiar with Scheid Diesel, you’ll know the shop is a huge name in both the pulling scene and in drag racing, and also hosts the Scheid Diesel Extravaganza.
Scheid Diesel was founded in 1982 with only five employees in Terre Haute. In 1990, the shop opened a second location in Effingham, IL, and nine years later, the Lafayette location opened its doors. All three locations have a fuel injection shop as well as a dedicated drive-in service area. In the more than 40 years since Scheid Diesel was founded, the shop has grown from just five employees to more than 50 employees today between the three locations.
This triple-turbo 6.7L Cummins engine represents the epitome of what Scheid Diesel’s capabilities are, so we were pumped that the engine was there for us to check out, and that we got to take a deep dive into what sorts of Scheid goodies this engine features.
“It’s a four-wheel-drive, Super Stock diesel truck,” says Joe Gasper of Scheid Diesel. “It hasn’t been campaigned yet. The chassis is done and the engine is complete, so now we need to put it in the chassis and finish the plumbing and he’ll be ready to go for the 2024 season.”
The engine was not only just completed, but it had also just been polished up and was shining bright with all that billet. The outside aesthetics aside, this 6.7L Cummins features some quality machine work and some very stout components.
“The build features one of our billet aluminum blocks,” Gasper pointed out. “We machine those in-house. It has an aluminum 1” deckplate on it. It starts life as basically a 6.7L Cummins, and then we sleeve it down to a 4.125” bore, which makes it a 6.4L. It has cross-bolted mains as well as your standard 14mm main studs in the bottom.
“The engine also features billet rods, a set of Diamond pistons, one of our steel billet cylinder heads, one of our billet injection pumps, and a set of triple turbos from Harts Diesel and Machine. The package itself should make around 3,500 horsepower. I think there’s enough turbo there to support about 4,000 hp, but we normally wastegate them down some to keep it together.”
While many applications utilize an aluminum billet cylinder head, Scheid went with a steel billet cylinder head on this Super Stock build for added strength.
“We just strictly use this for strength,” he says. “The port and everything is the same as it would be on an aluminum head. We also use one of our billet cams, Jesel roller lifters, Trend pushrods, Victory valves, PSI springs – the best of the best for a competition engine like this.”
One thing that’s hard not to notice on the Cummins build are the triple turbos, and Scheid utilized a set of turbos from Harts on this build.
“The atmosphere turbos are 4.3” inducers and the manifold or the pressure stage charger is 4.1” and it runs a substantially thicker compressor wheel as far as the blade itself to withstand all the heat and pressure from the two atmosphere turbos,” he says. “That gets fed into a SandRidge air-to-water intercooler.”
With the triple-turbo set up, this Scheid customer will normally run 150-180 lbs. of boost. However, if they really wanted to set the engine to kill mode, it could see boost pressures of 250-lbs.-plus.
To help handle some of that air going through the Cummins engine, Scheid is running an intake manifold that is an individual runner piece machined in-house out of billet. The shop also uses a Steed Speed competition manifold that they run water injection nozzles to – one per cylinder to keep the intake air temperature in the cylinder as cool as possible.
“We also have a second stage of water for backups in case EGTs rise too high,” Gasper notes. “We can kick on some extra nozzles to basically drown it out to cool it off if it gets out of hand.”
With all that air, this Cummins engine also needs the appropriate fuel. Scheid does its own injectors and fuel lines in-house.
“This engine has one of our billet injection pumps,” he says. “It starts life as a piece of billet and then uses governor weights out of your standard Bosch P8600 or P7100 pump. It’s a 16mm plunger and barrel, and it feeds through our 5/16th fuel lines into a set of 5×35 injectors done in-house as well. The injectors are a billet body and we use nozzle blanks to set them to the correct spray angle or whatever spray angle you desire, and hole size as well.”
On the front of the Cummins is a Fluidampr balancer and a taper lock setup to help in this high-horsepower application.
“A lot of the higher-horsepower people know that there’s a big problem with the vibration on the front of the crankshaft,” Gasper says. “The damper will actually rub back and forth and can fling off, so we offer a taper lock which bolts to the center of the damper. We machine the damper out and then the taper lock itself clamps down onto the snout of the crankshaft and holds everything in place.”
In addition to the aforementioned components, Scheid also uses an R&R or an Aviaid pump to supply oil, fuel and water for the water injection. Scheid also runs a separate stage of oil just strictly for the turbos, which is all driven off of the front of the crank with a belt.
While this engine is capable of 3,500-4,000 horsepower, the torque is another story. In fact, Scheid recommends that customers don’t try to pull with the engines at low rpm.
“We try to not pull them down that far just because torque is what will kill an engine,” Gasper says. “If it makes 3,500 horsepower, it makes 5,000 ft.-lbs. of torque at relatively the same rpm. We try to not pull these down below about 4,000 rpm. These will leave the line around 6,000 rpm and then it’s just spinning the tires the whole way down. It doesn’t really ever pull itself down that far.”
While this Super Stock Cummins still needs to be put in the customer’s chassis, it was awesome to see this billet triple-turbo Cummins up close, especially one that really showcases everything the team at Scheid Diesel is capable of.
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].
