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The Royalty family knows the diesel industry like the back of their hand. Steve Royalty, his father Merit, and son Tyler of Warren County Diesel have been engrossed in diesel motorsports for years.
Steve first got into bracket racing in 1997 in the Super Pro delay-box competition, before moving up to dragster level racing and eventually into the Outlaw Diesel Super Series. Before him, Merit Royalty was a top contender in the 5,000-lb. and 7,000-lb. Modified sled-pulling classes back in the ‘70s and ‘80s. Over five decades, the family has made a formidable name for themselves in the competitive diesel scene.
During the week, Warren County Diesel provides a variety of automotive and fleet repair services in Franklin, OH. The shop uses high-tech diagnostic equipment and employs certified, expert auto service and repair technicians who have years of experience performing everything from oil changes to a complete engine overhaul. The Royalty family has owned the shop for more than 40 years.
On the weekends, the team goes straight to the track to race their drag truck, which was a three-year project taken on by the family. The monster build has gained a load of attention in the past few years, not only for its hyper-fast drag times, but for its comically on-the-nose name and one-of-a-kind appearance that is sure to evoke a few double takes.
“Climate Change,” the truck in question, is a 2000 model body Dodge Dakota Pro-Mod truck powered by a mechanically injected triple-turbo 6.7L Cummins engine that belts out upwards of 2,500 horsepower, more than 3,000 lb.-ft. of torque, and an even crazier amount of smoke.
Behind the steering wheel is Steve, who races the truck in the ODSS Pro Mod class, local Quick 16 races and No Prep races.
Despite challenges along the way and a heap of broken parts, Royalty’s Climate Change is capable of running times like a 4.54 at 162 mph in the 1/8th-mile, which definitely gets him noticed by the masses. He was even contacted by the producers of Street Outlaws and will hopefully be seen racing on your TV screen soon.
“Our ultimate goal is to get into the 3s in the 1/8th-mile at around 200 mph and have one of the fastest diesel trucks on Earth,” Royalty says. “We’ll get there eventually.”
Of course, with any powerful machine, a master builder stands behind it. This billet aluminum block 6.7L Cummins engine was built by Scheid Diesel and features several creative upgrades that work to launch the truck down the drag strip such as a Scheid modified Cummins crankshaft, Diamond pistons and R&R/Scheid Diesel connecting rods. The mill is bored .030” over, which makes the engine 401 cubic inches and technically a 6.9L with a 14.2:1 compression ratio.
The valvetrain features a Scheid/COMP solid roller camshaft with Cook and Sons valvetrain components, titanium intake valves and Inconel exhaust valves in a cast steel cylinder head. The engine has been blueprinted hundreds of times in order to make a bulletproof build.
The air and fuel setups are arguably the most head-turning parts of the build. The triple turbochargers are setup in a unique way, with two Forced Inductions 82mm atmospheric turbos feeding into a larger, custom 105mm turbo that is perched right next to Royalty in the cockpit. This would be illegal in the NHRA, but not for ODSS. With the 170 lbs. of boost being produced, engine stability has always been a priority in the build.
“It’s taken a lot of testing and trial and error due to the horsepower and torque of this thing,” Royalty says. “It’s not particularly light either. At 3,300 lbs. it’s relatively heavy for what it is.”
A ballistic blanket and scatter shield in the cockpit serve as safety measures, yet it’s still dangerous. Currently, Royalty is working to move the third turbo to a different location and replacing it with a 114mm Harts turbo.
“We’re in the process of relocating the bigger turbo, it’s going to be centered up directly above the rear axle and then our chargers are going to be moved back and down. It’s going to make it safer and a little bit lighter by distributing some more weight to the back. We’re also going to be taking the wing off the cab.”
A DSR gear-driven fuel pump feeds a 14mm injection pump, which then delivers the high-pressure fuel through Scheid triple-feed injectors to the custom fabricated intake manifold. A nitrous oxide and water-methanol combination injection keep the temperatures in check. The engine also features a Jones Racing dry sump oil pump and custom dry sump pan and tank.
The Royalty family’s build is ongoing, as Steve and the gang are always looking for ways to improve their times and get closer to building the “fastest diesel truck on Earth.” Their legacy in diesel racing and pulling will no doubt continue on for years.
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].
