Be it freestyle competition, car crushing, or crossing lakes, Brandon Overmyer’s diesel anomaly is stirring things up in the world of monster trucks.
Although they’ve seen success from time-to-time in the monster truck world, diesel-powered versions have always been few and far between. If you campaign an oil-burner in this form of motorsport, you’re basically alone on an island. It just so happens that that doesn’t bother Brandon Overmyer. After the Indiana native traded in his sled pulling hobby for monster trucking, he brought his Cummins—and all the diesel know-how that comes along with it—with him. “As a diesel guy, I didn’t want to run a blown alcohol engine,” Brandon tells us. That choice would gift him a proven, 1,000hp recipe right out of the gate.
Surprisingly, prior to buying his tube-chassis monster, Brandon was on the hunt for the leaf spring, 4×4 pickup his parents used to haul him around in as a kid. But when the deal to buy it back fell through, he decided to go all-in on the monster truck idea. Now, his Cummins-powered ’69 Dodge is a hit everywhere it goes. Maybe it’s the unique sound. Maybe it’s the plumes of black smoke. Or maybe it’s because fans can relate to it. “People can connect with a diesel,” Brandon explains. “There aren’t many blown alky engines running around on the street, but there are all kinds of diesels on the street.”
The truck is called American Outlaw, and this is its story.
The Chassis, The Body, And The Truck’s Identity
When Brandon got his hands on the truck, it was in rolling chassis form. Formerly owned by Paul Wickleman of Phantom Motorsports, a man that had acquired more than a dozen monster trucks over the years, Brandon could tell the chassis was done right and ready to go to work. The ’69 Dodge Sweptline body came from GTS Fiberglass & Design with Hoffman Body Shop & Graphics of Akron, Indiana handling the vinyl wrap job. The eye-catching graphic present on the doors came from the creative mind of a monster truck fan named Taylor. Even more so than the Cummins power plant, it represents the truck’s identity.
B-Series On A Budget
Applying what he knew from the truck pulling world—namely how to make a budget-built 12-valve Cummins live at four-digit horsepower—Brandon dropped the P-pumped 5.9L into place behind the cab. The cast-iron B-series sports a girdle and ARP main studs, shot-peened factory forged-steel rods, 13:1 compression pistons, a fire-ringed head that’s surprisingly more stock than you’d ever guess, and ARP head studs. Dual early 1980s Mustang radiators from Summit Racing and a pair of eBay-scored electric fans are onboard for engine cooling, and the addition of a Fleece Performance Engineering coolant bypass system ended any chance of the Cummins ever overheating.
Sled Pulling Parts
The 13mm P7100 bolted to the Cummins’ front cover says Brandon is serious about making horsepower. Fitted with an auto governor, a quick-rate cam, and thanks to being timed with 28-degrees of advancement, the healthy P-pump allows for ether-free cold-starts and brisk turbo response. Another piece from Brandon’s old pulling engine are the 5x.025 injectors sitting downwind of the P-pump. After picking up 150hp over the competition’s injectors back in the day, Brandon swears by the Hart’s Diesel units. An A1000 lift pump, in conjunction with an Aeromotive adjustable pressure regulator, supplies the P7100 with 60-psi worth of Haisley and Schaeffer-treated fuel.
Big Single And Air-To-Water Intercooling
Boost comes courtesy of Brandon’s friends at Stainless Diesel. The single BorgWarner S400 boasts one of the company’s billet, 5-blade compressor wheels—this one with an inducer that measures 75mm. An 87mm turbine wheel resides within the T4-foot exhaust housing that bolts to a flipped, stock replacement manifold (also from Stainless Diesel). An external TurboSmart wastegate is present to bleed off excess drive pressure and will come in very handy should Brandon ever activate the nitrous system. To ensure intake air temps stay reasonable, an old-school PT2000 air-to-water intercooler from Precision Turbo & Engine is employed. And because ice won’t last for the duration of a freestyle performance, Brandon simply runs ambient temp water in the icebox.
Fortifying The Weakest Link
In a 14,000-pound vehicle that catches air and makes use of a big single turbo, transmission durability and efficiency are key, and the 47RE automatic in American Outlaw delivers. Built by Landis Transmission And Automotive Repair, the all-billet shaft four-speed boasts Sun Coast’s stubby shaft kit and TH400 slip yoke arrangement, a Goerend Transmission constant-pressure valve body, and a Goerend extreme clutch, triple-disc converter. The 3,000-rpm stall, billet stator and front cover converter complements the S475 perfectly and, in an effort to limit potential breakage, spends very little time in lock up. A Firepunk Diesel Anteater module is used to control all of the 47RE’s shift points and a Profab Machine quick change transfer case (i.e. drop box) routes power to the axles.
Clark Axles And PEI Shocks
Proven, familiar Clark planetary, hydraulically steered, axles can be found under the truck, front and rear (these being 22-ton versions), and Brandon runs 12-inch rotor, Wilwood pinion brakes to bring the 7-ton behemoth to a stop. The truck’s nitrogen-filled Patrick Enterprises, Inc. (PEI) shocks are also a common sight in the monster truck world, and the 26-inch units are never over-extended thanks to the Nylon limiting straps you see here. If you look closely you can also spot the aforementioned quick change transfer case from Profab Machine, which provides a 12-inch drop between input and output shafts.
66-Inch Firestones
And now for the quintessential monster truck visual: 66-inch rubber. The 66-inch overall diameter Firestone tires under American Outlaw feature a 43-inch section width and accommodate 25-inch wheels (hence their 66×43.00-25 designation). The 23* present on the sidewall means these particular flotation tires have 23-degree tread bars, which is said to be an advantageous pitch for effectively applying power to the ground. The full-cleat tires you see here are aboard the truck when it’s on display, while a shaved down set get the nod during competition.
Record-Setting Float Trip
Over the summer, Brandon and his crew put triple 66-inch (front and rear) tires on the truck and proceeded to float across a local lake. The triple-tire arrangement was a monster truck first, and at 27-feet, 4-inches wide American Outlaw also became the world’s widest monster truck. The total overall weight in tires alone tipped the scales at 13,000 pounds. You can check out the feat for yourself on Brandon’s “Merica-Tv” YouTube page right here. Brandon’s inspiration for the lake drive came from the 1986 hit “Return of the Monster Trucks.”
High Flying, From Spring ‘Til Fall
As part of its regularly scheduled programming, American Outlaw catches air—major air. Freestyle, car crushing, and booth display were all part of the truck’s appearances this summer, and Brandon tells us 2024 will be filled with more of the same. Of course, living up to his own words that the truck will “never be complete,” a freshly rebuilt Cummins will be in place come next season, as well as a few other choice upgrades. Next year, you’ll be able to find American Outlaw in action around the greater Indiana area from May until fall. It’ll be the one that whistles and throws plumes of black smoke skyward.
Aptly Named
When Brandon runs out of cars to crush and lakes to cross, he has no qualms about kicking his 14,000-pound Dodge sideways for the camera. “I don’t care if they kick me out,” he told us after parking the truck. “I’m ready to go home anyway.” Brandon’s Cummins-powered Sweptline says American Outlaw on the door for a reason… He means it!
