Twin Engine Terror: A Pickup with Double 5.9L Cummins

Is this Double 5.9L Cummins Pickup the World’s First?

“You know I did some math before building this thing,” laughs Jody Mollet, the brain behind this twin-Cummins creation. Ever since it surfaced on the Internet after Scheid’s 2016 Extravaganza, he has been overrun with both questions and criticisms. He goes on: “I didn’t know for sure if it will work or not, but isn’t that kind of the point…to try something nobody’s done before?” Mollet concedes that the elephant in the room is the weight question; a lot of folks won’t install one Cummins because of weight, and he has two. “The front axle is rated at 3,200 pounds, so we’re pretty much maxing it out,” he notes. “But in theory it should work.”

Before he started work on this twin- Cummins project through his shop, Plowboys Diesel, Mollet sorted through a few different candidates for the swap. A first-generation Dodge wasn’t wide enough for two engines, so in the end Mollet went with a classic, a ’70 D200. “Although it looks sort of stock, that’s just a trick,” he says. The frame was built out of 2×4-inch and 2×6-inch 0.187-inch-wall tubing, with a radius-arm front suspension up front and a triangulated four-link out back. “We know the suspension needed a lot of weight-handling capability, so airbags made their way to all four corners to handle the heft,” Mollet says.

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From the outside, the ’70 D200 is going to look mostly stock, except for the big wheels and tires. Mollet says that he knows the rat rod look is in right now, but he does want to paint it before it’s finished—possibly charcoal gray. Above: There’s nothing quite like opening a hood and seeing two engines. Both engines are identical builds and are expected to produce around 650 to 700 hp each, for a grand total of 1,300 to 1,400 hp!

To keep the truck low and mean, Mollet fabricated his own triangulated four-link setup using 1-1/4-inch heim joints. The rear end is a narrowed Dana 70 that will be fitted with 3.55 gears.

The engines were mounted using front mounts and a mid plate, which employs leaf spring bushings to give some sort of isolation between the engines and the frame.

There’s plenty of room up front even with the twin engines, which is good since Mollet plans on running a massive intercooler. The radiators will actually be mounted in the bed, along with some electric fans.

The front frame on this D200 is all custom to support the weight of the twin engines. Instead of a normal leaf spring suspension, Mollet runs Slam Specialties airbags at all four corners of the truck, which are rated at 2,500 pounds each! The airbags are a good choice when you have more than a ton of engine weight hanging over the front end.

Other than the weight, the other main concern was joining the two engines together and sending the power to the rear wheels. From twin transmissions to multiple rear ends, there were myriad possibilities; ultimately, Mollet decided on a single stout transmission and a single rear end. That still left the trouble of joining the Cummins engines together, which was when he sought out Modern Machine in Van Buren, Indiana. Modern built a combining box for the Cummins engines, much like those found on multi-engine pulling tractors. The combining box uses a drive that ends in a single Cummins-style crank-shaft end that will bolt to a triple-disc converter and manual valve body Dodge 47RH transmission.

The twin engines are 5.9L Cummins 12-valves, which can be found in ’94-98 Dodges. Mollet’s aren’t stock however, as both engines have ARP head studs, a fire-ringed head from Quality Machine, and a pump, turbos, and injectors from Area Diesel. Mollet estimates that the twin powerplants will be in the 650- 750hp range (each), giving a total power output of 1,300 to 1,500 horsepower along with about 2,000 lb-ft of torque. “I know there are more powerful trucks out there,” he says, “but that amount of horsepower ought to move the truck down the road pretty well.”

Mollet mounted as many external systems as possible to the rear of the truck in order to offset the weight up front. That means a Viair compressor with twin tanks, the fuel cell, and the batteries are all mounted behind the rear wheels.

Here’s an answer to the question everyone asks: How are the engines linked? A combining box from Modern Machine does the job, and will send power through a single transmission that’ll be mounted in the factory location.

Built by Area Diesel, the two 12mm injection pumps feature a few tips and tricks to get its flow up to 360cc of fuel. A wild fuel system isn’t needed to make a lot of power when you have two engines.

The cooling system is quite interesting. Mollet plans on “Y-ing” the two engines, then running coolant through the framerails and back to radiators that will be mounted under the bed. This should give the system huge volume to help keep the twin engines cool.

The turbochargers are also provided by Area Diesel. Each engine will run a 57mm/66mm compound turbo setup, which means the truck will have four turbos in addition to its two engines! Boost is estimated to be in the 60 to 70psi range when the engines are complete.

Mollet is honest about his project being far from complete. “I do have goals, and one of them is for it to be running and driving by the end of the year,” he says. “It’s not like your local parts catalog has a ‘twin-engine truck’ section, so sometimes it goes slower than I’d like.” Whenever it’s finally completed, he will definitely have a show-stopping ride unlike any other. In a world where more and more trucks are built from off-the-shelf parts, it’s truly interesting to see an enthusiast take a completely different path. Our hats are off to Mollet’s dare-to-bedifferent attitude, and we look forward to seeing his progress in the future. DW

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The Lobster Wagon: 1st Gen Crew Cab

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Pinaki Bhattacharya

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