Most people would have walked right past the rotting 1958 Lyn Airvan sitting in a junkyard, its interior filled with Harley-Davidson motorcycle parts and its exterior hidden beneath brush and mold. Charles Lorenzo of Bensalem, Pennsylvania, saw something entirely different. He envisioned a one-of-a-kind rig powered by one of the most respected diesel engines ever built.
Over the next several years, that vision became reality. Today, the once-forgotten van rides on four-wheel drive and is propelled by a Mercedes-Benz OM617 turbodiesel, creating a machine unlike anything else.
A Rare Airvan Worth Waiting For
Acquiring the Airvan didn’t happen overnight. Charles spent two and a half years convincing the owner to part with it before finally purchasing the van for $4,000.
Virtually no history accompanied the vehicle. There were no exterior markings to identify its former life, leaving the VIN on the steering column as the only clue to its origins.
The lengthy wait wasn’t time wasted. During those two and a half years, Charles refined his plans and mapped out every major modification before the project officially began. Over the following two years, those ideas evolved into the remarkable build seen today.
Legendary OM617 Diesel Is The Heart Of The Build
The Airvan, which sits on a Chevy C chassis, had a seized 235 cubic-inch inline-six gasoline engine. Charles had no intention of bringing the original powerplant back to life. Instead, he located a 1984 Mercedes-Benz 300D donor car and removed its legendary OM617 turbodiesel. Along with the inline-five diesel came the Mercedes-Benz radiator, electric cooling fan, and four-speed automatic transmission.
With more than 50 years of off-road experience, he knew the diesel deserved four-wheel drive. To make that happen, he installed a divorced Ford Highboy NP205 transfer case operated by a twin-stick shifter purchased from Amazon and modified to fit the Airvan.
Jeep Axles Complete The Four-Wheel-Drive Conversion
Charles salvaged both axles from a donor 1999 Jeep Grand Cherokee. He improved the front Dana 30 with manual locking hub components sourced from an earlier axle. Both differentials continue to run factory 3.73:1 gearing.
Rather than replacing the original suspension, Charles rebuilt the Airvan’s factory leaf springs and retained them for the completed project. The van rides on 225/75R16 Firestone Transforce LT tires mounted to Ford F-150 aluminum wheels.
Every System Required Engineering Solutions
Converting a 1958 van into a diesel-powered four-wheel drive demanded far more than simply swapping engines. Charles removed the body from the chassis, built a custom rotisserie, and thoroughly cleaned and refinished the frame before beginning reassembly.
“Next came the fun part, putting it all back together and figuring out where I was going to put all the parts and how to make them work,” he says.
Nearly every component required modification or complete redesign. One of the biggest challenges involved the electrical system. Charles started with an Amazon-sourced wiring harness before extensively reworking it to support the growing list of electrical systems.
“I find the hardest part of the whole process is wiring up the 47 different (and counting) circuits and systems,” he says.
Modern Components Improve Everyday Drivability
Beyond the drivetrain conversion, Charles incorporated numerous upgrades and repairs.
The build includes all-new LED lighting, a Jeep Compass rack-and-pinion steering system, a modified Jeep Grand Cherokee brake master cylinder, and electric windshield wipers replacing the original vacuum-operated units.
Inside, Dolphin gauges with a GPS speedometer provide modern instrumentation. Charles also fabricated a custom engine doghouse and built a one-off heating, defroster, and air conditioning system.
The Diesel Swap Is His Greatest Achievement
We photographed Charles’ Airvan at the 2026 4-Wheel Summer Jamboree Nationals in Bloomsburg, Pennsylvania, and at that time it had been on the road for only about two months.
When asked which modification stands above the rest, Charles answered without hesitation. “Taking an original truck frame and suspension and making it four-wheel drive with my favorite diesel engine and transmission. I find that to be the most challenging yet rewarding part of the whole build.”
That answer says everything about the project. While the Airvan draws crowds because of its rarity, it’s the carefully engineered diesel conversion that defines the build.
Built To Be Used Every Day
Although much of the fabrication work is complete, Charles still has plans for the Airvan. New flat glass has already been installed, and future improvements include paint along with finishing the seating and shelving for his tools.
The best part is that the project won’t become a garage ornament. Charles intends to use the Airvan as his daily driver and work truck while helping members of his church with home improvement projects.
“So far this has been quite a journey, but it’s been worth it because of all the people I’ve met who love it. It makes them happy and it makes me happy. I especially love driving my grandkids around in it.”
Photos by Ken Brubaker and Charles Lorenzo
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