This 1939 Plymouth pickup houses a 12.4 liter Jacobs R 755 radial engine!

Putting a 12.4 liter Jacobs R 755 radial engine in 1939 Plymouth pickup truck, it’s the same as building a spaceship for Mars. This trick is a work of the Corns family, are based in Colorado where they run a salvage yard which is about 40 acres, and has hundreds of vehicles and thousands of parts.


Each Wednesday evening, the Corns family has a tradition of inviting their friends to work on a project car, and the rules for joining are simple ”Love cars, bring beer, and have a sense of humor. Sounds like a place I would love to be. The project for the Plymouth started years ago, when Gary Corns actually bought the car from a regular costumer.

The old Plymouth sat in the yard for more than 30 year until one day, Corns senior found an old seaplane engine a Jacobs R 755 engine. The first thing was to see if the old rad would start, as it was and amazingly it did, with a lot of smoke and noise but it started. The Corns family started looking for a single-barrel updraft carburetor on e-bay, and then they fabricated the parts they needed to fit it to the Jacobs R 755.Once it was fitted, the ignition system could be tuned and the valve clearances were adjusted within specifications, most likely for the first time. The Plymouth truck’s original chassis was beyond saving, so a new tube was welded up and this allowed them to extend the front a bit, to allow proper fitment for the new engine. The body was heavily modified as it was fitted to the new chassis; rivets were used as a hat tip to the aeronautical past of the 7 cylinder radial engine. We has to say that the attention to detail are remarkable. Furthermore watch the video below and enjoy.

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radial engine truck