Editor’s Note: EngineLabs has launched a new feature titled Homegrown Horsepower, and we’re looking for all types of engine projects based in your garage. This unique radial engine — built with air-cooled cylinders from a VW engine — certainly qualifies, and the story told in the video is very compelling. If you want to see your engine featured in this new series, email a few quality digital photos, background information on your project and list of the engine’s components to [email protected] We can also include YouTube videos of the engine on the dyno or test stand. So, don’t be afraid to show off your engine. Send us the details!!
The radial engine is a design unlike any typical automotive engine, in that it uses a centrally-located crankshaft that drives the connecting rods through the use of a master connecting rod that is directly connected to the crankshaft and typically used in the upward-facing cylinder.
As the axes of all cylinders are coplanar (they are located inline with the crankshaft) the other connecting rods are driven from rings that are placed around the master connecting rod assembly. In the majority of applications, the camshaft is driven off the crankshaft and actuates long pushrods that act in a manner typical to an automotive engine, only optimized for use in the radial. Each cylinder has its own cylinder head.
Hand-building a 7-cylinder radial engine is no small feat as evidenced by the immense detail shown throughout this video. Cylinder heads and cylinders are machined and modified from air-cooled VW engine parts, but the crankcase, crankshaft, and majority of the hard parts appear to completely custom-made for this application.
The builder shows a serious appreciation for the process of telling his story through the video production – although he doesn’t cover every step, he does display just how difficult and impressive this build is. It’s a testament to what can be done in a home machine shop if one has the skills and the tools to turn a project like this into reality.
The engine displaces just over 2.0L, and although there is a propeller attached during the engine-start portion of the video, there is no indication whether the engine is destined for use in an airframe or is just a conversation piece.