Russell Sutton’s Honda 9 Cylinder Radial Engine Progress Report

What could be better than a 9 cylinder radial engine? Why, a home built 9 cylinder radial, of course! Russell Sutton continues to work on his engine projects, (yes, I said projects, because he’s already beginning his next engine) and we just received the latest updates on the radial build many of you have been following which began many years ago using 9 cylinders and heads from the Honda XR600 single.

In the last video of this project, Russell said he was setting this radial up as a running display and, to that end, it’s been mounted on a permanent stand with a fuel tank, an oil tank and cooler and all of the associated plumbing. The next step will be to engineer a full engine management system and for that, he’s purchased a Megasquirt ECU and added extra processors to control spark and sequential fuel injection.

Russell’s original plan was to install a PSRU (propeller speed reduction unit) and propeller, but with funds already being diverted into his next incredible project, he’s decided instead to go direct drive with a wooden Sensenich airboat prop from a Lycoming 0-540 engine. The engine will run and sound better with a proper load and this prop should do the job. When you think about it, some might even say a radial doesn’t really look finished until it has a big prop on it and I might go along with that view.

Ian Drysdale is machining the shaft and flange and the front housing is on the engine waiting to be fitted up. The housing is an LPG gas cylinder Russell cut in half and welded to the face plate.The LS1 Chevy coils are mounted around the engine along with the injectors. The throttle body also comes from a 5.7 LS1 Chevy.

The electrical box is mounted beside the oil cooler with a gauge panel and awaits the ECU and all of the necessary wiring. The fuel tank is a stainless steel 45 liter fire suppression cylinder while the oil tank is two hand held 9kg fire extinguishers welded together to give a 20 liter capacity.

This 540 cubic inch Lycoming’s output is 300hp at 2700 RPM so Russell’s 488 cubes are going to get a good work out. Russell figures the wooden prop will probably kill the engine off at about 2500 RPM though he won’t know for sure until those blades start to muscle their way through the air. Though not as aggressive as the PSRU and big carbon prop, the 70 inch Sensenich has the advantage of giving this radial a very proper vintage look.

It shouldn’t be too long before we see how it all comes together in its final form. What an amazing project! We’re almost there.