Letters & Miscellanies

Hot air engine, New Way, engines from Down Under, Briggs & Stratton

| June 2007

Hot air engine

Here is a photo of my hot air engine. I first became intrigued with Stirling cycle engines several years ago, reading about them in various magazines. Then I got a box of books at an auction and one was about hot air engines. I read and reread that book but had a hard time understanding how an engine could run just on hot air.

These engines are extremely rare in Canada. I had the opportunity to see one at the O'Keefe ranch near Vernon, British Columbia. Then things made sense and I decided to build one. I tried to find plans and had no success until I borrowed a copy of Steam & Stirling Engines You Can Build. It describes a 2-inch scale model. From this I scaled to the 5-inch size I had started to build, trying to replicate a Rider-Ericsson.

It is all built from ordinary materials. The cylinder is a section of hydraulic cylinder barrel, 5-inch bore. Most of the linkage has ball bearings. The pump is from brass stock and stainless steel. The power piston was machined from solid bronze. The flywheel came from an old bundle cutter and the firebox was a section of a grain chute. The burner is from a water heater. The firebox is brick lined and has grates so it could run on wood or coal, though I've never tried that. It is too easy to use propane. It takes 10 to 15 minutes after you fire up until it is ready to go. You just give the flywheel a flip and away it goes. It runs about 60-80 RPM and pumps about 100 gallons per hour.

This project was a lot of fun to build and even more fun to watch run. There are no gears, no ignition, no carburetor and no governor. I think I now understand how and why it runs, but it is still hard to explain. This engine is mounted on a skid, together with several other pump engines and water pumps to take to shows.

Don Voss, R.R. 1, Spiritwood, SAS, Canada, S0J 2M0

New Way

This is a 1915 New Way 1-1/2 HP engine before and after. It took about two years to get it running. It is air-cooled, has spark plug ignition and runs backward. The serial no. is 850.