Compressor Engine

Missouri Collector Breathes New Life into Au - To Air Compressor


| February/March 2004


I wonder how many collectors have ever seen -much less owned - an Au-To flywheel air compressor? Better yet, how many collectors have seen an Au-To air compressor converted to an engine?

After seeing a few engines made from air compressors some 15 years ago, I decided to make my own. I attended numerous auctions looking for a compressor that would make a good engine, and for $5 I picked up an Au-To compressor. The old compressor sat around my shop for a while, and then I moved it to my storage building, where I forgot about it until 2002.

Getting Started

Picking the project back up, and not sure exactly how to proceed, I worked on my engine by trial and error. Using some drawings of other engines as a guide, I finally adapted a concept I thought would work.

I wanted the finished engine to have dual flywheels, but the compressor was only fitted with a 14-inch flywheel on one side and a ring gear of equal size on the other, which, I assume, was geared to an engine that supplied power to the compressor. For the second flywheel, I used one from a Cushman Binder engine. It's a little larger, but at some point I'll turn it down on a lathe to the same size as the original. The Cushman flywheel had a tapered center hole, so I reamed it straight and installed a steel bushing to size it to the Au-To's 1-1/8-inch crankshaft.



I sourced a 2-to-1 distributor gear set from a Volkswagen, which I decided would work well to drive the vertical flyball governor and camshaft I planned on fabricating. Not surprisingly, the Volkswagen distributor gear set also had to be sized to fit. Fixing the larger drive gear was no problem, as all I had to do was machine a bushing to reduce its inside diameter to 1-1/8-inch. I knew I'd have to machine the smaller driven gear, but it was so hard I had to anneal it before it could be machined. I did this by heating it cherry red and slowly cooling it in a bucket of sand. Then I turned it on a lathe to match bushings that I had available.

The compressor's original crankcase was completely enclosed, but I thought the finished engine would look nicer if I removed some of the non-essential cast iron housing at the base so people could see the crankshaft.














SUBSCRIBE TO GAS ENGINE MAGAZINE TODAY!

Gas Engine Magazine A_M 16Gas Engine Magazine is your best source for tractor and stationary gas engine information.  Subscribe and connect with more than 23,000 other gas engine collectors and build your knowledge, share your passion and search for parts, in the publication written by and for gas engine enthusiasts! Gas Engine Magazine brings you: restoration stories, company histories, and technical advice. Plus our Flywheel Forum column helps answer your engine inquiries!

Be sure to take advantage of the Square Deal Subscription Program.

  • No Missed Issues.

  • No Renewal Notices.

  • No Additional Cost.

The Square Deal Subscription Program is designed as a paperless transaction with automatic renewals at a preferred low rate.   With advanced electronic notification, a 100% satisfaction guarantee and an easy opt-out plan, the Square Deal Subscription Program is the best value, risk free, eco-friendliest way to subscribe.




Facebook YouTube


Copyright 2018, All Rights Reserved
Ogden Publications, Inc., 1503 SW 42nd St., Topeka, Kansas 66609-1265