They used flatheads for compressors a lot back in the 30's.... 4 cylinders did the work, 4 did the compression. Different manifolds and stuff, but not all that uncommon.
When I was farming years ago, the tractor tire repair guy had one of those for his compressor. He ran no exhaust but stubs. Drove us nuts every time that dam thing would kick in....
The Jalopy Journal
