1/4 Scale Cirrus

         I built this engine at the request of Robert Washburn who asked me if I would be willing to do a construction article for SIC magazine. He would provide the drawings and castings and I would write the machining instructions, take in progress photographs, and explain my construction methods as I went along. In return I would get to keep the finished engine. It was a lot of work but it helped me cement the procedures and writing style that I would later use to write my Offy construction manual. I had built Bob's "Skycharger" engine as he outlined in the Homeshop Machinist earlier. He got me started in a new direction.  

Ignition: Spark
Bore: 1 1/16 in.
Stroke: 1 1/4 in.
Displacement: 73.77 cc
Max RPM: 6,000
Construction Series by Ron Colonna:
 Strictly I.C. Magazine
Dec. '92 to Nov. '93

Click Photos for Enlargements