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Tom JohnsonMonrovia, CA             11/05/2007

Atkinson Cycle Engine

I built this engine and ran it in 2006.

It has an 1   bore. It completes all four of its strokes in a single turn of the crankshaft.

This is the first internal combustion engine that I built. I made this engine from plans in a book by Vincent Gingery.

This engine does not have a separate camshaft or gears. It fires every revolution of the crankshaft.

Because of the geometry of the crank mechanism:

The intake stroke is .825

The compression stroke is .710

The power stroke is 1.042

The exhaust stroke is 1.157

I made it from bar stock instead of the castings called out in the book, changing the original configuration of the valves and the rocker arms. My engine is air-cooled instead of water-cooled. I found it not necessary to use a head gasket since the head to the cylinder liner sealed the combustion chamber perfectly. Doing it this way improved the heat transfer from the head to the cylinder making the engine run much cooler.



Copyright 2007,  Florida Association of Model Engineers and engine builder as noted above, All rights reserved.