[SEL] The McVickerish Engine and video

[Larry Evans]

Jim,

The Aermotor's cam shaft has a gear four times as large as the crankshaft 
gear so the crank turns four times instead of the usual two times per cam 
shaft rotation of a typical four stroke engine.  The cam is shaped to hold 
the exhaust valve open all the time except during the firing cycle if the 
governor calls for it.  This was probably the company's way of doing away 
with a belt driven fan for cooling.  Another variation was the Gade air 
cooled engines that had an exhaust port at the bottom of the stroke to dump 
the hot gasses out and then the exhaust valve allowed the final clearing of 
the cylinder.  This also did away with the need for a cooling fan.

Larry

At 04:54 PM 3/23/2010, you wrote:
>How did the Aeromotor hold the exhaust valve open for 5 strokes? Venting 
>the cylinder that way does make sense from a cooling stand point.
>  Jim K.

Larry Evans
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