[SEL] Question about side shaft cam stoppers.

[Curt]

Some of you may know our local prolific model builder Doug Kelley and 
have seen some of his exquisite work. His latest model of the Miller 
engine at Coolsprings (using minerature ignitors!) has been working 
great for several months, and apparently he is ready to design his next 
model.
He called last night asking I dig up information on Callahan engines or 
other cam stoppers. Perhaps I am recalling incorrectly, but I seem to 
remember that on a Callahan the shaft continues to rotate, but the 
governor latches in and out the cam lobes that are on a sleeve on the 
side shaft.
But Doug specifically asked about an engine in which the entire side 
shaft is latched in/out by a governor acting at the back of the shaft 
near the crankshaft. He wants to build a model that uses a mechanism 
like this, where the entire shaft rotates and then the entire shaft is 
latched out.
So the question is, what engine would this be, and is a detailed 
explanation available, and are pictures available that Doug can pattern 
his design from?
Thanks,
Curt Holland
Gastonia, NC