On 27 May 2005 08:47:23 -0700, "Sport Pilot"
wrote:

Bob, Last time I took apart a VW, and Corvair, they shared the same con
rod. Not sure about aircraft engines, but pretty sure the one in the C
150 and the C 172's are not boxers. So I think you have the definition
right, just misinformed about the commanality of boxer engines. They
are uncommon enough that the manufacture makes a deal about the engine
if it is a boxer, such as Ferarri, and BMW(?).

I've never given this much thought before. Which design is called a
boxer engine? Let's keep it simple and talk about a twin cylinder
engine. Is the design in which the connecting rods share the same
journal the boxer, or is it the design in which the two connecting
rods have their own throw and own journals. This second type seems
like it would require greater cylinder offset in order to accomodate
the crankshaft throws, and would probably vibrate more.

So which is considered the boxer design? Is the other design simply
called "horizontally opposed"?

Thanks, Corky Scott