View Single Post
Old 12-26-2009, 09:18 PM   #15 (permalink)
Moderate your Moderation.
Join Date: Nov 2008
Location: Troy, Pa.
Posts: 8,919

Pasta - '96 Volkswagen Passat TDi
90 day: 45.22 mpg (US)
Thanks: 1,369
Thanked 430 Times in 353 Posts
Originally Posted by NeilBlanchard View Post
Yes, it is a cam driven engine, like the Revetec (that I mentioned earlier). The problem with a crankshaft engine is the maximum pressure occurs when the connecting rod in nearly straight up, and there is very little leverage that can turn the crankshaft. (A lot of force is trying to bend the crankshaft...)

With a cam driven engine, you can design the amount of leverage you have; rather than being locked in to a sinusoidal piston motion.

On the Shepard engine, is the combustion sleeve inside (and concentric with) the rotating cam sleeve? I wonder why the levers are required at all, then?
Check out Honda's R-series engines. The crank is slightly offset, so TDC is actually slightly aft of traditional crank angle, and the combustion pressure builds when the piston/rod assembly would be creating a leveraged force on the crank shaft.
"ʞɐǝɹɟ ɐ ǝɹ,noʎ uǝɥʍ 'ʇı ʇ,usı 'ʎlǝuol s,ʇı"

  Reply With Quote