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Old 12-06-2010, 06:55 AM   #145 (permalink)
NeilBlanchard
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The peak pressure is bending the crankshaft sideways, rather than spinning it. It spends a relatively long time doing this. The connecting rod position relative to the crank center is one of the main reasons that current gasoline engines are so horribly innefficient -- 20-30 sucks, frankly.

And the pressure disputes as the volume expands. So by the time it has the maximum mechanical torque at 90 degrees past TDC, the pressure has dissipated a lot. In a steam engine, the pressure stays virtually constant all the way through the stroke.

The Revetec engine nearly doubles the efficiency of the bog standard design. So does the Atkinson cycle Prius engine.

The valve train is another major drain on efficiency -- it takes a lot to push open the typical poppet valves that require springs. Though, I don't know if there is an efficiency gain with a desmodromic valve train like Ducati's?

I am trying to get people to think unconventionally -- what we are doing can only be tweaked; when we need a quantum leap. Rotary engines (not necessarily Wankels) have an response to the crankshaft issue -- some of them at the very beginning of this thread look very promising.

My proposed design was an attempt to answer these problems without abandoning the crankshaft.
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