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Old 12-05-2010, 10:58 PM   #136 (permalink)
NeilBlanchard
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The supercharger would pressurize the tank. Obviously this is a loss, but unlike a compression stroke, in the design I proposed a large offset of the cylinder to the crankshaft center, so you would get a much better mechanical leverage and generate torque with the power stroke (instead of bending the crankshaft sideways), but do the offset reduces the power of the up stroke by a similar amount.

So, I cannot avoid the compression loss, but doing it with the supercharger allows it to keep the advantage on the power stroke.

Quote:
Neil I did look over your proposed design in the first few posts. I believe one of the disadvantages of engines that have opposed cylinders like the old air cooled VW was that I have not seen one of that design that was terribly efficient in the first place.
I think disc type valves are an improvement over poppets in theory, but I am not sure if they have the ability to last and be low maintenance.
Okay, the VW and most opposed engines have separate crank pins, whereas this proposed design, the pair of opposed pistons share a crank pin; so one piston pushes the other through it's exhaust stroke.

Why would an opposed piston design be inefficient? Porsche, Ferrari, Subaru, and plenty of others have had successful flat opposed designs?

My biggest concern related to the configuration of the "Blanchard Cycle" engine is odd ball vibration, that would set up a twisting reaction. Even the BMW Boxers have this. This design is not really "flat" in a true sense...

On the wear and tear on disk valves, I was thinking of using both a radial and a thrust plain bearing. Or, another possibility is to have rotating conical valves with ports through them. This would have a large surface area to support the valve against the pressures in the cylinder, but still be a low-drag rotating design.
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Last edited by NeilBlanchard; 12-05-2010 at 11:04 PM..
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