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That entire variable cylinder configuration routine seems to me to be a lot of (old) advertising hype. The concept seems to be that the public thinks fewer cylinders burn less fuel, so you can have your eight cylinder cake and eat four cylinder fuel. Purest balderdash.
The engine is still pulling eight cylinders worth of rings back and forth in the bores even if it's not compressing any air. The cam is still trying to lift sixteen (plus) valves and compress sixteen (plus) springs, ETC. You can't reduce a lot of the pumping losses if the whole mechanism is still rotating/reciprocating/wearing.
Power is proportional to the amount of air/fuel mixture going through the pump (assuming the same combustion efficiency). The reduced air/fuel mixture (of the variable cylinder configuration at cruise) presumably produces increased economy. BUT, it requires exactly the same amount of power to push the vehicle down the road at cruise using 4,6,8,10 or 24+ cylinders. The conventional method of accomplishing this enterprise is CLOSING THE THROTTLE so less air/fuel mixture is pumped through. Has the exact same effect with much less complicated design.
So if you want more efficiency, just run at lower power settings. You will accomplish the desired result.
Retracting soapbox,
Jack Ford
----- Original Message ----- From: "Ernest Christley" <echristley@nc.rr.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Monday, May 09, 2005 3:16 PM
Subject: [FlyRotary] Re: center rotor OFF
Russell Duffy wrote:
OK, make me look it up :-) Apparently, they stop the valves from opening, rather than leaving them open. I couldn't find anything that gave details of exactly what point in the sequence they stop the valves, so the cylinder could either be full of air (silly and wasteful of power), empty of air (would cause vacuum that would be as bad as the compression force), or perhaps somewhere in between.
Other than friction losses, you'll get back everything you put into compressing the gas in the cylinder, Rusty. The process will be totally elastic.
-- This is by far the hardest lesson about freedom. It goes against
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