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Old 05-14-2011, 10:25 PM   #45 (permalink)
gone-ot
...beats walking...
 
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...see Fig. 10-7, on page 247, of "The INTERNAL-COMBUSTION ENGINE, 2ed., 1961, International Textbook Company, by Professors C.F.Taylor and E.S.Taylor of MIT:

Fig. 10-7. Volumetric efficiency vs. mean piston speed and Z of the MIT geometrically similar engines under similar operating conditions.

...it's a graph showing that Vol. Eff. "peaks" at piston speeds between 1000 and 1500 fpm, which corresponds to Mach index air-flow Z numbers of 0.3-0.4-0.5.

...Z number is tied into both piston speed and valve size (ie: trying to suck/push air past/though changing valve areas), which gets into Mach index (Z) and maximum air speeds...but, piston speed 'starts' every thing.




addendum: see posting #53 below

Last edited by gone-ot; 05-17-2011 at 04:52 PM..
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