Sort of--it's really the ratio of stroke to rod lenght that matters. Maximum
piston accleration is G=N** x L/2189(1+1/2A)
Where G is max piston acceleration in feet per second squared, N is RPM, L
is stroke in inches and A is the ratio of the connecting rod length between
centers to stroke. Short stroke engines can have short rods and low piston
acceleration. It's long stroke engines that need very long rods.
-----Original Message-----
From: owner-fot@autox.team.net
To: fot
Sent: 5/20/2004 9:13 AM
Subject: crankshafts
A big reason that the forces at TDC are so great is not due to
speed. Piston speed by itself doesn't matter much except as
a determining factor in friction. The big deal is acceleration and
that is at its worst at TDC. One of the reasons long rods are
a good deal is the more favorable piston dwell at TDC achieved
with a gentler "jerk" at direction change.
art d
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