In <3.0.1.32.19970829082453.00c89d8c@value.net>, Skip Kelsey wrote:
>A.B.
>
>I would hesitate to motor continuesly at 4500 RPM. The engine should be
>kept at about 4000 RPM. THe wear rate on the engine increases dramatically
>above 4130 RPM.
In a TD, with the 5.125 rear end, 4500 rpm is 878 rev/min of the rear
axle. The wheel radius is between 11 and 12 inches, depending on the
tire you have. Let's say it's 12 inches (1 foot), then one gets 6.28
feet per rev. That's 5514 feet/min or 62.7 mph. 4130 rpm is 57.5
mph. If you have a lower profile tire (radial) this drops to 5054
feet/min at 4500 rpm or 57 mph. 4130 rpm yields 52.3 mph.
4130 is all well and good, but sometimes ya need to go 55. A
feller's gotta do what a feller's gotta do.
A. B. Bonds
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