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Old 01-30-2004, 08:31 PM   #69
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Re: Pushrod vs. SOHC vs. DOHC

Originally Posted by Evil Result
when i think of a "muscle car" i think big V-8's with big torque at lower rev's.

higher reving engines create more friction over time than lower reving engines, but that depends on design. Higher reving engines can also be geared down to produce the same ammount of torque at the wheels as a "muscle car" V-8.

A question i have although off topic is.... fuel effiency, what would have better fuel effiency based on equal horsepower outputs say 500hp, using the same mechanical design. This means same fuel delivery, ignition, cam system, induction, exhaust, ect, ect. Just a difference between revs and displacement, which would be more efficent, higher displacement lower reving engine, or a lower displacement higher reving engine?
Friction loss can in general be estimated from mean piston velocity, longer stroke and higher rpm = higher friction loss.

Part throttle efficiency tend to be higher for small displacement engines due to smaller pumping losses.
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