Thread: 3 vs 4 cylinder
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Old 09-15-2008, 09:50 PM   #16 (permalink)
guitarterry
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Quote:
Originally Posted by dcb View Post
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Lets say that you have a 2 cylinder engine with pistons of radius 1, the total circumference around both pistons is 12.57.

Whereas if you have a single piston engine with the same stroke/displacement it would have a piston radius of 1.414 and a total circumference of 8.88.

This means that the single piston engine has about 1/3 less contact with the cylinder wall, and thus significantly less friction, even though the stroke and displacement are identical.
This is wrong, wrong, wrong. again apples to oranges. if u turn the one cylinder with a area twice in a minute. that would give u a total of 17.76. while the two cylinder turned once is still 12.57. here is what we are doing. a three banger turned 1.3 times in a minute would = the area, friction, and everything else, BUT the alt, water pump, etc would turn slower. plus frictional losses increase with the square of speed. Both would fire 4 times a minute. AGAIN WE ARE TURNING THE ENGINES AT A DIFFERENT SPEEDS TO MAKE FRICTION EQUAL.

Last edited by guitarterry; 09-16-2008 at 09:38 PM..
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