I have already asked the question of piston diameter size and efficiency in an earlier thread but i'll recap.(adsbygoogle = window.adsbygoogle || []).push({});

My question was that is it true that the larger diameter piston have a larger propensity to overcome the mechanical loss of fricition due to the piston rings contact with the mating surface inside the piston walls.

The resounding response was yes, but I wanted to clarify 2 factors:

1. Would it matter if the the rings were lubricated by water instead of oil?

2. Would it be correct to express it in a mathematical type proof by using this method:

Circumference formula : pi * 2*radius

Area formula : pi * radius *radius

if we cancel out the constant pi from each equation , we have

circumference forumla : 2 * radius

Area forumla : radius * radius

Thus, for any radius, we can see that the larger the radius, the area formula will have a factor of radius squared, while the circumference formula will only be radius times 2.

Is this a mathematical type of expression we can make to show why larger pistons will be more likely to overcome piston ring friction? The fact that larger radius will have result in a larger area factor relative to the circumference of the piston?

thanks

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# Piston diameter size, fricition, mathematical proof

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