Quote:
Originally Posted by serialk11r
Hey you guys so I was wondering, a lot of pages back Exage I think was talking about engine geometry, and rod length and whatever. I was wondering, how essential is it to have longer rods with higher rpm? Longer rods create less friction and loads, but friction is not even linearly related to stroke/rod ratio (the inverse of the rod/stroke ratio), so clearly that's not the big issue...the piston acceleration is decreased but again it's not a very big difference either... could the main issue be that the piston spends less time near TDC?
I made "measurements" based on pictures that we have and it looks like the rods are as I predicted, somewhere around 1.5 times the stroke, which seems a bit short as every high rev engine made before has 1.6 or higher.
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Something to do with the acceleration forces. With rpm and stroke we can calculate mean piston speed, but when we add in the rod:stroke ratio we (well people better at math/physics than myself) can calculate the peak acceleration forces of the piston and rod. Gives a more accurate view of the stress on the rod.