04-04-2019, 05:32 PM
Hi Austin
In the middle of a four crank the adjacent piston is firing, so at revs and full throttle the net "'upward" load on the crank is partly countered.
The downward load at bottom of stroke is not so great because the pistons change direction less abruptly.
(A concept which is not easy to grasp. Imagine a 3 inch stroke with a conrod 1 5/8 long. The piston barely moves for the lower half rev and executes nearly entire stroke during top half rev)
In the middle of a four crank the adjacent piston is firing, so at revs and full throttle the net "'upward" load on the crank is partly countered.
The downward load at bottom of stroke is not so great because the pistons change direction less abruptly.
(A concept which is not easy to grasp. Imagine a 3 inch stroke with a conrod 1 5/8 long. The piston barely moves for the lower half rev and executes nearly entire stroke during top half rev)