Originally Posted by hotrod
The highest load the connecting rod big end sees is not on the power stroke it is at TDC as the intake stroke starts. Especially on throttle lift engine braking, where intake manifold vacuum is trying to pull up on the piston as the crank is trying to pull it down.
At TDC the load is upward (toward the piston) as the recipocating assembly changes direction and this pull tends to try to stretch the big end of the rod into an oval shape.
really? Ive never thought of that....huh. i always assumed the highest load was on the power stroke trying to 'compress' the rod.