Bob Currie, oakland, CA, 1968, Barracuda, Formula S, 340
The MP “A” engines book said one can turn the pistons180 degrees in the block. It is supposed to be a trade-off of more torquefor more noise.What is your take on this? Specifically: Does this affect thelongevity of the rotating assembly and pistons in particular?
Ideally, the piston pins would be centered in the pistons – which is the wayvirtually all aftermarket pistons are manufactured. But, for noise reduction(piston slap) due to the variable machining tolerances in the ’60s and 70s,Chrysler offset the pin a tad to keep the skirt “loaded” against thecylinder wall. Swapping the pistons on the pin reveres this, reducingfriction a small amount. No harm done, just a little noisier when cold.But – one very large caveat! This works safely only with low compressionpistons – ones with either NO valve clearance notches, or four (forside-to-side interchangeability.) Pistons having only TWO clearance notchesCANNOT be swapped.