CMP alloy pistons

[Mike K]

Originally Posted by Hanno Spoelstra

What’s the advantage of alloy pistons? Lighter weight so higher revs, eh?

Were these an aftermarket item, or were they factory fitted in some cases?

These are Aftermarket Hanno . Yes, less mass moving up/down = less force on the rod bearings and longer life , and higher revs are possible but I would not like to test that theory myself. I think they are about 25% lighter than the iron pistons. The CMPs had the heavier iron alloy pistons fitted at the factory.

The iron pistons , I've heard the top section can fatigue and break off One advantage of the iron pistons is, the top ring groove doesn't wear like the alloy pistons suffer from.