Cast vs Moly Rings

Moly doesn't seal any better than cast iron. Doesn't last any longer either. In fact, beat on them a bit and the moly comes out.

So, we are again dealing with decades old nonsense about ring seal and why something was done the way it was.

I don't know of a serious engine build that uses moly any more. There have been entire firsts cut down to manufacture the paper and rivers of ink expended to explain the story of moly rings. Most of it is Madison Avenue bullcrap.

If you can't afford a set of gapless top rings from Total Seal, just do the cast iron rings. Finish the bores to 280 grit, hit them with a plateau hone for 8-10 strokes and forget it.


Sometimes you have to get off Broadway to see the show.