Anyone got a set of used 7cc high compression 425 pistons in good shape that they want to part with?
... Or maybe a set of stock oversize pistons?

I just pulled apart a 425 that I thought hadn't been opened (my own failure of observation), and found that the rings had been replaced with rings that were too thin - ALL were broken (engine had good compression, by the way), and they had hammered the grooves to about 0.010" larger than they should be. I could probably get it to work with a new set of rings, but not really well, and it wouldn't last.

Thanks,

- Eric

 

Eric I would suggest a set of new pistons. I have pulled apart many 425's and most had damage to ring lands and worn skirts. The stock ones were cast. There is also pitting that takes place. You may find a set of slightly used ones that would work but as far as stock ones I would not hold my breath. You may want to try an ad on ROP. Guys there are always building engines and swapping parts. Good Luck

 

Yeah, Joe, I know what you mean.

This was supposed to be a quick clean-up and reassemble type motor, and I'd be happy with stock-level parts, but it's looking more and more like if I want it to run I'll have to spring for more than I had intended.

The annoying thing is that the same person who put in the wrong rings rebuilt the heads with new valves and guides, new springs, and I think new seats (I'll go look in a minute), and they look great, but then they had to go and put in new top rings (only) that were to narrow.

By the looks of the engine, he probably drove it for a few thousand miles before it started smoking, then parked it for at least ten years, then sold it to the guy I bought the engine from.

Do you know of any sources for non-racing, non-hotrod 425 pistons? I know they're hard to find.

- Eric

 

I would recommend EGGE for pistons. It is better to call them as their catalog is not easy to decipher on line. Stock style OEM is what they sell and i believe they do their own manufacturing. They had my 400 pistons in stock!!

 

Yeah, I'd thought of them. We bought a set of pistons for a Lincoln V12 years ago, and they DO seem to have everything.

It's getting harder and harder to do this cheaply...

- Eric