What's the difference?

 

it's what the face of the ring is coated with, moly, chrome, or bare iron. there are quite a few variations on the coating, but basically it's moly, chrome or ductile iron. the moly or chrome is applied over a ductile iron ring. i use moly or plasma moly for everything i do. chrome is hard wearing and from what i hear is popular with dirt track racers.

 

It also takes a different honing for each one. Mostly the grit/grade thats used on the cylinder.
Plasma's seal quicker, and are more tolerant to an 'ok' hone job.

Ron

 

So, if I run with regular Hasting moly rings in a street 350 with light racing duty, I should be fine? My brother's saying they're "OK" rings for what I'm doing, but I don't wanna spend an assload of money on a set of rings that I really don't need.

 

Yes, those would be OK. Make sure the block is honed with about a 400 grit stone for those.

Moly seats faster than chrome, but won't tolerate dirt. Chrome is what they use for diesel truck motors that run half a million miles between rebuilds.

 

Well, I'm about to get the block freshly bored .030 over, so I'm sure a clean hone won't be an issue.

 

The "clean" thing has nothing to do with the hone... more to do with air filters...

 

When I said clean, I meant it in the sense that the cylinders should be nice and smooth cuz they're freshly cut.

 

True. But, the shop can use any of a range of grit stones. Chrome rings like a somewhat rough hone stone, like about 240. If you put moly rings in a cylinder like that, they'll wear very quickly; they might even wear completely through the moly facing before the walls are broken in. On the other hand, if you put chrome rings in a cylinder honed with the 400 that moly likes, they'll take forever to seat, and the motor will burn oil mercilessly for its first many thousand miles.

Bottom line is, make sure you tell your machinist what rings you plan on using, so he can prepare your block accordingly. It's like a paint job: the success of the finished product is heavily influenced by the prep.

 

Cool, I didn't know that. So, it looks like I'll be going for Hastings moly rings. I just haven't found the shop that's doing my bore, yet, since the place that I brought the block to for the cam bearings (before i knew I needed a bore) screwed them all up.

Next mission. Pistons that give me at least 10:1 but not more than 10.5:1 with a 58cc head. I wanna be able to run pump gas, but I don't wanna kill it when I send up switching to a 64/67cc head (screw 76!)