I see moly, cast, gapless, and Im not real sure what to go with. Whats the pros/cons to each type of ring?

For starters check out this article:

http://www.carcraft.com/techarticles/77899/index.html

A lot will depend on what you plan to do with your motor: blower, nitrous, naturally aspirated? You'll probably want moly rings. I haven't heard very good things about the gapless rings but if you want to pay extra go for it. For what it's worth I've had great luck with Speed Pro Plasma moly rings.

AND, please remember they don't make "chrome-moly" rings!!

A sure sign of a green gearhead, imho..

They make chrome rings and they make cast-iron rings filled with moly or what's called moly rings BUT not both together..

Just trying to educate a little here is all..

pdq67

The plasma moly cast iron rings seem to be the way to go, except I still don't know about these gapless rings. They seem to be a good idea from reading, anyone have personal exsperience with them?

I have been running gapless rings for the past 14 yrs. Both from C & A and Total Seal. As far as Static Leakdown readings go, they are Great .. If its a Forced Induction Engine or runs Alky they seem to be the choice. But I'm not so sure they are all they were claimed to be as far as Carb'ed N/A Gas Engines go. I've been hearing lately that they actually cost HP. The Engine I am building now I went back to File Fits.

You will not fine anyone that will produce dyno numbers that show repeatable HP gains from a sealed 2nd ring design. Not the C&A Z or the total seal two piece. The second you start the engine the 2nd ring don't mean squat. I also got suckered graemlins/clonk.gif into that for my race engines but got wised up by some NHRA Comp racers... graemlins/hurray.gif . For the very best ring seal, get the best hone (with plates) you can and then do a very carefully file fit Plasma Molly ring install job. One cylinder at a time. If you go to big, toss the ring and get a new one... It takes me about 4 to 6 tries per ring, till it's good. It's time consuming but worth it. Also piston to cylinder clearance is critical. The piston will rock, for sure and the more the clearance the more havoc it will of on sealing of that top ring. CBB with forged slugs, try and start with no more than 5 and no less than 3. It's hard to find a shop that can hold that kind of tolerance. Watch them hone and make sure the check the bore often top and bottom and sideways with the dial bore Gauge. Tell them it's critical and bribe with a bottle of Jack or Case of brew ski before they start. graemlins/beers.gif


On a real race engine there is just a TON of HP to be made with a top quality ring seal...... graemlins/thumbsup.gif

never went fast with gapless, always ran good with file fit, i'll go along with using them on forced induction as well but they must create some drag or more tension than a conventional ring that you don't reap the benefits on a N/A type engine. i understand racers running on N/A methanol prefer the gapless to help reduce the condensation and contamination issues also.