Does any one know whats a better engine ABC or ringed? Does one last longer then the other? Does one have more power?

The power isn't a direct function of the piston/sleeve seal design.

What two engines are you comparing? That might get a worthwhile answer.

Today's engines last a couple of seasons no matter what their piston design. And power is more the result of overall design.

The one thing that is true for sure is that the ring can be replaced relatively cheaply. If you ever need to. Beyond that...... nothing worth mentioning.

I am comparing the Tower .75 ABC 2 stroke and the GMS .76 Ringed 2 stroke.

Performance wise I doubt that any of us could tell much difference. In the old days a ringed engine would hold it's compression longer than an ABC, but the new metals used seem to have cured that with ABC's. The real difference is that a ringed engine will take a lot longer to break in because you will have to give time for the ring to set. Also a lean run early in the life of a ringed engine is the kiss of death. I would say that in the size you are considering, an ABC will be more user friendly.

I have heard that the Tower .75 has a little more power than the GMS .76. I really don't know about that, but I will say that my GMS .76 is such a sweetheart of an engine that I would never even consider getting rid of it. Ever!

My truck has rings. My car has rings. My lawn mower has rings. My chain saw has rings. Even my air compressor has rings. But somehow I'm supposed to be happy with ABC?

That said, I am very happy with my Tower 75 and my Jett engines. I just recognize that they are going cheap on the build.

How anyone could call a Jett a cheap build simply floors me.

John

Broken in and run properly I doubt you'd be able to tell a difference.

Jett, cheap??? Someone has deep pockets. I have a couple of engines with rings and so far haven't seen a nickles worth of difference in performance. They do seem to last longer before a rebuild but not anything most people would ever notice.

I favor ringed. When a rebuild is needed, your buy a new ring. In ABC, you buy a piston and liner - a lot more $s.

Paul

ABC breaks in easier and makes a touch more power, all else equal. Ringed lasts longer, especially if you idle alot.

I think you're asking the wrong question. Neither one is really "better".
I think the question you should be asking is which of the two
engines you listed is most appropriate for the plane you intend.

Both are good engines. But have somewhat different characteristics.

The Tower 75 is a screamer. Loves RPMs. Ideally suited
for something you want to go fast.

The GMS 76 while just as powerful seems happier turning
somewhat larger props at lower RPMs.

Maybe if you tell us what plane you intend this for we can give
you a better answer.

Mike Hammer

The planes I have in mind are the pulse xt 60 or the twist 60.

Yea, yea yea, jump all over me. I was referring to the manufacturing process where they don't have to machine in a piston groove, manufacture a ring and get it installed on the piston and then installed safely into the cylinder. ABC is a lot less fuss for the manufacturer hence cheaper to build.

That cheapness to manufacture works in the favor of the manufacturer but I'm not so sure it works in the consumer's favor.

. . .and yes I do have a couple of Jett's and I did cry when I forked out the greenbacks. (I did it none the less!) . . .(and glad I did!)

Making a ringed piston is ten times easer than a ABC one. The ring is there to do all the sealing so the rest of machining can have a lot more variables and still be ok. ABC has to seal slide with one part. If you look at the model machinest hobby, almost all use rings because they cant machine to the tolerance needed to make ABC; it takes some expensive machines.
I like ringed engines because they seem to last a little longer; ABC makes a little bit more power, but I would say maybe 3-5% more.