ABC vs Ringed - RC Groups
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Jul 17, 2006, 04:36 PM
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ABC vs Ringed


Wich are the diferences between ringed and ABC engines? I kwon about the ring , what I mean are diferences in: power, maintenance, weight, performance, price, etc.

Wich one is the best?


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Jul 17, 2006, 08:50 PM
Registered User
Originally Posted by psantaana
Wich one is the best?
No such thing as "best".

All personal preference. Either one will be OK, and the life of each engine depends on how you treat her.
Jul 18, 2006, 01:40 AM
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downunder's Avatar
If you have two engines of the same brand where the only difference is one's ringed and the other ABC then there's no difference in performance. There's also no real difference in weight either but ringed would probably be slightly lighter only because it uses a steel liner instead of the slightly heavier brass. Much the same as an OS 46LA is lighter than the 40LA because it uses a thinner liner.

Maintenance is another thing though because that usually means when it's time to replace the worn parts. With a ringed engine you just replace the ring for maybe $10 or so but with an ABC you have to replace the piston/liner as a set for a considerable proportion of the new price of an engine. Both types will last about as long if treated right, which means enough oil and keeping dirt out of them (and never going lean ). However, ringed engines are much more dirt tolerant which is why they're more common in helicopters where they're always hovering close to the ground and kicking up dust. An air filter on an ABC will help it last longer but they're a good idea on all engines anyway.

An ABC can be flown almost straight out of the box (which doesn't necessarily mean it'll last as long) while a ringed engine needs a fairly careful and long running in to get the most from it before it's flown.
Jul 18, 2006, 11:16 PM
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To expound on what Downunder said. All things being the same there would be little difference in power. This is true for sport engines; say an engine that operates below 15,000 RPM. As one moves into higher performance engines the drag of the ring against the cylinder robs more and more power as the power band is moved higher in RPM. ABC construction allows the engine designer to increase the cylinder port area, as the need to support the ring past the ports is no longer an issue. There is still a need to support the piston but not a ring. This means for any given cylinder timing an ABC engine cylinder port could flow more fluid.

For sport use I would recommend ringed engines. As it is a lot less expensive to replace a ring and hone a cylinder than it is to replace a matched piston and cylinder of an ABC type engine.
For high power and/or high rpm engines an ABC piston and cylinder show some advantages.

P.S. I prefer AAC (Aluminium piston Aluminum Chrome plated cylinder) for performance engines.
Jul 19, 2006, 10:39 AM
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downunder's Avatar
Originally Posted by Konrad
P.S. I prefer AAC (Aluminium piston Aluminum Chrome plated cylinder) for performance engines.
Me too, as in my Enya 60X. But lately I'm starting to sway towards ceramic like Norvel uses.
Jul 19, 2006, 01:38 PM
Multi-Platform Pilot
barracudahockey's Avatar
Ringed engines are a bit more tollerent of poor tuning as well.

IMO its harder to burn one up, especially in helicopters.
Jul 19, 2006, 02:04 PM
AMA 754
BobRCnut's Avatar
I totally agree. The most durable and reliable engine I ever had was a Webra 40 ringed... it ALWAYS started easily, ALWAYS ran well, and the older it got, the better it ran. I used it in the same plane for nearly 5 years, in fun-fly, pattern, and off water. Unfortunately, a nose-to-nose midair collision treats both ringed and ABC engines with the same level of impertinence... R.I.P...
On the other hand, the most powerful engine I ever had (for its size) was an ABC... an MVVS 6.5 cc rear exhaust.. and it was also the best-idling engine I ever had.
Jul 30, 2006, 11:50 PM
Registered User
OK all you Webra experts, I need your help. I have an old Webra 40 RC Black Head 1022 w/ TN Carb. I took it out of a Kadet Sr. years ago still in running condition. I have a Tower Hobby Trainer 40 which I rebuilt for training purposes but I can't seem to draw fuel in to the carb to start the engine. Reading the old instructions didn't help so I have turned to the seasoned experts "on line". Do I putz with this or just go get a nice OS 40 and be done with the aggravation?
Jul 31, 2006, 12:52 AM
Suspended Account
I think you posted in the wrong area.
Fuel draw problems at the start are often tank related rarely an engine issue. Check your fuel line from the clunk to the spray bar. Make sure there is no kink through the firewall. You might want to test run the engine on an engine stand to eliminate the problem with that Tower trainer. Last with you fuel pump or fuel pressure device hooked up to the fuel nipple of the carb verify that fuel is flowing through the spray bar.
Nice and OS should rarely be used in the same sentence. Yes OS makes OK sport engines, but I have to ask why pay a performance price for a sport engine. By the way nickel should never be use in a model engine's cylinder fueled by alcohol. If you want to move up to a performance engine look to Nelson, Jett, YS, MVVS etc. If you want a sport engine take a good look at Enya, Irvine (pre OS), Webra.
OK, I know YS engine uses nickel, this just proves nobody perfect.

The above statement varies as price and value vary between locations. Your mileage may very.


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