Rovan 45cc motor problem

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Mick Boomer said:
Friction is why. The first year of the rovan 45 were actually decent. They were single ring. The dual ring 45 sucks and gets hot.
You can actually make these cheap engines run well. You just have to dissemble them to check for shavings -bearing or gasket errors.
Click to expand...
I can't see how the second ring is going to generate enough friction to cause the engine to overheat without tell tail wear signs on the cylinder. That would be a lot of extra tension, and it would go away as the engine wears in. Possibly it lowers dynamic compression enough to avoid some heat build up, or another factor, but it's not the second ring causing too much friction. If anything it would help to transfer more heat to the cylinder.
 
🤷🏿‍♂️ First version ran great. Second version double ring trash ran hot. Wonder why taylor rc dosent run double rings🧐
For that matter might as well run 4 rings if friction isnt a factor🤷🏿‍♂️
 
Many, many 2 stroke engines run 2 ring pistons. There's more they changed then just the nimber of rings, I quite assure you of that. To generate the amount of heat needed to overheat an engine from adding a ring would be huge, like wear out the cylinder hardly able to turn the engine over amount of friction. I'd wager you're loosing a good bit of compression from removing the second ring. Has nothing to do with friction.
 
I'm the one who brought up the problem with this engine. The Rovan 45cc seems to be more prone to seizure when the accelerator is turned off from high revolutions. I'm going to try expanding the effective range of the throttle stopper and opening up the low speeds more.
 
Mick Boomer said:
Friction is why. The first year of the rovan 45 were actually decent. They were single ring. The dual ring 45 sucks and gets hot.
You can actually make these cheap engines run well. You just have to dissemble them to check for shavings -bearing or gasket errors.
Click to expand...
Piston rings actually transfer heat from the piston to the cylinder wall to help cool the engine. Although that extra ring adds a bit of friction, it's not going to overheat an engine if said engine is properly designed, manufacturered and tuned properly. My two ring ported chainsaws don't run any hotter than my single ring ported saws.
 
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