IC Engines and compression

[dam74]

I no longer own an IC helicopter and at the time I never got the thing running due to the two second hand engines I tried not starting. What I wanted to know is with car engines I have used compression gauges to measure how much compression there is on each cylinder. Are there any ways of measuring RC engines to ensure that the recommended compression is achieved. Or do most people just know by feel??

[derrick]

Feel it

[bigbas]

Really have not heard of a compression gauge that will do a model nitro motor would have to have an extremely small adaptor to fit i have them for petrol motors but you just feel a nitro motor if no decent compression just replace ring or piston and liner imho bas

[dam74]

What I noticed with David Drew's 37 is that the groove that the piston ring sits in has a burr so that it gets stuck and doesn't expand outwards around the circumference of the piston. Some parts it is fine and does as it's suppose to and expand. Other parts there seems to be a slight burr and to get it to sit into the groove you have to push on it hard and as a result it doesn't expand back. Would you recommend cleaning the groove with a dremel with a polishing disk?

[jamiem]

clean it by hand, using a dremmel could be far too vicious!

[dam74]

clean it by hand, using a dremmel could be far too vicious!

Jamie I've tried scraping the varnish (for those who don't know - burnt on non-synthetic lubrication eg. castor) using my finger nail and a modelling knife. There still seems to be a fair amount of stickiness to the piston ring.

[bigbas]

Try using a old piston ring to clean groove!!!!

[Boggy]

an overnight soak in nail varnish remover works wonders Daryl