hi all i have a 1900 cvh power engineering engine and recently had compression test and no 3 was down by half so took head off and checked valves and all ok then took no 3 piston out and cheched rings this may be a stupid queston but one of the rings is stuck in the piston and wont come out well not tried force but is this the cause of my compression loss

 

Could be mate, in my experience they should move freely round the piston.

 

yea thats my thoughts they should move but this one is stuck in the groove

 

I'd say that is your problem then.

 

Hows it stuck? seized or melted to the piston?

 

like its siezed in and only on 1 piston too

 

if it is stuck, this will hold it back from the wall of the bore resulting in a gap being created. Could be possible overboost where the pressure has forced the alloy of the piston down causing it to squash the ring.