Hello, I am farely new to the site. BUt I have a question. I recently got My 72 N600 started. Cars starts up find and actually drove it around the block. THE problem I have is that one of the cylinders has low compression. ONce has 125 the other 65. I figure the rings are stuck on the piston due to the fact that you can see smoke come out the oil cap when its off. I poor transmission oil into the cylinders to see whether that would help it but the oil drains into the crank case really quick. ON the other cylinder it doesnt. My question is whether there Is anyway that I can get the rings unstuck fromt he pistons without taking the engine apart. SOme type of chemical or anything like that. WOrst comes to worst I will take it apart.

You can try Marvel Mystery Oil or automatic transmission fluid, but it sounds like you already tried that. Maybe letting some sit, pouring in a little bit once or twice a day for a week or two, then change the oil and go for a drive. You may get lucky!

Sounds like you have a stuck or broken ring, how long has the car been off the road? I have a set of NOS pistons and rings if needed along with all the gaskets.

Search around and look for "KROYLL" pennetrant. Heat the pistons in the oven (when wifey isn't home) Soak the rings in it and try to pick/ligthly chisel at the ring gap. If that doesn't work, try and freeze them for a few days to 'soak' them.

I was given a set of barely used B16a Hi comp pistons just because the prev owner didn't know how to..

You can LIGHTLY take a jewelrs file to knock down any burrs after.

Errol

OOPps. I didn't read it completely..

If it's air cooled, (don't know too much at all of the earlyier cars) you may have broken rings/lands.

Errol

THanks for your help. I am already going to take it apart and see whether the rings are broken or seized onto the piston. Seems to have alot of oil build up on top of the piston just by looking thru the spark plug hole. THanks.

OIL? You sure? Stick a Q-tip in there (without dropping it) and see what it is.
Oil or gas diluted oil..
How long has it been running like that?
How many miles?

E

Its dry oil. I guess it was burning oil for some time before I bought the car and the guy i bought the car form said it was sitting for over ten years. SO i'm thinking the oil it use to burn gumed up the rings to the piston. I looked thru the spark plug hole and seems like dried up burned oil. I just tried right now some b12 chemtool in the spark plug hole. It says it works. SO i will try to start it tommorrow. If it didnt work I will get the engine apart and see whats going on with it.