Removing frozen piston ring
 

I've got a set of 906 pistons that I am planning to sell. Today when I went to do the final inspection I found that I could not remove the two top rings from one of the pistons. They seem to be frozen in place.

I want to preserve this piston and avoid damaging it since it is so rare. I need some advice on how to remove the rings without damaging the piston.

Can anyone help on this??

PB Blaster? I'm no expert.

Tom:

Soak it overnight in carb cleaner. That usually works.

I would think heating it and then tapping the ring with a wooden mallet would free it up.

after soaking it, tap the end around with a small punch, real lightly.

"I would think heating it and then tapping the ring with a wooden mallet would free it up."

If there's carbon build up, follow Steve and John's suggestion of soaking in carb cleaner. If it's clean, a variation of Robert's suggestion is to dip the inverted piston in some heated motor oil to expand AND lube the ring lands.

Let's hope there's carbon holding the rings in place. Is there a chance the piston was dropped? That can cause the ring lands to tighten up. Ring side clearance should be max. .004".

Sherwood

soak in carb cleaner for a bit as everyone stated above, then transfer the piston into a pot of boiling water for a few minutes. the ring will free right up. it'll be hot so be careful.

Will the carb cleaner attack the aluminum at all with prolonged exposure or discolor it?

Cheers

it won't attack the aluminum, but if you leave it in for more than 24hrs, some will turn the aluminum dull. clean but dull. the GUNK company makes a neat little gallon sized can of cleaner with a removeable strainer that you just dip the parts in and seal the can for awhile. it does turn it a little dull, but wiping the parts afterwards with soapy water and a clean lint free rag rings back the natural finish to the parts.