Piston Ring / Liners

[TedAllen]

I'm a bit stuck!....pun intended.
I'm currently dismantling an engine, kindly given to me by the Honourable Member for Runcorn.
It's all standard and there's a fair amount in it to re-cycle.
So, I've set about building a spare engine for the Javelin, using the crankcase , liners and pistons.
I have two of the pistons out of the engine and also out of the liners but I'm damned if I can shift the rings.
I've tried all the usuals over the last couple of weeks....Plus Gas, Coca Cola, Heat, Hydrochloric Acid, DP60, Carb cleaner, etc.

Heating the liner with the Oxy/Axy around the area of the rings made no difference.

They don't want to know. I assume they're stuck with carbon deposits, there's not much rust in the liners where the pistons were.
Any ideas ? I don't want to damage the pistons but I can sacrifice the rings. I also have 2 liners, complete with pistons, stuck in the block. I don't want to hammer the liners out with a drift as they are undamaged up to now.

I'd be grateful if anyone has any secret recipe handed down through the family.

Ted

[Tim Neville]

I don't want to damage the pistons but I can sacrifice the rings.

. I've always found that if you can get and edge of a good punch onto the end of a ring, with careful tapping, once the ring starts to move the rest of it easily breaks off from the carbon adhereing to it. More often than not it can be done without breaking the ring. A really strong solution of Caustic Soda will soften carbon, but you can't leave it in contact with the aluminium for too long. Also with really tricky ones, a repeated cycle of heating and then cooling in a pre-cooled tin in the freezer, will usually ease off two dissimilar materials stuck to each other. I used this technique on an old magneto that I had to repair, where a corroded and oxidised piece of ali was stuck into a bakelite moulding. Obviously I couldn't heat up the bakelite too much without damage, so I warmed it all as much as I could with a hot air gun and then put it in the freezer. After half a dozen cycles of this, the ali part came out!

[TedAllen]

Hi Tim.
My next thoughts were heat, I found some tips on a couple of websites earlier, I think Buell motorbikes was one.
The simplest seems to be to boil up the piston in water in to expand the alloy, then tap the ring all the way round with a hammer..There's not much of a gap to get a drift in.......I've tried that. I have a scrap piston with stuck rings which is quite good to experiment on. I had some thoughts on Caustic Soda. We had the oven cleaned by a specialist firm a couple of years ago and I have it mind to phone them on Monday to see what can be used.
I got the remaining two pistons out today, without the liners coming out. I thought two liners had come out but there are three still in the crankcase so I must have had a spare one on the bench.

I have a spare set of STD pistons so it might be a case of using them and putting the seized ones into long term soaking.

I was in a plumbers merchants yesterday and saw an aerosol product called, I think, Freezeshock or Iceshock which looked interesting. It's used for freeing rusted items in the plumbing trade. I'll have another, proper, look when I'm in again.

I've still got a screen here, Tim, if you want it. It's not in my way, it's snuggled up to my spare.

[Forumadmin]

I would discard any piston with a stuck ring; because something not too desirable has caused it to stick. I would hone or rebore the liner as well.