Removing a Really Stuck Piston

I had to smash one out with a sledge hammer, with the block sitting on a pallet once.

Needless to say, it didnt go back in.

That engine now has over 12,000 miles on it and was still producing loads of acceleration at over 130 mph at the Nurburgring 2 years ago, in my Silver FHC.

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Well I saw but was skeptical about flaming my engine but willing to try some dry ice but in the meantime , while soaking was having questionable results , made some custom wood blocks and did some rotational blows from one side to the other and finally got my final piston out just in time for some Thanksgiving Turkey Here are pictures of the wooden helpers.


Hello John,
What would probably work better than Dry Ice alone, would be to do the following:

  1. Put a bead of plasticine around the interface of the circumference of the top of the piston and the bore.
    Step 1 is probably not necessary, given that the rings are likely corroded in the piston’s ring grooves, but the plasticine is to stop any Acetone that may get through the holes in the Oil Ring groove and past the other rings, from leaking out.

  2. Invert the Block (top of pistons facing down)

  3. Use enough Acetone to fill the cavity of the inverted pistons

  4. Drop Dry Ice into the Acetone until all reaction ceases

Dry Ice sublimates at a temperature of -78.5°C and as Acetone has a freezing point of -95°C, it will stay in the liquid form.

  1. When all reaction with the Dry Ice has ceased, the Acetone will be as a temperature of circa -78.5°C

  2. Pour the cooled Acetone into Piston Cavities.

Have all tools ready to take whatever action you have planned when the Pistons have cooled. Make a small ladle to scoop most of the cold Acetone out of the Pistons, as it may prove too cold to suck out with a large syringe.



I love it! Much more scientific than the big hanmmer method!!