Engine not possible to rotate

[redvxcoupe]

Started to dismantle a 1800 TC engine from 1975 today....
I find piston 4 is rusted....or pistonrings has rusted in cylinder wall....

How do I hammer piston out? Was thinking of using 84.4mm overbore so I only need the block.

Any ideas? Managed to push out by hand piston 1, 2 and 3

Some time in the future I will overhaul my 1600 (matching numbers, Coupe and engine), 1975 engine which is quite rare, 80mm bore
This 1600 and my new 1800 is the same hight (need this because of Series 1 bonnet)

Tore

[Neil-yaj396]

If you top up the rusted bore with some diesel or other type of penetrating oil, and then let it sit for a week (or more) that might shift it. I wouldn't advise using any greater force than the wooden shaft of a hammer hit from the top.

[redvxcoupe]

Thanks.
Tested this but I have only left it overnight. Will leave it until next weekend and see if it works

[rossocorsa]

You can try to loosen it from the top but if it's tight I think you will need to tap it out from underneath because I'm not sure there's enough space to take them out through the crank case, a long piece of wood similar size to a hammer handle should help the right size will fit under the piston crown on one side obviously don't use brut force on the rods, limited risk of damage really as in this state the bore will be badly pitted and the rings will be well and truly stuck to the piston so a rebore will likely be the only way forward and the piston is probably scrap (although the piston might be ok it's surprising how little corrosion can stick them, it will be a game of patience and aching fingers to free off and remove the rings though!)

[lanciamad]

As suggested, i've heard of topping up the bore with diesel and leaving for as long as possible before. Couple of sharp taps with a block of wood in between normally moves most things. Good luck.