how do i remove seized pistons from cylinder head CA77 t-II

[teazer]

patience, heat and penetrating oil. repeat frequently.

Or as I read in a post recently (somewhere else) - it takes lots of patients to move rusted parts. Maybe he was a doctor ;-)

[ricksd]

I recently did this on an engine that had been sitting in a cornfield without carbs or exhaust for 20 years- it can be done. Beating on the pistons is not too likely to work- if you do, remove the lower crankcase so the pounding isn't transferred to crankshaft bearings.
I used the top of a 2-leg puller, pushing down on the piston and pushing up on tubes beneath nuts on the crankcase studs- penetrating oil and a little twist a day and it eventually came loose. I thought it might be necessary to push on both pistons simultaneously, but tried 1 at a time and it worked fine. If I do it again, I'll pull the studs and make a plate that bolts into the crankcase, covering both cylinders, with a big bolt pushing on an aluminum plug on top of each piston. One of my pistons was at bottom dead center, so I couldn't try wedging the barrel up from the crankcase, but doesn't sound too promising anyway. A friend bolted a plate over the cylinder, tapped a grease zerk, and used a grease gun to push the piston down- sounds like a good scheme to me- lots of pressure evenly distributed over the piston top.
I found heat to be a waste of time- the rings are probably rusted to the liner, so even if you did cause some expansion, the rings would just 'open up' and expand with the liner instead of breaking free.
So, my advice- if you're in a hurry use the puller as a 'pusher', but the grease gun/plate would be my first choice- I'm going to make one, assuming I'll need to do this again someday.
Rick

[real_psyence]

Good call on the grease gun. I had seen that reference elsewhere, but couldn't figure out a clean way to do it. Most of the time they call for making a zerk adapter from and old sparkplug, and I think that would work,but you'd have to use the top crankcase cover to hold everything together after you made sure the valves were closed (removing the rocker arms/cams?)

[maia]

I used little hardwood wedges driven in between the cylinder base and crankcase and pored in enough liquid wrench to cover the pistons and every once in a while I would tap the piston crown and drive the wedges in a little more. Three weeks later ping! and it moved about 1/16 th of and inch and after that it was easy.

[maia]

I used little hardwood wedges driven in between the cylinder base and crankcase and pored in enough liquid wrench to cover the pistons and every once in a while I would tap the piston crown and drive the wedges in a little more. Three weeks later ping! and it moved about 1/16 th of and inch and after that it was easy.