Seized Piston

[moldman05]

I bought a 54 Desoto hemi engine last spring at a car show. It would not turn so I pulled the plugs and poured in oil and trans fluid and let it soak. Today I pulled the pan, all the bearings look good, no water or rust just oil. Number 2 piston won't move. I tried more lubricant from the bottom of the cylinder, I heated piston from bottom with torch, beat every which way with blocks of wood, and tried turning the piston with connecting rod, but no movement. Any thoughts on what to do ? The engine is really clean on the inside and the bottom end has been rebuilt so I'd like to get it running without dissassembly and rebuild. Thanks for any help.

 

[rodney eppes]

I've never worked on such, but I remember my brother freeing up a 36 Chevy, back before WD40, ever came out. He pulled the head, & soaked the pistons probably with kerosene as he beat on them with wooden blocks. After a week, it broke loose. WD 40, is advertising a new penertrant, just for rust. Haven't looked 4 it yet. I'm guessing you'd be better pulling the head. Unbolt the rod, & see if the rest of the pistons, will move. If they move, rotate the crank away from # 2, & keep soaking, & beating, downward. You might be better off, trying to heat the clyinder, than the piston. Just don't overdo it. It should be the rings, that are rusted to the cylinder.
Just my nickels, worth!

 

[ord.sgt.26NC]

yea,I also say pull the heads and see what you got. I picked up a flathead v8 one time for a project and it was siezed so bad,I had to break all the pistons up to get them out. PB blaster might work better for you.

 

[6BangBronk]

I don't know this motor but this should still apply? Marvelous Mystery Oil. May not need to pull heads. Fill cylinders through spark plug holes and let it set for a day. Then use breaker bar and manually turn back and forth at balancer pully. Don't apply much more than the balancer pully bolt is torqued. If you can get it to move just a fraction, then you can unfree it by going back and forth and repeating the mystery oil. Be sure to drain the pan thoroughly before refilling with oil.
I suggest keeping the pan on and filling enough with MMO so that you can prime the motor to reach all internals by pulling the dizzy and using a drill and oil pump shaft tool (you can make your own using correct socket and such. Be sure that it is turned in the right direction? Again, I wouldn't know this motor if it fell on me?