[obosse]

I have a big block chevy that went under water in huricane ketrina,It was a complete rebuild. I have just gotten around to it now. I HAVE THE HEADS off,pan .rod,mains,caps off. It is rusty in the cylinders,and looks like silt around the pistons, Anyone know of a way of freing it up? I cannot get the crank out because the piston pins are feozen in the pistons,and wont move!

 

[T-bucket23]

Marvel mystery oil usually will help things along. Just keep soaking it. You may have shot yourself in the foot by disconnecting everything. The usual method is to soak the cylinders and rock it back and forth using the crank bolt until it frees up. Patience is the key. SOme people have used automatic transmission fluid as well. Where you already have the heads off you can gently tap the tops of the pistons with a hammer and block to help the oil penetrate. You are not trying to move the pistons, just setup a little vibration to help the oil penetrate.

 

[old76c10]

first thing i would do since you already have it tore down is get a good pressure washer and clean it up get all that silt out of it...its already been under water what is a little more going to hurt?flip it over so you can get all underneath the pistons then use some pb blaster under the pistons coatin the bores good flip it back over and fill the bores with marvel mystery oil or tranny fluid let it set over night and then try bumping the pistons with a block of wood dont beat them just a little bump it may take 3 or 4 days of this but they should come on out