Re-using old pistons

[1987stangman]

I see people all the time selling used forged pistons and rotating assemblies from forged piston 5.0L's all the time. My question is, can you really re-use them in a differnt 5.0L block? I know that I overhauled my 87' motor with new rings and bearing and a cyl honeand everything worked out perfect but one would think that using using pistons from another motor in another motor would not be a good idea. School me on it.

 

[Chrome_Rust]

I just rebuilt the 4cyl in the wife's notch over the last month. 1 piston had a hole in it. I used a piston from an engine that was lying around. Honed the cylinder walls and installled new moly rings. put 300 or so miles on it since rebuild, and have had no problems.

 

[HotFox]

Yes I would just suggest a good look over them for blemishes, cracks etc. I would mic or have a machine shop mic each skirt to make sure none are collapsed.

If you are fitting them to the block your machine shop would mic them any way to hone the block for the correct piston to wall clearence.

Scott

 

[1987stangman]

Yes I would just suggest a good look over them for blemishes, cracks etc. I would mic or have a machine shop mic each skirt to make sure none are collapsed.

If you are fitting them to the block your machine shop would mic them any way to hone the block for the correct piston to wall clearence.

Scott

I'm not planning on doing this, I just wanted to know if anyone else has ever done this and what the results in longivity are. My thought was your comment, piston to wall clearance. One would think that a piston with over 100K miles would not be usable in another engine block. Thanks for the replys everyone.

 

[90mustangGT]

From 87-92 (I think) the pistons were forged. They are pretty tough. If the bore gets too big for the piston, it may rock a little inside that bore causing excess wear and can make it hard for the rings to properly seal. So what CAN happen is you spend the time and money to on the engine to "rebuild" or refresh it and then it just doesn't come out right. A refresh is a poor man's rebuild, and is often done more often to race engines. Such as you have a motor that is good, but has a little excess leakdown, (more than 10% is excessive for a race application) so they rebuild it be just putting in new rings and berrings with a ridge reem and re-hone on the bores. Works fine for a good engine, but take a wore out engine, it may give it some more life but won't be as good as a rebuild.

 

[foxmustangman]

Till 1991

 

[Tanus]

I wouldnt reuse pistons on a performance rebuild, crank and rods yes, pistons no