Bent Piston Skirt

I

IHCScout78

Member
I seem to have bent the skirts on several of the pistons from the IH 345 I am rebuilding. Apparently happened from the piston flopping around on the rod while cleaning them up.

Anyone encountered this before? Is this repairable?

Pistons have sc on the top; z4235-4 cast inside. Made in usa, 41k and n or z (depends on which way is up) inside a circle cast inside. Any help on brand/type of piston?
 
I've never heard of that. They are bent out? You'd just about have to use them as a hammer.
One thought is that they saw a very high temp ans have lost all of their hardness. Normally they would fracture before bending much.
 
Yes; bent out.

When I put a straight edge on the piston, there is a sliver of light under it.

Worst piston is about .009 too wide at the bottom of the skirt, interference fit in the bore. Pistons are .040 over. Measure 3.912 just above skirt and 3.919 at bottom of skirt.

Engine was run out of oil before the rebuild. Pistons do not appear discolored. Think they lost the heat treat?
 
The oil is in large part responsible for cooling the piston.
Take a mallet and see what it takes to bend them back. It should take a hard whack to bend them.
If it were my build I'd 86 them. I don't know what you are trying to acheive.
 
Thanks Robert. I'll give it a wack:mad2:

trying for a basic, stock rebuild. Nothing special, but don't want to do it again any time soon.
 
Pictures of the piston attached. Gap to straight edge is visible in the picture.

I talked to an engine builder. This is a fairly common problem. He recommended your hammer trick, but with very light taps and tap, measure, repeat.

He also indicated don't try for perfect. As long as it fits in the bore and moves freely, heat and piston side load will do the rest.

Apparently these aftermarket pistons are not as robust as the IH originals.
 

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Interesting that it is a common problem but I have never experienced it..... Maybe I'm just easier on my parts. :lol:
if you load a piston into a bore that is tight or not fit correctly it will most likely score the bore. This is not my first rodeo and imo the "run it and it'll wear in method" is a bs recommendation... Sorry but sounds like the machine shop is an odd operation at best...
Hope it works out ok for you.
 
I am painfully aware that this is a self inflicted wound:icon_xp:

have you used zollner pistons before?

I have not seen this before either. I wonder if structural design of the zollners is slightly different.
 
No I have not at least non knowingly. I have used others lo cost pistons and even dropped the piston rod assembly on the piston crown badly enough to close up a ring land and the skirt was not damaged... I would suspect the piston integrity.
Zollner is an old American name that was bought my an asian company a while back... Who knows how their quality was.
 
Who made stock pistons for IH 345?

I found a posts on binder planet indicating it was zollner.

There are posts on just internationals indicating zollners were stock for various engines, and one photo showing the zollner plant next door to IH in fort wayne.

The engine I am playing with was a genuine IH renewed engine purchased in 1999. They might have used stock pistons.

Inquiring minds want to know.
 
Hammering the bent skirt did not work. It takes a series of good wacks with a soft hammer to move the skirt even a few thousanths. I had hoped the tab would bend back into the original shape, but the piston distorted.

Not wanting to shove a square peg into a round hole, I have ordered new pistons:icon_lol:
 
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