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Old 05-10-2014, 01:02 AM   #1
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Are these pistons useable?

I picked up a 3.4 from a shop who had removed it and taken it to bits. It looks like the crank and rods/piston assembly has been sat on the floor and has slightly marked the pistons...though I think some is engine use also.

On this one you can see the lighter areas where it looks like some coating has worn away? Also a few vertical scores though you cant feel them with a finger nail barely.


This one similar lighter areas with some deeper marks from the shop floor...schmucks!


This one similar




Ignore the grit and mess on them....they need a clean!

Can they be lightly cleaned up with fine emery, or are they paper weights?

Thanks
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Old 05-10-2014, 03:58 AM   #2
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IMO - If you're going through all the work in taking apart the engine, I'd make sure the pistons are pristine! I wouldn't touch them - but that's just me.
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Old 05-10-2014, 09:09 AM   #3
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Why was the engine torn down?
What do the cylinders look like?
Do the ring grooves, ring end gap, O.D., and piston pin bore meet spec?

That piston doesn't look so good to me but looks can be deceiving.
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Old 05-10-2014, 09:21 AM   #4
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What you are showing is not significant. Totally and properly cleaned that is nothing to be concerned with, IF they meet specs in terms of measurement. Careless handling for sure, but not an issue if they meet spec for size IMO. The big question is what would you be doing with them? The cylinders are critical and a simple inspection is not sufficient.

You WILL want to use new rings with those of course.
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Old 05-10-2014, 09:39 AM   #5
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Sorry yes I ought to have said I am intending to re-line the 3.4 and mybe re use these pistons.
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Old 05-10-2014, 07:45 PM   #6
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Those pistons have failed. One the iron coating has flaked off the next thing that happens is increased cylinder wear.

I have hundreds of good used pistons, we throw them away daily and never reuse them, even if they loo good.
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Old 05-11-2014, 08:33 AM   #7
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Thanks for all the input
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