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KTL KTL is offline
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Join Date: Sep 2000
Location: Frankfort IL USA
Posts: 15,776
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I bought a set of pistons and cylinders from a low mileage '85 3.2 a few years ago. I wanted only the cylinders and figured I could re-sell the pistons. Once I got them cleaned up (removed the carbon off the piston crowns) I found smiley marks on the pistons. Point being is somebody zinged the engine a bit and then drove it awhile longer to cover up the marks with carbon. Even though the pistons had been apparently lightly tagged by the valves, the piston skirts didn't show any major problems because of it. I would have expected the skirt to show some significant side wear/scuffing due to the valve contact causing it to cock in the cylinder. Nope.

It was very easy to massage the smiles out of the piston top and blend it in. The amount of material you remove is a minimal amount and does not affect the balance. You'd be surprised how much material you can remove and it still doesn't amount to a major amount of weight. Reason I say this is because a few years ago I balanced some pistons by removing material under the crown. One piston was not from the original group of pistons and weighed quite a few grams more. I was surprised how much aluminum debris I created to get that piston lightened enough to be within range of the other 5 pistons.

I know the feeling of excitement. Been there. Although mine was a bit less feeling giddy and feeling more sick

Engine Bearing Failure- Disassemble Heads Too?
Kevin L
Present: '86 Carrera, '79 911SC widebody conversion rolling racecar shell
Past: '87 Carrera
Old 11-03-2017, 08:19 AM
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