Replace everything it not ??
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Joined: Apr 2017
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From: Raleigh nc
Replace everything it not ??
Im fixing a base gasket leak and found this scuffing on these pistons.. They are the s&s 4 inch bore pistons that bolt on a 96 inch case . They have about 8.K miles on them and am considering replacing them and the jug . These are really more like scuffs and dragging a finger nail across them , you cant feel them ..What do yall think caused these marks and would you re-ring the piston , hone it and run it ?? The cylinder looks great
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Joined: Apr 2017
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From: Raleigh nc
Im fixing a base gasket leak and found this scuffing on these pistons.. They are the s&s 4 inch bore pistons that bolt on a 96 inch case . They have about 8.K miles on them and am considering replacing them and the jug . These are really more like scuffs and dragging a finger nail across them , you cant feel them ..What do yall think caused these marks and would you re-ring the piston , hone it and run it ?? The cylinder looks great
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From: poway
OK so you have later twincam cases say 07 to 10-11 and a SnS 110 kit.
Well, I wouldn't use calipers to measure the pistons. Buy a micrometer. You say you have snap gauges?
As far as the pistons go, they may be OK but it looks like the cylinders weren't clean or oiled when installed on the pistons originally. The scratches look more like the lead in edge on the cylinder spigot had a burr on it that scratched the pistons. There may be a small ding or simply some foreign material that put that one scratch, Need to look at the cylinders. I guess you could run a fixed hone through the cylinder real quick to get an idea of the condition of the cylinder spigots. They may be damaged which caused the scratches.
Well, I wouldn't use calipers to measure the pistons. Buy a micrometer. You say you have snap gauges?
As far as the pistons go, they may be OK but it looks like the cylinders weren't clean or oiled when installed on the pistons originally. The scratches look more like the lead in edge on the cylinder spigot had a burr on it that scratched the pistons. There may be a small ding or simply some foreign material that put that one scratch, Need to look at the cylinders. I guess you could run a fixed hone through the cylinder real quick to get an idea of the condition of the cylinder spigots. They may be damaged which caused the scratches.
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From: san antonio
I have used pistons in similar condition after measuring to insure they were in spec but they were going into freshly bored cylinders, so no cylinder wall scratches and a know true bore. I would measure everything for fitment and, if necessary, follow Max's suggestion to check/clean up the cylinder walls and if all turns out to be in spec, no spigot damage, put her back together. JMHO
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Thread Starter
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Joined: Apr 2017
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From: Raleigh nc
OK so you have later twincam cases say 07 to 10-11 and a SnS 110 kit.
Well, I wouldn't use calipers to measure the pistons. Buy a micrometer. You say you have snap gauges?
As far as the pistons go, they may be OK but it looks like the cylinders weren't clean or oiled when installed on the pistons originally. The scratches look more like the lead in edge on the cylinder spigot had a burr on it that scratched the pistons. There may be a small ding or simply some foreign material that put that one scratch, Need to look at the cylinders. I guess you could run a fixed hone through the cylinder real quick to get an idea of the condition of the cylinder spigots. They may be damaged which caused the scratches.
Well, I wouldn't use calipers to measure the pistons. Buy a micrometer. You say you have snap gauges?
As far as the pistons go, they may be OK but it looks like the cylinders weren't clean or oiled when installed on the pistons originally. The scratches look more like the lead in edge on the cylinder spigot had a burr on it that scratched the pistons. There may be a small ding or simply some foreign material that put that one scratch, Need to look at the cylinders. I guess you could run a fixed hone through the cylinder real quick to get an idea of the condition of the cylinder spigots. They may be damaged which caused the scratches.
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From: deland,florida
torque plate & check the cylinders with a bore gauge.pistons look like they were inatalled dirty or your getting debris from somewhere else (could be the start of rod bearings going south) dosnt look like S&S stuff though,they use a 2mm oil ring and the oil rings look bigger than that.
