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Scaratches on pistonīs and sleaves.... WHY ???

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Old 09-30-2010, 04:24 PM
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What did you hone that block with? If you used a drill and a hone, it looks like you went too fast with it and didn't use an up and down motion. I don't see any crosshatching.

In any case, the block looks like the cylinder walls are now out of round. You could probably have it machine honed with more precision and get the surface looking better. At this point though, you would need oversized pistons. Better do it right than to just throw everything back in there.
Old 09-30-2010, 04:32 PM
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Originally Posted by killernoodle
What did you hone that block with? If you used a drill and a hone, it looks like you went too fast with it and didn't use an up and down motion. I don't see any crosshatching.

In any case, the block looks like the cylinder walls are now out of round. You could probably have it machine honed with more precision and get the surface looking better. At this point though, you would need oversized pistons. Better do it right than to just throw everything back in there.
the pistons i have is 4.005", but the next size up is 4.010", the question is if that is enough to loose these marks,
and should i let the mahcine shope hone it to 4.010 or can it be bored .005 out

would a 4.020" not be bit to much for the LS2 donīt wante to loose the strength out the block, plans are NOS...
Old 09-30-2010, 08:56 PM
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Those marks should come out at .005 more. You should be able to have your machine shop check the bore size, if it measures under 4.0075 in the shadow it should clean up. No problem for that low amount of material to be honed out with a Sunnen CK type machine.

Kurt
Old 10-01-2010, 12:39 AM
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I had the same problem. 4.000 stroke Callies Compstar crank in a 383 LS1. Measured my piston to wall clearance at over .007" when the piston calls for .0025" The engine had less than 5k miles and had horrible piston slap knocking so I tore it down and found this.
https://ls1tech.com/forums/generatio...clearance.html
Attached Thumbnails -img_1515.jpg   -img_1519.jpg   -img_1511.jpg   -img_1527.jpg   -img_1528.jpg  


Last edited by 89L98T56; 10-01-2010 at 12:47 AM.
Old 10-01-2010, 03:18 AM
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Originally Posted by 89L98T56
I had the same problem. 4.000 stroke Callies Compstar crank in a 383 LS1. Measured my piston to wall clearance at over .007" when the piston calls for .0025" The engine had less than 5k miles and had horrible piston slap knocking so I tore it down and found this.
https://ls1tech.com/forums/generatio...clearance.html
hi

wow.... i see iīm not the only one here unlucky....


Wiseco 4.010" pistons what should the blockīs bore size be at.
Should the bore size be 4.0100" accurate ?
wouldnīt it be smarter to purchase the pistons first and then bore the block out whith the piston on hand to get it 100% right...
should the clearence be .002-.004 there too.

Baezi
Old 10-01-2010, 09:31 AM
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Wiseco has no shelf pistons at 4.010 but they will do a custom. I would hone it to get round first if you want those shadows gone and then order pistons when you know what will clean up.
Old 10-01-2010, 10:46 PM
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Looks like it's been over fueling through a bad tune, washing the bores.,
Old 10-02-2010, 03:22 AM
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Looks like someone doesn't know SHEEET about fitting pistons! NOWAY fuel washed away .0075..............off each pistons EQUALLY and PERFECTLY. Face you got hosed! Go do it yourself this time and do it right. Find a good machine shop and YOU inspect the work before it gets put together. BE SURE to follow the piston manufacturer clearance specs.
Old 10-02-2010, 03:20 PM
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Originally Posted by HotSilverBird
Looks like someone doesn't know SHEEET about fitting pistons! NOWAY fuel washed away .0075..............off each pistons EQUALLY and PERFECTLY. Face you got hosed! Go do it yourself this time and do it right. Find a good machine shop and YOU inspect the work before it gets put together. BE SURE to follow the piston manufacturer clearance specs.
sounds like someone doesnt know SHEEET about machining, or engines for that matter.

fuel does not wash away the metal, fuel washes away the oil coating on the cylinders and pistons, then the piston has nothing to ride on, and destroys the cylinder wall and piston.
Old 10-02-2010, 06:32 PM
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Originally Posted by bww3588
sounds like someone doesnt know SHEEET about machining, or engines for that matter.

fuel does not wash away the metal, fuel washes away the oil coating on the cylinders and pistons, then the piston has nothing to ride on, and destroys the cylinder wall and piston.
Perfectly in every cylinder BULL SHEEEET
Old 10-03-2010, 10:39 AM
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Originally Posted by HotSilverBird
Perfectly in every cylinder BULL SHEEEET
yes, unless you have a cylinder imbalance issue. each cylinder is getting the same amount of fuel. it WILL wash away the oil on every cylinder and cause the same wear on every cylinder.
Old 10-03-2010, 06:23 PM
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you'd have to be a moron to not notice a 9:1 afr

looks to me light piston to wall clearance was too tight. either way, take it to another shop.
Old 10-03-2010, 08:14 PM
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Originally Posted by bww3588
yes, unless you have a cylinder imbalance issue. each cylinder is getting the same amount of fuel. it WILL wash away the oil on every cylinder and cause the same wear on every cylinder.
Bs might wash the cylinders down but it aint gonna machine um LMAO
Old 10-03-2010, 08:57 PM
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you can hone it get new pistons new rings and re file fit also make sure that you have enought piston to wall normaly the reason this happens is not enought piston to wall
Old 10-04-2010, 02:24 AM
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Originally Posted by rem308winvtr
you can hone it get new pistons new rings and re file fit also make sure that you have enought piston to wall normaly the reason this happens is not enought piston to wall
iīm not sure if that was the reason here....

but either way it will be done right this time.... iīm waiting for the new set of pistons

thanks a lot guys

Baezi
Old 10-04-2010, 09:59 PM
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Originally Posted by rem308winvtr
you can hone it get new pistons new rings and re file fit also make sure that you have enought piston to wall normaly the reason this happens is not enought piston to wall
In my situation it was too much PTW.



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