3.905 cylinder, might need a hone job...
02-24-2013, 02:35 PM
#1
3.905 cylinder, might need a hone job... I have a 2004 ls6 shortblock 3.905 bore diamond pistons, total seal (steel top) rings..
I noticed a few light vertical scratches in a few of the cylinders, And the rings are new only 2 start ups on them after installed....
Im thinking either
a- rings were not filed fitted correctly
b- some dirt or contaminate got in and did that
either way Im going to get it checked out this week at a machine shop for an opinion..
One you can kinda hang a nail on, and the others you can just slightly feel it with your nail.
Ok my question is if an hone will clean it up, since I'm already at 3.905 thatll take me closer to 3.910... Can you just get new piston rings and file fit to the new bore size or will I need larger pistons?
Im trying to mentally prepare myself for what to expect.
I noticed a few light vertical scratches in a few of the cylinders, And the rings are new only 2 start ups on them after installed....
Im thinking either
a- rings were not filed fitted correctly
b- some dirt or contaminate got in and did that
either way Im going to get it checked out this week at a machine shop for an opinion..
One you can kinda hang a nail on, and the others you can just slightly feel it with your nail.
Ok my question is if an hone will clean it up, since I'm already at 3.905 thatll take me closer to 3.910... Can you just get new piston rings and file fit to the new bore size or will I need larger pistons?
Im trying to mentally prepare myself for what to expect.
02-24-2013, 02:52 PM
#2
On The Tree
Join Date: Aug 2012
Location: Dayton, TX
Posts: 113
Likes: 0
Received 0 Likes
on
0 Posts
2 start ups.......this may be out there, but I wonder if you could hit a few times with an hone tool from the parts store and see if that will clean up before taking it to the machine shop? If everything is still in tolerance I dont see why you couldnt re-use those rings or just start with a new set. If it doesnt work then you could take it to the machine shop
02-24-2013, 03:29 PM
#5
On The Tree
Join Date: Aug 2012
Location: Dayton, TX
Posts: 113
Likes: 0
Received 0 Likes
on
0 Posts
Its easier than you think. Get a high speed cordless drill and go up and down as fast as you can. You can use some sort of straight edge sticking up off the deck as guide to keep it straight. If that scratch isnt deep it should clean right up. You just want to do it just enough to get a rough cross hatch. As far as how far you can go if you hone...measure you piston to cylinder wall clearence and check that against the tolerance. Good luck. I feel for you
02-24-2013, 04:02 PM
#6
ok Ill keep that in mind... If i bore a 5.3 out to 5.7 (3.905) I can reuse this rotating assembly and swap it right in correct? and get new rings for it and call it a day?
This might be the reason to switch to iron since i wanted to boost this motor to 17-20 psi
This might be the reason to switch to iron since i wanted to boost this motor to 17-20 psi
02-24-2013, 04:27 PM
#7
On The Tree
Join Date: Aug 2012
Location: Dayton, TX
Posts: 113
Likes: 0
Received 0 Likes
on
0 Posts
I know the same sized crank and rods are used on the 5.3 ls1 and 6.0. But I dont know if they used different sized journals on the crank in the ls6 or not?? I dont see why they would.
Trending Topics
02-24-2013, 04:36 PM
#8
On The Tree
Join Date: Aug 2012
Location: Dayton, TX
Posts: 113
Likes: 0
Received 0 Likes
on
0 Posts
02-24-2013, 04:46 PM
#9
same journals on both cranks. ls1 cranks are balanced for the pistons thats about it. if a piston weighs in >10 grams of each u can use a 5.3 crank. as far as putting the rotating assembly in an iron block. yes u can 
ls6 cranks are balanced different and will need rebalancing since theyre balanced for the beefier rods and pistons.
ls6 cranks are balanced different and will need rebalancing since theyre balanced for the beefier rods and pistons.
02-24-2013, 04:54 PM
#10
On The Tree
iTrader: (3)
Join Date: May 2010
Location: Ga
Posts: 149
Likes: 0
Received 0 Likes
on
0 Posts
If you can hang a nail on it, it's probably closer to .003" or more would be my best guess. It sucks but about the best you can do is disassemble and check it out but if it as is you say, I'm guessing you're going to have to let the machinist hone it. Sucks I know.
02-24-2013, 05:11 PM
#11
If you can hang a nail on it, it's probably closer to .003" or more would be my best guess. It sucks but about the best you can do is disassemble and check it out but if it as is you say, I'm guessing you're going to have to let the machinist hone it. Sucks I know.
02-24-2013, 05:14 PM
#12
same journals on both cranks. ls1 cranks are balanced for the pistons thats about it. if a piston weighs in >10 grams of each u can use a 5.3 crank. as far as putting the rotating assembly in an iron block. yes u can ls6 cranks are balanced different and will need rebalancing since theyre balanced for the beefier rods and pistons.
ls6 cranks are balanced different and will need rebalancing since theyre balanced for the beefier rods and pistons.
02-24-2013, 05:15 PM
#13
the just 2 start ups is irrelevant, damage is done.
Another thing that come to mind, is check the pistons if... or how much the problem did damage to them... the skirts. You could prep another block and put your parts in it (with new rings) If you can find another block std bore cheap. ($1-200?) I friend or somthing? I know now a days a deal like that is not easy.
Cleaning that block up will probably take more then you should run the pistons in, (.005+ wall clearance) it will run, but getto and hack.
If it dose clean up at 3.907 you should get new pistons for that size ($600) and you would have to have it rebalanced for that. Never used any 3.910, you can for some low power stuff I know stock class guys that do that. The piston cost more too, then a shelf 3.905/3.907 commons. Just somthing to look into, if the machine shop is at fault or anything, or they will prep another block cheap, that needs less machine work. It might come out better for you, god luck,
Another thing that come to mind, is check the pistons if... or how much the problem did damage to them... the skirts. You could prep another block and put your parts in it (with new rings) If you can find another block std bore cheap. ($1-200?) I friend or somthing? I know now a days a deal like that is not easy.
Cleaning that block up will probably take more then you should run the pistons in, (.005+ wall clearance) it will run, but getto and hack.
If it dose clean up at 3.907 you should get new pistons for that size ($600) and you would have to have it rebalanced for that. Never used any 3.910, you can for some low power stuff I know stock class guys that do that. The piston cost more too, then a shelf 3.905/3.907 commons. Just somthing to look into, if the machine shop is at fault or anything, or they will prep another block cheap, that needs less machine work. It might come out better for you, god luck,
02-24-2013, 05:21 PM
#14
the just 2 start ups is irrelevant, damage is done.
Another thing that come to mind, is check the pistons if... or how much the problem did damage to them... the skirts. You could prep another block and put your parts in it (with new rings) If you can find another block std bore cheap. ($1-200?) I friend or somthing? I know now a days a deal like that is not easy.
Cleaning that block up will probably take more then you should run the pistons in, (.005+ wall clearance) it will run, but getto and hack.
If it dose clean up at 3.907 you should get new pistons for that size ($600) and you would have to have it rebalanced for that. Never used any 3.910, you can for some low power stuff I know stock class guys that do that. The piston cost more too, then a shelf 3.905/3.907 commons. Just somthing to look into, if the machine shop is at fault or anything, or they will prep another block cheap, that needs less machine work. It might come out better for you, god luck,
Another thing that come to mind, is check the pistons if... or how much the problem did damage to them... the skirts. You could prep another block and put your parts in it (with new rings) If you can find another block std bore cheap. ($1-200?) I friend or somthing? I know now a days a deal like that is not easy.
Cleaning that block up will probably take more then you should run the pistons in, (.005+ wall clearance) it will run, but getto and hack.
If it dose clean up at 3.907 you should get new pistons for that size ($600) and you would have to have it rebalanced for that. Never used any 3.910, you can for some low power stuff I know stock class guys that do that. The piston cost more too, then a shelf 3.905/3.907 commons. Just somthing to look into, if the machine shop is at fault or anything, or they will prep another block cheap, that needs less machine work. It might come out better for you, god luck,
and if they are then machine the new block to 3.905 and get new rings..
02-25-2013, 01:57 AM
#16
On The Tree
iTrader: (3)
Join Date: May 2010
Location: Ga
Posts: 149
Likes: 0
Received 0 Likes
on
0 Posts
Best guess is you're going to spend as much money boring the block as it would to find a good used standard bore LS1. Taking a block out .120"+ is not going to be cheap (in my area it's anywhere between $450-600). Assembly varies also but I would figure another $300-400 there. Do you know what your PTW clearance was currently...I would try and hone if possible as long as too much clearance isn't an issue. Otherwise you're looking at new pistons or another block if you want to use our old ones. Definitely get quotes and figure out what is best going to fit your budget.
02-25-2013, 02:13 AM
#17
well Im gonna find out tommorow how bad my scratch really is and Ill post some pics on here so you guys can see...
Ive searched and typical ptw clearance for this type of piston is .004 so If I get an hone and reassemble will be 600-700$$ it would be cheaper to buy an iron block 5.3 and punch it out and run my rotating assembly in that... Ill get quotes tommorow..
Ive sent a few pm's to some engine builders on here and the consensus is to run the engine as is, which I might just do... If it last it last, once i get it on the road i can run a compression check and see if those scratches really hurt anything...
If this engine goes I might just look in upgrading my turbo and go larger cubes..
Ive searched and typical ptw clearance for this type of piston is .004 so If I get an hone and reassemble will be 600-700$$ it would be cheaper to buy an iron block 5.3 and punch it out and run my rotating assembly in that... Ill get quotes tommorow..
Ive sent a few pm's to some engine builders on here and the consensus is to run the engine as is, which I might just do... If it last it last, once i get it on the road i can run a compression check and see if those scratches really hurt anything...
If this engine goes I might just look in upgrading my turbo and go larger cubes..
02-25-2013, 07:45 AM
#18
FormerVendor
Join Date: Nov 2012
Location: Sacramento, CA
Posts: 185
Likes: 0
Received 0 Likes
on
0 Posts
Its to bad you're in Southern CA. Otherwise I would be more then willing to stop by and take a look.
I will say, please do not even consider a ball hone. Inconsistencies in the bore from a bore hone will create oil consumption issues. A ball hone, for quality work, is never recommended. I will say, you will be surprised how easy the bore cleans up with a simple dust hone (.001-.002) on a good hone. You may be able to salvage your short block.
Obviously I'm rooting for you in that aspect, but in my opinion, don't take any risks. If you are not happy with the results of that process, you should consider going with larger pistons at 3.910".
Thanks,
Kyle
I will say, please do not even consider a ball hone. Inconsistencies in the bore from a bore hone will create oil consumption issues. A ball hone, for quality work, is never recommended. I will say, you will be surprised how easy the bore cleans up with a simple dust hone (.001-.002) on a good hone. You may be able to salvage your short block.
Obviously I'm rooting for you in that aspect, but in my opinion, don't take any risks. If you are not happy with the results of that process, you should consider going with larger pistons at 3.910".
Thanks,
Kyle
02-25-2013, 11:37 AM
#19
This is an easy way to save steps, should oil pressure not be evident/adequate, or compression out of bounds.
Last edited by gMAG; 02-25-2013 at 11:44 AM.
02-25-2013, 05:41 PM
#20
Its to bad you're in Southern CA. Otherwise I would be more then willing to stop by and take a look.
I will say, please do not even consider a ball hone. Inconsistencies in the bore from a bore hone will create oil consumption issues. A ball hone, for quality work, is never recommended. I will say, you will be surprised how easy the bore cleans up with a simple dust hone (.001-.002) on a good hone. You may be able to salvage your short block.
Obviously I'm rooting for you in that aspect, but in my opinion, don't take any risks. If you are not happy with the results of that process, you should consider going with larger pistons at 3.910".
Thanks,
Kyle
I will say, please do not even consider a ball hone. Inconsistencies in the bore from a bore hone will create oil consumption issues. A ball hone, for quality work, is never recommended. I will say, you will be surprised how easy the bore cleans up with a simple dust hone (.001-.002) on a good hone. You may be able to salvage your short block.
Obviously I'm rooting for you in that aspect, but in my opinion, don't take any risks. If you are not happy with the results of that process, you should consider going with larger pistons at 3.910".
Thanks,
Kyle
So something went down that I don't know about and since I bought it 2 years ago I can't really hit the seller up about it..
they are going to check Piston to wall clearance and see where its at, and then if I can save the block I will. If not Ill take them a iron lm7 5.3 block and have them bore it out to 5.7 and Ill put my rotating assembly into that...
ehhh Ill never buy a used shortblock again, Ill fork over for new that way I know "exactly" the history on it.