needadvice

My friend has a 4.100 bore on his relseeved LS6 block and its got about 30,000 miles on it after his second re-hone and re-ring a couple years ago. He's burning alot of oil and he wants to bore it to 4.130 and get new pistons to definitely start fresh with nice round cylinders.

Can that be done without loosening the sleeves or causing any other problems?

jermzz

iTrader: (18)

You can bore it with no problem, the sleeve thickness is what comes into play.

What's the diameter of the sleeve? (4.4 - sleeve diameter) / 2 will give you the sleeve thickness per cyl.

are they mid sleeves? If so, Darton recommends at the very minimum a .075 sleeve thickness.

needadvice

Whatever sleeves that were available in 2002 for the LS6 is what they are.

How can he know if 4.130 bore is safe size to go to for an N/A engine? Or even go to a 4.125 bore, whatever it takes to start fresh with nice rounded cylinders.

Steve - Race Eng

iTrader: (1)

He doesn't have 4.100" bore MID sleeves because we never made any that size. He must have some sort of dry sleeved block. I would not recommend going any larger with it. The max. OD on the dry liner is limited by the coolant passage between the bores. This limits the wall thickness of the sleeve. Most of the dry liners had a max. OD of 4.250". At 4.125" bore that leaves only .060" wall thickness which is not enough for a dry liner in a thin wall aluminum block even if the material was the same strength as Darton's.

Steve

needadvice

You know what, he does have dry sleeves, he told me tonight. I guess he's screwed than because he already honed them twice and he thinks his cylinders are out of round. Guess he needs a new block with new sleeves.

jermzz

iTrader: (18)

Listen to Steve, he knows

MID sleeves came out in 2002, but obviously they did not gome in a 4.100.

Based on what Steve said, you're already at max bore.

Steve, is smaller then a .075 wall applicable in an N/A motor?

VintageCamaroChris

iTrader: (3)

why not take it to a machine shop and see what they say? Maybe you can bore it .010 or ,020.. I bet it would be OK, thats not much material. I would do some measurements and checking before you just buy a new block...

Steve - Race Eng

iTrader: (1)

What you can get away with on a dry sleeve for minimum wall thickness depends on the strength (thickness) of the aluminum supporting it. The LS2 LS7 blocks are stronger and thus we can take the wall down to .070" wall at 4.185" bore without problems. Chuck Nuytten told me they have run the Darton dry liner as thin as .057" on some of their large bore nitrous billet big blocks with no problems.

The problem with dry sleeving the LS1 LS6 blocks is that water passage between the cylinders. I wouldn't try to run the sleeve down to .070" with nothing behind to support it. There is no way it will stay round in service. I would keep the wall at .093" to play it safe.

Beast96Z

iTrader: (21)

Sounds like a old Agostino dry sleeved LS6 block. If you listen to what Steve says, then you'll come out peachy.