jdbaugh1

iTrader: (1)

I have a 2006 L61 TVS Cobalt with forged rods and pistons. The engine has good power but is drinking oil. Like almost a quart to a half tank of gas. I have a leak down tester but haven't used it yet. Should I be able to confirm that it is the rings with that? Only other possibility, that I know of, would be the valve guides but as that is an much easier fix I assume that is not the problem. If it is the ring to cylinder wall seal that is bad I plan on getting a used or new block and was hoping y'all could help me get pointed in the right direction.

As far as blocks go I can get high mileage used LSJ block from mongorat. But I think the only way to properly do that is to go with overbore pistons so I have a fresh cylinder fit. Is it OK to overbore an LSJ block .020# or will I be asking for trouble? My build is only running on a 2.9" pulley so I don't plan on making crazy power. I also don't want to waste a bunch of time and money getting this put together just to have it give me problems.

As of right now I was planning on getting a used LSJ block and have a machine shop correct the bore for me and install .020" oversize pistons. I think I will be able to re-use the crank, con-rods, and head. I'll just need new pistons, bearings, and gaskets if I am thinking correctly.

Once again I am open to ideas here. I want to do it right ONCE.

Sharkey

iTrader: (1)

typically you dont bore ecotec blocks, if a sleeve is worn to the point of needing to be bored and have oversized pistons put in your supposed to change the sleeve.

ItalianJoe1

iTrader: (10)

Yeah just install new sleeves and have them bored to stock size, don't go overbore. Too thin.

jdbaugh1

iTrader: (1)

Are there any issues that arise with installing new sleeves or is it a pretty common procedure?

Looks like replacement sleeves would cost be about the same as new pistons so if I get sleeves I should be able to reuse my pistons. Anywhere you guys know of for getting sleeves from? I found some at OTTP that are supposedly stock style but better material. Anyone know of or have experience with these?

If I go the route of new sleeves + old pistons I will need some new rings. Is there a big advantage to total seal rings to justify their cost? Like I said I want to do this right I just don't want to spend extra money somewhere if it isn't really going to benefit much.

Edit: Also do machine shops typically have the capability to install sleeves? I know there is a tool out there but it probably wouldn't be very economical to buy the tool just to install sleeves once.

exninja

iTrader: (1)

It's pretty common so a reputable machine shop should have no problem doing it. You can always just call ahead and ask.

jdbaugh1

iTrader: (1)

Will definitely call ahead to machine shop. Shops around here deal with mostly V8s so I didn't know how common it was to have this capability.

For a new bare block what all components do I need? So far I have identified:
-New stock LSj sleeves
-Main bearings
-Con-rod bearings
-Piston rings
-head, intake, and exhaust gaskets
-Any seals? or anything else?

jdbaugh1

iTrader: (1)

Alright so I am shopping for main girdle bolts and am getting a bit confused. on CED there are Ecotec main girdle bolts and they say that 20 are required. But then they also have LSJ and LNF specific main girdle bolts and they say that requires 10. So is there 30 main girdle bolts altogether? If I am using an LSJ block but with L61 crank and girdle what bolts do I need?

Edit: I found a picture. Looks like there are 20 TTY bolts and 10 outer bolts on the girdle. Why are the LSJ and LNF bolts different? Will I reuse my stock outer bolts or do I need LSJ outer bolts?

jdbaugh1

iTrader: (1)

I am having trouble finding anyone that can swap out sleeves. Do dealers typically have this capability? All the performance machine shops around here pretty much only know their V8s and have never swapped a sleeve. The tool is way to expensive to just use once. Looking for ideas.

exninja

iTrader: (1)

I'm no help but I am surprised the shops don't do it. It's done on V8's as well. They may never have "swapped" a sleeve but someone has to have installed them. Removing the old one isn't hard, just bore it out.

ECaulk

iTrader: (6)

I have a feeling it has to do with the fact it's a 4cylinder, some of those V8 guys are way to dogmatic

jdbaugh1

iTrader: (1)

Do you bore out the old sleeve or press it out? Everything I have seen shows using that Kent more threaded tool for pushing and pulling. Or can you do it either way?

I will be contacting some machine shops a little further away see if they have the competency.

exninja

iTrader: (1)

I honestly just guessed, but pressing out makes sense. At work (aerospace) we usually bore out stuff like that but it's a lot smaller.

ECaulk unfortunately is probably right, a lot of those V8 guys would pass on work rather than work on something they consider "inferior." Makes zero sense to me.

jdbaugh1

iTrader: (1)

To be fair they just mentioned that is what they typically work on and don't really have experience with "imports" lmao. I found another machine shop that had never swapped sleeves but is willing to figure it out. I'm also going to have that same shop basically assembly the short block for me.


I took off some extra days to make this a long holiday weekend and I hope to get the engine dropped in that time frame. LSJ block, sleeves and other parts will be in next week.