Ok I have a stock gsr block that dropped a valve and and cracked the oem sleeve on 2 spots on the cylinder. I've heared that any crack longer then 2 inches that the block is garbage. I then took the block to a machine shop and he said that he couldn't put AEBS sleeves in it cause its cracked to far, but he could put a DARTON sleeves in. So is it ok to put sleeves in just cause he said so? Risky? Why only DARTON and not AEBS or GOLDEN EAGLE etc? It would be a back up block for a boosted application. So is a 2.5" to 3" cracked sleeve really garbage or what?

 

i belive the GE sleeves still retain a portion of the lower aluminum of the oem cyl, if the crack gets past where they meet, you probably wont have a good seal and it would leak water into the oil pan.(that is if you happend to sleeve the cracked block to see what would happen.) i supose it could go as far as reaching the main feed oil galley (large feed)

as for the others, i dont know.

 

There are a few open deck sleeves that use the lower aluminum of the OEM sleeve for aftermarket sleeves. This is used for sleeve alignment, support to prevent sleeve sinking, and strength.

As for how far down.... I'm not 100% sure. I'm almost positive you can get away with a 2.5" crack and no further.

 

Why don't you pm Rob (Golden Eagle) on here and give him a shot first. You can tell him I sent you. He'll help you out if he can.

 

The reason he would say Darton is because the MID sleeve does not use any of the stock sleeve for support. All of the stock casting is removed to the mains. Unless the crack goes down through to the mains then the block is junk.

 

If you need to go with Dartons, make sure you do the right thing and send the block to Darton. We had them remove our MID's from our D16z6, local shop installed them, and install them in a second z6 a few years back.


I just checked the 2 blocks here, one GE sleeves, one AEBS sleeves and the AEBS sleeve s go all the way through the bottom of the cylinder webbing. I can't see what the machine work looks like behind the sleeve though.

I seem to recall our bad block that had the MID's sleeves removed had quit a bit of machining to allow the sleeves to seat and seal. That block is down at our local shop.




Modified by 1992Si at 11:07 AM 6/29/2008