I am going to upgrade my head studs to the L19's and change the head gasket to an HKS. I am going to have it tuned to as much as she will put out. I hoping to get this done in December/January at Forged. I am currently at 526whp and 526ft/tq on a dyno jet @ 16psi. I am hoping for over 600whp @ 23psi. I have everything except sleeves and valve train on my block.

 

If you can make 600whp reliably with stock sleeves and L19's, that would be great news for alot of us guys waiting to go built.

 

How much the stock block can handle depends a ton on cylinder temp. I am not extremely in depth on the VQ motor but I am just going to go out on a limb and say they use a iron sleve inside a aluminum bore? If so just like on other cars with this configuration you will have to be very mindful of the cylinder temps. You can get away with making alot of power over short periods but if you keep on it the heat will cause a aluminum/iron expansion rate mismatch and your bores will fail.

Like this!


How thick is the aluminum of your bore?

 

I am sure there are waaaay more factors that go into the sleeves cracking like that.