3rd gen 3S block, The "Cracking issue" Options

[Alan]

Hey guys I am currently building a 3rd gen 3s engine and my only concern is the block cracking problem my Block is a 3s 1996 block it is the thicker reinforced block.
I am aiming for big HP (850WHP), but this block roumors are getting abit to old everyone says different thing about it use sleeves dont use sleeves use Hardblok dont use it, leave the bore standard... alot of mislead info

Can anyone out there share with me what I should be doing with my block should I sleeve it or not the bore I am going for is 86.5mm I have had someone tell me its not safe to go above 650 with this bore this person uses sleeves and has no probs but I have other freinds stating that the sleeve will still crack so basically I dont know who to belive .

I have spent thousands on parts I dont want it all to go to ****s after all this money spent only weak spot i found is this block issue so please anyone out there running big hp on a 3S share with me what I need to do.

Also I would like to use the 3s block I dont wanna use the 5s!!!

[jbod]

Haha rusty yea im surprised no one knows a huge amount - we are forever having this discussion! Okay well i wouldnt bore out a gen 3 block, i can think of a few that have cracked because of doing this. However to be fair one of my friends bored his gen3 out, resin filled about 2l of the lower block, revs out to 9k. And has been tracked / daylied for the last 60ks. 320psi comp on cylinders under boost. Id say its almost a lucky dip, he hasn't had issues... Tho i know a handful of people who have had issues with cracking after boring them so i just wouldn't do it, too risky..

If your going to go wild with the forged thing use a generation 4 block. These are great. Out of the caldina gtt. These support good power with no funny cracking characteristics.