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!!!

[Bitter]

but you're also reducing cooling system capacity and I'm fairly sure that Toyota engineers don't just put in coolant passages willy nilly for fun, I'm sure there's a good reason there's cooling going on down there. You'd need something that would expand/contract at the same or a similar rate as the cast iron and would be compatible with the coolant.

http://speedtalk.com/forum/viewtopic.php?f=1&t=647

There's a good thread about it, lists some good products and explains the need to give aux cooling to the engine oil since filling the block partially removes a lot of the cooling provided for the oil It also touches lightly on a big problem he'll run into...the knock sensor! Filling the block will really alter the resonance rendering the knock sensor useless. Knock will happen but it will be at the wrong frequency or dampened greatly and the knock sensor won't hear it. You'd need to induce knock on a dyno, verify with EGT/Wideband feedback and use a wide band knock sensor to find the new frequency then match it to an off the shelf sensor that can 'hear it' then figure out how to make it work with your engine management, assuming there's some kind of capability built into it for something like that or build a standalone knock sensor that could output like the stock to the ECM. It could get really complex.

This post has been edited by Bitter: Apr 7, 2014 - 11:45 PM