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!!!

[Alan]

Seriously Know one has any info about this??? I thought 6GC would know but looks like know one does :s

[njccmd2002]

sorry bro, not like the old times here, you may get more info on this on the mr2oc forums, since some of them have similar applications.

few conversions here, few engine builds, nothing out of the ordinary. unless you want to find out if and old Camry key works in you car. lol

aint the 3sgte block similar to the 3sge? seriously join mr2oc, that's the only place where i have seen serious builds... i wish i could be of help.

[Rusty]

There was some info on road & track au website, but I cant find it anymore

other sites which may help

http://gtfour.supras.org.nz/

http://www.gtfours.co.uk/

[Alan]

Yeah I tried all these site Know one seems to know What is best to do it suck and is very disappointing I dont know what to do with my block if I should just scrap it or just buy the 5s block and new forged pistons which is a shame cause I already have je 86.5mm pistons but I cant use them with the 5s block.

So this site isnt good anymore for race builds just the normal swaps I guess :S

I mean it sucks I have to go on an mr2 forum while I have a celica 6th gen what happened to this forum ?

[lagos]

For a build like this, most people go with a 98+ 5sfe block.

[Rusty]

The road & track technical article I thought was quite good, but they basically said if you order a new block from Toyota there's no guarantee that you'll get the stronger block.

The NZ GT-Four owners (the ones who have done some interesting engine builds) don't really post on global forums. Also you have places like CCuk GT4DC & GT4OC, & 6GC altough is world wide, there are lots of USA members on it and they didn't get the GT4 like we did.

[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.

[mgnt232]

Our heads are the real first limiting factor (for an extreme hp goal). And as Art (lagos) mentioned a 98+ 5s block is the best for this swap.
If you are not a member of mr2oc for this power goal… you're wrong.
Also with 850whp…. you need to go AWD. I spin a ridiculous amount at a little over 300 lol, you will just sit there and spin wheels at 120mph if you aren't.
I have a pretty good thread on mr2oc (link here) that has a TON of info for going up to about 600 (which is already ridiculous) read through that.
Info on 5sgte builds, e85 conversions, ect.

This post has been edited by mgnt232: Apr 5, 2014 - 7:30 PM

[Special_Edy]

Fill the bottom 2/3rds of the water jackets in the block with either concrete or the stuff they make specifically for this purpose. It will stiffen the block and improve the performance of the cooling system at the same time.

[Bitter]

From memory it's because of thermal stresses caused by boiling between cylinders 2 and 3 due to the very very narrow coolant passage. Higher cooling system pressures, non boiling coolants, etc can help, as can meth injection.

[Special_Edy]

From memory it's because of thermal stresses caused by boiling between cylinders 2 and 3 due to the very very narrow coolant passage. Higher cooling system pressures, non boiling coolants, etc can help, as can meth injection.

Then using a block filler would be even more effective. By filling the bottom of the water jackets you are removing a significant amount of volume from the coolant system. The vast majority of the heat is going to occur at the cylinder head and the top of the cylinders where the combustion occurs, not the lower 2/3rds of the cylinder. By filling in the water jackets you are increasing flow of coolant through the block, thus running a cooler engine.

[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