[Mk2] [Turbo] ARGHHHH Blocks cracked AGAIN!! Dont know what to do.....

[Dangerous]

Really getting p1ssed now spent too much money on my car and got nowhere...

The blocks sleaved and its still cracked!! Im running out of patience (and I ran out of money ages ago)

What do i do know ??

Do I try and find a "thick walled Rev4 block" (Although it could crack aswell)

Or try a 5s block (requires allot of rework)

I dont know how i could afford it?

or Give up and waste 25k and 7 years of pain....

[bolton]

Wat power u running? You using a rev2 block?

[jimGTS]

I believe it's the rev5 blocks that are ment to be thikcer around the water pump area.
Rev1-4 blocks are pretty identical in this regard.

Tho getting hold of a rev5 block won't be easy.


Sorry to hear about your woes.

[djpkins]

maybe you could try an old rev 2 block that has had 16 years of hot and cold and is "tempered" by time and usage more than a newer one...cheaper as well...what are you doing to push the block to destruction? if you are using larger than standard sized pistons then maybe you should sack them and go back to a stock size?

[^Trickster^]

Who is tuning your engine?

Go 5sfe 98+ block, much better and worth the extra money and hassle

Graeme

[JJ]

Stock block and turn the boost down..... You're unlucky there.... I have problems holding the head down !!

I'm getting old an miserable with age... and can't really be ar5ed with complete reworks....

[bobhatton]

Really getting p1ssed now spent too much money on my car and got nowhere...

The blocks sleaved and its still cracked!! Im running out of patience (and I ran out of money ages ago)

What do i do know ??

Do I try and find a "thick walled Rev4 block" (Although it could crack aswell)

Or try a 5s block (requires allot of rework)

I dont know how i could afford it?

or Give up and waste 25k and 7 years of pain....

Need a lot more info to understand why it is cracking. What is in the engine and what intercooling do you have and what boost do you run?

Bob

[JJ]

Need a lot more info to understand why it is cracking.

I've mentioned on occasions where I've see the block crack externally that it can be related to the ARP studs being tightened too much instead of it almost loosely fitted .. ie. tightened, then qrt/half turn backwards.

The ARP's can be subjected to a little expansion with heat and if tighten firmly against the cast block, it can potentially crack it.

2ps worth !

[Dale_V]

my 2p is that the cracking cant be pinpointed to any specific reason. I cracked the block on my totally standard rev2 3SGE/NA block ...

[JJ]

my 2p is that the cracking cant be pinpointed to any specific reason. I cracked the block on my totally standard rev2 3SGE/NA block ...

Was this with nitrous or without ???!! Think nitrous would play a fair factor in this due to the massive reduction in air temps .....

[Dale_V]

my 2p is that the cracking cant be pinpointed to any specific reason. I cracked the block on my totally standard rev2 3SGE/NA block ...

Was this with nitrous or without ???!! Think nitrous would play a fair factor in this due to the massive reduction in air temps .....

yup, no nos, NO mods, just back in the day when I ran a totally standard NA, not even an aftermarket air filter

[JJ]

A cold snap without a good concentration of antifreeze can do that !!

We need to think outside the box sometimes... !

[bobhatton]

The ones I have seen crack have been REV3 with a 3" crack at about 45deg in cylinder 2. Both caused by the engine over heating and losing water.

Bob

[JJ]

Both caused by the engine over heating and losing water.

Do you mean this from a tuning angle where the cylinders are getting too hot ( running lean ) thus boiling the surrounding coolant in the block or do we think theres an issue with flow through the block / thermostat....

I've noticed the cheaper thermostats compared to the toyota ones have a smaller diameter valve of flow through them.. which doesn't help:-k

[Dale_V]

A cold snap without a good concentration of antifreeze can do that !!

We need to think outside the box sometimes... !

it was june 2006 (the warm summer) with pretty much new toyota forlife.... what else is outside the box lol???

[bobhatton]

The REV 3 oil cooler pipe work is much larger and flows to a different place on the block than a REV 1&2 so I am not sure if this takes water flow away from the block. I need to look deeper into this and maybe remove the oil cooler from the block and just use an air one.
I do think the problem is one of water flow through the head and block. Going to do some tests when I get the time.

Bob

[JJ]

The REV 3 oil cooler pipe work is much larger and flows to a different place on the block than a REV 1&2 so I am not sure if this takes water flow away from the block

Looking at it, I'd say the feed travels from the block ( exist ), through the cooler.. then onto all the ancillaries ( turbo feed / heater matrix ).

Now what the water pump does to the other pipes looks a strange old affair and looks to pull the superheated coolant from the turbo back to the pump ( with the coolant channel from the swirl pot too )to circulate in the block again before it all exists at the swirl pot / sensor array > to the rad... When the block gets upto temp, the lower part of the thermostat shuts off this channel and thus only diverting the heated coolant to the swirl pot. .. I'm not 100% on that.. but will confirm in few weeks when I get dirty again...

maybe remove the oil cooler from the block and just use an air one

I have both in series... brings the oil temp upto working temps in the BBBRRrr cold winter months...

[Dangerous]

Stock block and turn the boost down..... You're unlucky there.... I have problems holding the head down !!

I'm getting old an miserable with age... and can't really be ar5ed with complete reworks....

Tell me about it !!
I ran it in for a 1000 miles changed the radiator because it started leaking...
got it remapped it made a poxy 350rwhp on raceshacks dyno at 2bar on TO4Z then it cracked the manifold after half hour (which was thought to be a restriction)the same day!!

then i spent another 1k on a a pheonix power manifold having it fixed/reworked and fitted, went back down to the dyno on the way coolant came out the expansion tank.....hmmmm

We (me and my engine builder) put it on the dyno for another remap (keeping an eye on the expansion tank) no water....no difference in power..hmmmm so we swung the cam timing and it made an extra 20 rwhp...rubbish..

THEN...

on my way home my wastgate decided to give up (stick open)

Then 2 weeks later it over heats (thought to be an air lock from the new rad) takes it back has the coolant bled...

Then takes it for M.o.t ....over heats while being tested...so now were at this point after the engines been stripped down and.....
Its twisted the block which has caused the block to crack between cyl2&3 at the bottom and the sleeves have dropped making the head gasket fail....Arghhhhh!!!!!

I think its time to break me car as i cant afford the 2k rebuild price....

[Dangerous]

Really getting p1ssed now spent too much money on my car and got nowhere...

The blocks sleaved and its still cracked!! Im running out of patience (and I ran out of money ages ago)

What do i do know ??

Do I try and find a "thick walled Rev4 block" (Although it could crack aswell)

Or try a 5s block (requires allot of rework)

I dont know how i could afford it?

or Give up and waste 25k and 7 years of pain....

Need a lot more info to understand why it is cracking. What is in the engine and what intercooling do you have and what boost do you run?
Bob

forged everything really a full 7k build (i dont wish to disclose the builders company) it was specced to run 600hp pistons/rods/crank/ modded oil flow bearings sleaved block etc etc all fed through a t04z (2bar max)(however it was hardly used) 1.6 bar for road use...it has a boot mount pwr chargecooler (peak temp 40'c at 2bar boost) it was ran in for 1000miles and has had 1500miles of road use

[JJ]

hmmm....

What size pistons did you have in it ???!! Again, I'd go for a stock block, find a knackered crank one or blown piston... refit it all back together with your parts... and keep the boost down...

Can't beleive you only got that little power out of it with the T04Z ??!! Mine was producing that at 1.4 bar.... same turbo...

Any consellation ( obviously pending your decision )... I found the turbo a lot more usable with a 0.61 a/r turbine...