Secret project-1KZ-TE cracked head wanted

[GreyGhost]

I'm having a look at the cracking head problem on the Toyota 1KZ-TE.
The bottom mounted thermostat doesn't help at all.
I need a 'spare' head to play with to make up and fit an adaptor.
If you are in the Nelson area and have a buggered head that I could 'borrow' for a couple of months then I would be most grateful.
You will get your head back so you can get the scrap value for it.
I just need to use it for a while to make up and fit my adaptor to get the measurements and layout right.
Even a smashed head ('cos you got mad at it?) is fine as long as the front water outlet part is still there.
If it works how I plan it then I'll start making a few.
Thanks for any help.

[kbushnz]

Hi yah Bud
have a read of this forum re top thermostat housing.
http://toyotasurf.asn.au/forum/viewtopi ... 9&start=50
You can buy inline ones which can go in the top hose.
Its something I have been thinking about for my 1KZ...
http://www.ebay.com/bhp/inline-thermostat

There is also talk about the pros and cons of blocking the bypass curcuit...

[GreyGhost]

Yes, I knew about the inline ones.
I'm thinking a more 'traditional' top housing.
Thanks.

[tweake]

the reason they have a bottom thermostat is to stop head gasket failure due to having the alloy head. fitting a top thermostat will cause head problems.
you will also need to somehow reroute the thermostat bypass.

the problem really isn't the thermostat. the thermostat is there to keep the engine warm.
most of the issues is the lack of cooling. thats the radiator, oil cooling and internal cooling.

i would put the work into oil cooling, have a closer look at the thermostat bypass, look at running dual bottom thermostats (ie a smaller one to open earlier to give a more gradual thermostat opening).
better intercooling.

[Crash bandicoot]

the reason they have a bottom thermostat is to stop head gasket failure due to having the alloy head. fitting a top thermostat will cause head problems.
you will also need to somehow reroute the thermostat bypass.

the problem really isn't the thermostat. the thermostat is there to keep the engine warm.
most of the issues is the lack of cooling. thats the radiator, oil cooling and internal cooling.

i would put the work into oil cooling, have a closer look at the thermostat bypass, look at running dual bottom thermostats (ie a smaller one to open earlier to give a more gradual thermostat opening).
better intercooling.

If its cracking heads due to the location of he thermostat and lowerd it then its not the thermostat that is the issue, its th inherent flaw in the head design. Td`s have stat at th top, rb rd have stat half way down the block doesnt worry them one bit.

[tweake]

the reason they have a bottom thermostat is to stop head gasket failure due to having the alloy head. fitting a top thermostat will cause head problems.
you will also need to somehow reroute the thermostat bypass.

the problem really isn't the thermostat. the thermostat is there to keep the engine warm.
most of the issues is the lack of cooling. thats the radiator, oil cooling and internal cooling.

i would put the work into oil cooling, have a closer look at the thermostat bypass, look at running dual bottom thermostats (ie a smaller one to open earlier to give a more gradual thermostat opening).
better intercooling.

If its cracking heads due to the location of he thermostat and lowerd it then its not the thermostat that is the issue, its th inherent flaw in the head design. Td`s have stat at th top, rb rd have stat half way down the block doesnt worry them one bit.

thats not quite what i meant.

the reason manufactures put the thermostat at the bottom/mid is to reduce sudden coolant temp change due to the sudden opening of the thermostat.
i suspect the inrush of cold water cools the iron block/liner at a different rate to the alloy head. this causes the head gasket to fail.
if you go from bottom/mid thermostat to top thermostat you will make another head issue.

your TD is all iron block and head so it doesn't matter, much like my 3L. with my temp gauge i can see the sudden change in temps when the thermostat opens.

have seen pics of setups where they have put small primary thermostats which open before the main one. that allows coolant to circulate and push through the cold water out of the radiator. this helps even out the temp changes.

the 1kz spec i have here is that the 1kz thermostat fully opens around 90 odd (10mm lift at 95c). so the "cold" water is 90+ before it cools the head . not much head room. compared to the older 3L engine where its 90 odd coming out hot from the engine then being cooled.