Radiator Workings - Cooling issues 1uz->Ra23

[RiceburnaGTV]

I have/had the same probem with my 1g + ra23, 60kph its fine, going for a fang is fine as long as i dont slow down, if I stop after a fang temps shoot right up, exactly the same problems you are having. Only difference is I have a JAR alloy unit AND two SPAL 12inch fans with NO shroud. If i wait long enough eventually the temps will come down abit, for me its purely a airflow issue.

Next setup I have will be a bigger radiator with custom supports/mountings, hopefully a s13 rad and AU thermo setup as that cools very well from what ive seen.

My suggestion is a proper shroud setup for your 16inch thermo when/if you get it. River also had the same issues with his 18rgte, IIRC he had a shroud made and his cooling problem was fixed.

Shit mate I didnt know you were having issues with yours! Let me know if I can do anything to help? Happy to make up a shroud to suit if need be. I might have to start toying with some thinner core cross flow dual pass designs for these engines?

I remember Blake (guilty) got a notch off his crank pulley milled off for some extra fan clearance, is that something you may be able to do too strad?

[Kedderz]

The Radiator isnt the problem, its the airflow at low speed that is, there simply isnt enough air being pulled through without a shroud, the 2x fans I have really only act on maybe 50% of the radiator, so its unfair to blame the radiator and again when you are moving the temps go right down so its doing its job (the rad). I would reccomend that if you can doing a shroud and fan or just shroud option on your radiators.

Im ditching the 1g and going something else which required a complete custom IC/rad setup so im in a different boat again.

[RiceburnaGTV]

Cool mate, yeah shrouds are will be a norm very very soon with all my rads, managed to find a place to import them from and can then stop paying $200 a pop myself when i need them made up!!

[matty12]

Leeroy - The water pump is fed from the bottom. I think it's other people that have been wrong, not me. Because my thermostat goes to the top of the radiator, and the waterpump is fed from the bottom, albeit through a rather sizeable hose.

Have i read this right, you have the hose with the plastic cover and thermostat to the top of your rad??

If so the thermostat is in the bottom hose/inlet to engine(black plastic cover) and should be connected to the bottom of the radiator, the top hose/eng outlet should be connected to the top of the radiator, i think you have it incorrect.

[stradlater]

Matty - That seems converse to what others have said?

Others have said that the water pump is to be gravity fed from the base of the radiator. Therefore, the Thermostat outlet must go to the top of the radiator? This is the way I have it now.

IE -

1UZ, black cover thermostat housing outlet -> Top of radiator

1UZ, All Alloy waterpump feed pipe -> Bottom of Radiator.

You suggest otherwise?

[stradlater]

Here's how it is.

[ian]

hi strad
i measured up mine and with a little trimming of the radiator support panel i can fit a vk v8 crossflow radiator
and the inlet and outlet are in the right position this is a six cyl vk radiator for the excercise

in other 1uz conversions all the hoses that i have seen come from the thermostat to the lowest part of the radiator
lexmaz will be able to confirm this with his 1uz mazda conversion

the top hose may be a bit tricky but i will adapt and overcome

ian

[lexsmaz]

As Ian mentioned the hoses should be on the other way around so your radiator flow at the moment is basically running back to front or bottom to top, easiest & neatest way get the fittings swapped over side to side on the tanks ..

Look's like its quite busy & restrictive under your bonnet ..

Whats the total coolant quantity that your radiator holds now as opposed to a 1UZ radiator, as Ian mentioned mayba bigger radiator is a better option too, also what cap pressure do you have ..

As has been mentioned i would be looking at shrouding of the fans & covers underneath the car & some ceramic coating of all the exhaust pipes etc to keep down the under bonnet temp's, or you could wrap them but i heard a little while ago it tends to crystalise the pipes after a while if they are wrapped ..

Maybe a smaller cooler up front may help with the heat soak issues too, how much boost & power are you making ...

Can you set your thermos to come on quite a bit sooner, it might help a bit as the fans will be working before the temps get to high, as at the moment they have a big job of trying to catch the temp & then pull it down ..

Another thought is if all else fails mount some small radiator / heater cores under the back end of the car or where ever else & plumb up with thermo fans on them too ?

Rob ..

[matty12]

yep, you have the hoses around the wrong way, if you paull the thermostat out you can actually see the impellor of the water pump, this is the water inlet to the engine. Like most latter model jap engine the thermostat is in the bottom hose.

It sounds like you have airflow issue and need to make the most of the space available and fit the biggest pusher fan you can. Any bonnet venting shound be down at the front edge of the bonnet( just behind the rad) as this provides the greatest pressure difference between incoming air- exitting air. The space below the windscreen is a high pressure area.

[Supra967]

Strad I was confused looking at it the first time as well. Definitely around the wrong way, you can tell because the coolant bridge outlet is just a little bit higher than the thermostat inlet, always keeping gravity feed to the pump.

Have you been able to burp it properly? You're filler looks mighty close to the same height as the top bridge, maybe even a little lower when the car angles down at the front?

[stradlater]

Matty - The more I think about it, if the hoses are the wrong way around then it's DAMN obvious that the thing can't cool!!!! So I need to fix that before worrying about too much else.

Supra - I have tried to burp it, it seems all pretty good, because I lift the car up at the front to burp it first, that and fill up via the filler bolt at the top.

TBH I think the prime issue I need to fix is the radiator outlets.

Biggest problem is, the alternator is right where the outlet should be!

[Supra967]

to me it looks like the top hose could easily make it to the bridge with a 90 degree bend past the thermostat. You might be able to find a thermostat housing with the same bolt pattern that points the other way off a different engine? From memory Supercrap sell a range of universal looking thermastat covers.

If so you can leave the rad as it is and do a fairly easy hose swap.

[ian]

hi again strad
if your alternator is in the standard position , you can modify it it to pivot
out of the way ,if you get down my way i can show you what i mean , lexmaz may be able to put up a piccy of what he
has done as well , i have done away with all the other stuff like the idler pulleys etc .
so now there will only be a short belt to the alternator from the crank pulley