Radiator Workings - Cooling issues 1uz->Ra23

[stradlater]

Hey guys,

I know I've covered this a bit before, but I find that my car has significant difficulty cooling itself properly.

I've noticed that I have the radiator pipes around the wrong way, atleast different from stock which is the return to the top and the feed to the bottom. (the way I have it, stock appears reversed).

I'm curious to know if that makes a great deal of difference? Every image that I've seen on the net suggests that the way I have it hooked up is right, however stock is different?

Also, I have two thermo fans, one 12 inch, one 10, I'm thinking that a single 16 might be more useful, which I'll investigate.

Thoughts?

The radiator itself is a freshly triple cored standard RA23 copper radiator, so it's the same size (LxW) as a standard ra23 radiator, but triple cored.

[LeeRoy]

You want the pump to be fed from the bottom so gravity helps get the water in there, so i'll suggest you reverse the way it is currently plumbed.

Might also help to seal up the sides of the radiator so no air can bypass it and so it's forced into it.

[stradlater]

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.

I think I'm going to upgrade my thermo fan to one big 16" one, with a cowl....

[the_random_hero]

You need a shroud installed for a thermo fan to work effectively. Will two 12" fans fit side by side? Make sure they are either pushing/pulling the correct way (depending on where they are located).

[MWP]

Thermo fans should only be required when idleing, stuck in traffic, or pushing the engine hard for long periods.
Driving steady at 60kph on a warm day shouldnt need a thermo fan at all. The air flow through the rad should be enough by itself.
If this isnt the case, then the rad is too small, you have air flow issues or some kind of coolant flow issue.
I would be fixing those things first before just bolting on a larger thermofan.

[foamy]

Gravity helps to some extent, although the radiator should still be effective pumping the water against it.

Example in case is the Holden Frontera. Radiator has both hose pipes in the top tank, meaning the water must be pumped down then back up again....

[stradlater]

The_Random_Hero - I might try the shroud, though given air flow issues already, I'm hesitant.

MWP - I think you have a few good points. A) the radiator may be a little too small, htough I dont' really have much other choice given the space. B) at 60kph it has no issues with heat, the thermo's don't come on at all when driving, unless it's been pushed a bit, or stationary. Really the biggest issue is after a bit of a push, then stationary, the heat goes up REAL fast. I would doubt a coolant flow issue, it all looks pretty clean. But I do have significant airflow issues, there's 4 inch thick cooler right in front of the radiator, so that limits things a bit. I have a 12" thermo on the front on one side and a ten inch thermo on the back on the other side. I might upgrade the 10 to a 12 but not really expecting a great deal from that. There might be current flow issues to the thermos too.

Foamy - Thanks for the heads up on that one, I'm now convinced my piping isnt' the issue.

[RiceburnaGTV]

So you have fans on front and back of the rad? I would drop the one on the headlight side and put it on the rear with a shroud. Im honestly surprised its cooling when moving at all with the restrictions there, but that isnt your problem. Keep the cooler and rad positioned where they are as in the current gap between to 2 and get a good slim line fan behind that rad on the engine bay side.Try and keep a gap between the cooler and rad so the fan isnt having to pull through the core of the rad AND the core of the cooler to get any fresh air when stationary. If you shroud the fan space it 10mm back from the core minimum. Sometimes with extra long pipe work you can suffer from cavitation but I dont think that would be happening with this little set up..And one last thing, you havent taken out the thermostat? Thats a common mistake..See how that goes mate..

cheers
Nath

[stradlater]

No space on the back side of the radiator, that's the problem!

[RiceburnaGTV]

No space on the back side of the radiator, that's the problem!

Shit sorry mate I read it that you had a 12 on the front and a 10 on the back. Slim line push on the front it will have to be then.

[Kedderz]

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.

[thr55t]

Royal purple 'radiator ice' or Motul 'mocool' are good to wipe a couple of degrees off.

[stradlater]

Ah,, so there's coolant that might help as well? That sounds good!

Not sure that I can fit the 16 inch thermo now, I've had a look and the harmonic balancer is a bit close.

I also can't se ehow I can get a bigger radiator in, I just don't see where it would fit!

[Kedderz]

If you cant fit the 16inch, put a shroud over the 12 and the 10 inch fan just make sure its spaced at least 10mm away from the radiator so it can draw air effectively through the radiator.
I fit the 50mm alloy rad and a 76mm intercooler in mine and I still have the proper grill mounts, how far forward does the 1uz sit in the bay to not allow a decent radiator?

[SHEPPO3930]

in addition to the shroud, you need to make sure the hot air exiting the radiator has somewhere to go. either lift up the rear of the bonnet (in conjuction with removing the rear bonnet seal), opening up the stock vents at the back of the bonnet, and/or fitting vents behind the radiator.

do you have the factory under-tray fitted (the shroud that goes from under the radiator crossmember back to the engine crossmember)? I know without this some cars run hotter.