Engine Temp's

[Norsky4360]

A lower temp range thermostat is not going to help any when the temps rise above its opening point. All a lower temp range does it open it sooner. It has no effect on higher engine temperatures. Also I've been told by master tech level friends that too low an opening point isn't good for the engine either.

I need to check this out on "The Beast" to see if it is true or not, but if the engine temp is running high turn the A/C on. I know this may sound like a strange thing to do but on other vehicles I've owned turning on the A/C automatically turned on the radiator fans.

Another thing to try is to turn the heater on full blast. This sounds like an even dumber thing to do (especially when it is already HOT outside) but the heater core is nothing more than a small radiator. I've done this many times on my '70 and it does help bring the engine temp down some. Because the temp does drop when I do this means I have to take the radiator out and get it overhauled or replaced 'cause it's not doing the job it is supposed to be doing.

[Chris H]

can someone enlighten an amateur on the process of removing the radiator. I am having the same problem. I have also considered wiring the fans to be on all the time (the car is in FL so it not like winter would hurt it) any thoughts on this and an instruction list for cleaning the radiator would be much appreciated

[Aurora40]

I just recently pulled the shroud off to clean it a bit. It wasn't as dirty as I'd thought.

Anyway, the FSM has a good write-up. There are bolts along the sides at the bottom edge of the upper shroud. And you remove the top fan bolts. And then down in front of the car, you have to remove these small bolts that connect the front edge of the shroud to some part of the air dam thing. They are a pain. I had to pull the AIR pump inlet off, and move the AIR pump housing way back to do that. There is also one wire connector to unhook while doing this, for the outside air temp sensor. Lastly the radiator vent hose comes off.

Then the shroud just comes off, more or less. You have to finesse the passenger side off, as the a/c and oil cooler lines are in the way. But that's basically it. It's time consuming, but not that hard.

If you were to remove the radiator from there, it would just be a matter of undoing the inlet and outlet hoses, and pulling it out, I believe.

[flyin ryan]

Originally Posted by Norsky4360

A lower temp range thermostat is not going to help any when the temps rise above its opening point. All a lower temp range does it open it sooner. It has no effect on higher engine temperatures. Also I've been told by master tech level friends that too low an opening point isn't good for the engine either.

'Exactly'!

[flyin ryan]

Originally Posted by 8upZR1

I would recommend cleaning the radiator first. If you have to spend money, buy the chip first. You may be very surprised at how effective the stock cooling system can be with a clean radiator and a good chip. My ZR1 would always overheat when I got it. I cleaned the radiator and the car would run just under the hot mark with a GM chip. With a haibec chip the temp never even reaches the middle of the gauge. I was most impressed.

One thing that did not seem to make any difference on my car was a lowewr temp thermostat. I think I have a 190 or 180 in it now and I never noticed a difference from the stock piece. Goodluck with the cooling.

Here's an indication of what to expect. It actually looks worse in person than the picture's show for some reason. 90 ZR-1 with only 18,000 miles.

[Ccmano]

When your done cleaning it, hold a shop lamp behind it and make sure you can see light through it. (or hold it up to the sun) Fine sand tends to get caught in the fins and is difficult to remove. Unless that's removed your work will be for nought. Also carefully check the support fins around the upper and lower tank outlets for cracks. Overheating will crack these areas first. If any cracking is found replace the radiator. If you just do normal driving and occasional trips to the track a stock radiator is plenty. Don't forget to replace the hoses and thermostat while it's all apart, it will never get any easier.
H

[QB93Z]

Last week I removed the stock radiator from my 1993 ZR-1 with 97,000 miles. It looked like Ryan's picture. I replaced the radiator with a Ron Davis unit. I replaced just the radiator. I kept the same thermostat and the same Haibeck chip.

Since I have owned the car, I have had problems with temperatures running high and it always worried me that if I got stuck in stop-and-go traffic I would have a problem. Also, I could not enter parades because the car might over heat.

Yesterday I gave my new radiator a test. I drove around Washington, DC for an hour in 93 degree heat. (Not FL or AZ weather yet, but up there for MD in April).

In an hour of city traffic, the engine temp was rock steady at 201 degrees. I was VERY pleased. I can enjoy my Z without worrying.

Jim

[ZR1North]

I replaced the radiator with a Ron Davis unit.

Jim
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Jim,

Just curious as to whether or not you had to do any mods to get the Davis unit in. Did it "drop in", or did you have to do some nick/tuck?

Thanks,

Bob

[QB93Z]

Bob,

The Ron Davis radiator tube and fin portion is thicker than the stock radiator. In order to install it you need to make 5/8 inch additional clearance to the fan housing. This can be done two ways:

1. Trim the fan housing. OR 2. Add a 5/8 inch spacer bar to set the fan housing away from the radiator.

I installed a DeWitts radiator using option 2 and the Ron Davis radiator using option 1. (Two different cars.) Here is a picture of the Dewitts using option 2.



I prefer option 1. Trimming the fan shroud took about 15 minutes and is impossible to detect once the fan shroud is installed in the car.

By the way, there is difference between the DeWitts and the Ron Davis units. The DeWitts unit is thicker that the stock unit at the top edge where the rubber mounting blocks support it, requiring the rubber blocks to be trimmed. The Ron Davis radiator fits properly in the support blocks without trimming.

Good luck,

Jim