89vette

OK ever sice I put in the 396, she is running a little hot. Its hot in Pittsburgh this week with temps in the lower 90's nd very high humidity. With the AC on in stop and go traffic yesterday it got to 227. Hiway speeds with AC on its about 195 to 210. It ran much cooler with the 350. I run a 180 stat and BOTH fans turn on at 185. I have heard that a water wetter can help. Where do I but that? Anyone have and experiance with it?

Jason

ChrisB

Try a 160 stat and turning on both fans at 170, 190 over highway speed (I use 55).

It sounds like your issue is just one of cooling capacity though - your motor is making more heat than your cooling system can handle.

What mixture are you running - You could try a 80/20 water/anti-freeze mixture - make sure to throw a couple of bottles of water wetter in there also. (anti-corrosion if nothing else)?

If none of that helps it might be time to step up to a better radiator (griffin on becool).

Vic'89

Jason

I have used water wetter with pure distilled water only in my Iroc. It helped a little with lowering the temps, but nothing great.

I think is costs about $10, so you might as well try it. From what I remember, they recommend running water only.

Vic

ChrisB

I have run distilled and water wetter also - the watter wetter helps with the corrosion, but due to it's volume it simply can't do as much as coolant. (buffering capacity, etc.)

If you do this I would recommend getting a block of magnesium and electrically grounding it to the radiator (I used a copper strap) and immersing it in the cap. This magnesium will then oxidize before the rest of your cooling system does - you do have to replace it periodically though.

89vette

I also feel its more of a capacity thing, Chris. I'm running a 50/50 mixture right now. Are the Becools and Griffins direct replacements or are they chop and hack installs? Would I hi volume water pump help any? If I speed up the motor is seems to cool a little.

Jason

Greenvette

I put water wetter in my big block and it helped alot when I lived in the california desert in the middle of the summer where temps were 100-115 deg everyday. My wife drove the car everyday working as a salesperson for the chamber of commerce. It was the only thing that brought the temps down. I also put waterwetter in my 88 along with Redline synthetic oil and I had no problems with heat running with the air on. An aluminum radiator woulde also help considerably. I member in my corvette club has a big block that ran very hot in parades and driving around town. He put an aluminum radiatr in his vette and solved asll his heat problems. Hope this helps. Cheers!

Beach Bum

A Griffin or Be Cool radiator will help a little bit, but not that advertised and guaranteed 20 degrees, simply because you already have an aluminum radiator. But I like them and think they are good modifications... but expensive.

Obviously make sure your radiator is clean on the outside... blow it out and clean it frequently with water.

Water Wetter will help a bit I guess, but not much, maybe a degree or so is what I've noticed.

A 160 stat might help, but keep in mind a stats main purpose is to insure the water temp stays a mininum of 160. But it will help simply because it will get the water circulating sooner thus slowing down the heat-up.

What I found very helpful as well is to wire up a switch to my dash that manually turns on both fans at any time that you wish... mine are always on. I can click the switch off and it will simply return to letting the ecm determine fan turn on and off.

There is a wiring kit available from Mid America to help with this, I think its only around $ 10 or so.

hope this helps a bit.

Cheers,
Beach Bum

Togo

Jason, you can get the water wetter from mid america, its in their catalog. also may want to try your local parts store, they have something called hyper-lube (does the same as water wetter & looks like antifreeze) i have 2 bottles in my radiator now and have not had significant heat up problems in a while.

ROADAPPLE

Check out WaterWetter at Redlineoil.com. Discount Auto Parts also carries it at 6-8 dollars a bottle. It works best when used with straight water. If freezing is a consern use 20% Anti-freeze.

DW

Nathan Plemons

An electric water pump MIGHT help. Most people run them because they are 9 hp straight to the wheels on a 350, but it would run at a constant speed, maybe high enough to keep you cool. I just don't know. I know my 350 doesn't run any hotter with it.

ham

Try a Stuart Hi-Volume water pump.

1991Z07

Jason,
There is one "direct-replacement" radiator on the market that is all aluminum. The stock Corvette radiator has aluminum cores, but the tanks are plastic. This is typically where the failure point is.

Fluidyne makes a radiator to fit our cars. They use a single 1.5" (38MM) core-tube and I'm told it will handle up to 450-475 HP. Cost I believe is $612 for manuals & $625 for automatics. Their URL is http://www.fluidyne.com/highperform.html

I feel your pain. I'm running a little on the warm side as well. I'll be replacing my cooling system with one from Evans http://www.evanscooling.com/main21.htm

I'm got work in progress on a 427 SB to drop in mine. Fluidyne tells me that their radiator won't handle the horsepower my engine is going to make. We'll be in the 550-600 HP range, and for that we need increased capacity. A 3 or 4 core is the only way to get there.

Some other things to try are some of the most basic.

1) Remove the radiator and clean out all the crap that has built up down there over the years. You'll be surprised what you find.

2) Flush the radiator.

3) When installing the radiator back in the car, seal all the air spaces around the sides of the unit, front and rear (in front and where the shroud meets it in back). This will force more air to go through the core, and should be good for a few more degrees.

4) Water Wetter is good to use, not sure exactly why (I'm no chemist, and I hated chemistry in school). It does work. It will drop it a few more degrees.

5) If that doesn't get you where you want, you may need to add a "catch-tank" up in the nose. This would add another 1-2 gallons of coolant. You would have to put it in-line with the return side of the system...coming out of the radiator and going back to the motor.

Another fix I've seen is a disk in the return line with a hole cut into it. This forces the water to stay in the radiator a little longer and cool a bit more before it returns to the engine. It works really well on big-blocks.

If all the above fail, you will need to go to a radiator with higher cooling capacity.

Good luck

89vette

Joe. I'll check out that Fluidyne radiator. Thanks for the link. I don't have those plastic tanks like you. I have an 89. My radiator sits straight up and down. I think the 90 and 91's are better with the tilted radiator. So I have read. I'm going to check the area between the condensor and radiator. I had that out when I put a cam in about 4 years (12000 miles) agao. None the less, I'm going to check it. I might also they the 160 stat and turn the fans on at 165 to give it more room to climb. The motor ran fine at 227 with no pinging etc, but it just makes me a litte nervous. I rarely run the AC so 95% of the time its no problem. BTW, I have all my parts for the Corsa cat back with dual random cats like you did. I have the shop all picked out and went there to go over what I wanted done. I just need to take it up and drop it off. I hope it quiets it down a bit cause right now its a little noisy for me.

Thanks
Jason

1991Z07

You won't believe the difference.

You'll actually be able to carry on a conversation without yelling, and will be able to hear the stereo without cranking it all the way up.

It still sounds wonderful cracked wide open as well.

J Z06

Went to the store today with mine... supposedly over 100 deg(heat index on the news said 110 with humidity) I had the a/c on for the first time in over a year...temp stayed right in the middle of the gauge. Guessing 180?

vettewally

The best cooling mod I have ever made is the water pump pulley from evans cooling it really helped my supercharged 383and it still has the stock radiator.It's about $100 and is better than spending all the money for a radiator.Also having to cut the shroud for a bigger radiator is a PIA.

89vette

Pure water is out of the question. I have a heated garage and never drive teh car in the winter but I WON't take the chance. I'll check out evans cooling. Does the pulley make the water pump spin faster? I would guess so. Anyone have experiance with their coolant?

Joe, yes I'm hoping I have the same result as you did with the Corsa cat back. The resonator must deaden sound more than I thought.

88WHITE VETTE

What's your engine oil temp?
At times, you can "help" your engine maintain lower temps by cooling your oil down. Did you kept your stock oil cooler after 383? I took my out and after my 383 went in, I am running slightly high(200~230) on oil temp and now installing aftermarket oil cooler. My coolant temp is great, I usually run around 185~205 with bouth fans on and stock radiator with bypassed transmission cooler, I have seperate one from tranny to the front of the radiator. O yeah I don't have my A/C system and no condencor in front of the radiator.
Ziggy

Not Stock

I see that you have a lot of changes to your car. Something to check in addition to the advice already given would be to be sure that you are not lean at idle and cruse conditions as that could add to the car running hot.

AquaMetallic94LT1

I think you should stick with the factory recommended anti freeze ratio and concentrate on the rest of the cooling system.

1. Replace the radiator cap if the one you have is more than a few years old. It can leak and the system can suck air through it instead of anti freeze from the nose resevour.
2. Make sure the resevour tank by the cowl is full when the engine is cold. Make sure the resevour in the nose if filled to the full hot level when the car is cold.
3. Make sure you have the thermostat you think you have.
4. Make sure the timing is set correctly.
5. Make sure the ECT sensor is working correctly.
6. Make sure the hose clamps are tight and the bleeder valves.
7. Get a waterpump that flows more coolant if you notice the car cools when the engine is reved.
8. Make sure your exhaust is not plugged. I don't think yours is since you have long tubes etc.
9. Make sure the fans are working correctly.
10. Make sure the radiator is not clogged.

A 396 is going to run a bit hotter than the 350 because of the extra hp it takes to handle the added friction of the larger displacement. I am not sure how this translates to running temperature though.

Check to see if any of the hot air from the engine compartment is getting recirculated back through the front end. Reach up inside the front side of the AC radiator when the car is hot and feel for any warm air. Make sure all the ducting is in good shape too.

Go for the water wetter too.

Good luck.