Question: Aluminum radiators

[boomdriver]

After driving around and already hitting 230 degree temps, (with the stock tuning) I'm looking at better cooling systems.
My question is to anyone that has experience with these, is what can be expected out of an all aluminum double row or triple row radiator?

is cooling much better? or a little better? do either fit the original space with no condensor mods required?

There are some good prices on Flea-Bay for 3 row, all welded aluminums, and my current brass unit is just not going to cut it in this enviroment with the hi humidity and ambient temps. Traffic is as bad as hi-performance driving as far as cooling/ heat generation.

With the possibility of some form of charger looming in the future, I want to address the heat issue now.I may postpone paint to turbo-charge....Priorties, ya know.
I'm sick of kids in dodge chargers wanting to challenge me at stop lites.

What are the thoughts on the 2 row and 3 row aluminums?

 

[John Dingman]

There is a big difference in our aluminum radiators to your stock radiator. You should have an aluminum radiator now. C4-C6 all have 1" aluminum radiators with plastic tanks. We double the size of the core with 2-1" tubes and full welded aluminum pressed formed tanks. We here anywhere from 20-30 degree drop. Hopefully others will chime in with there results. These are a direct fit replacement no modifications required.

DeWitts - Product Detail

Thanks,
John

 

[Hib Halverson]

Why not, first, try doing some service work to reestablish proper cooling? If the engine is not significantliy modified, the problem might be service related.

Check the cooling stack to make sure the space in front of the hvac and between the hvac and the radiator are clear of debis.

Check to make sure the existing front air dam is in place and in good condition.

Make sure the cooling fan is working properly. If the car has an auxilary cooling fan, as some Z51s so, make sure it's working.

If you still want an aftermarket radiator, as John Dingman suggests, DeWitts is a good choice.

 

[joshwilson3]

Why not, first, try doing some service work to reestablish proper cooling? If the engine is not significantliy modified, the problem might be service related.

Check the cooling stack to make sure the space in front of the hvac and between the hvac and the radiator are clear of debis.

Check to make sure the existing front air dam is in place and in good condition.

Make sure the cooling fan is working properly. If the car has an auxilary cooling fan, as some Z51s so, make sure it's working.

If you still want an aftermarket radiator, as John Dingman suggests, DeWitts is a good choice.

What is wrong that means there is a cooling problem? 230 is normal temps. The way GM designed it. If you let you car sit idle with the AC/Heat off. It will get to 230 then the fan turns on.

Sounds to me like the OP has a normal running cooling system from what he has described.

Also, on those special radiators. I've read of some who put them in with no change in their coolant temps.

 

[boomdriver]

I do not have a stock radiator. The current unit is a brass aftermarket with larger tanks, single row. Since any 2 or 3 row comes in aluminum, thats what I am inquiring about.


The engine is not stock....not blown, not No2, but is bored, bigger pistons with slightly higher compression ratio,(close to 10.5:1) ported & port matched from TB to intake valve, and larger TB. The electronic control has been returned to stock trying to get a legitmate smog cert. The performance tuning will be restored soon.

Normal operating temps are subject to fan initiation, which is 230-8? or in that neighborhood. I would prefer to sit in traffic at under 220 and much less while cruising...if thats possible.

The thick nasty humid air along the Gulf Coast is another thing altogether. Much harder to have good heat exchange than the dry warm air of the dessert. In fact, the differential seems almost nil due to the high humidity levels around here.

I have a lifelong background in hydraulics and have come to understand that it is easier to keep something cool, than it is to cool it off later...

 

[joshwilson3]

I do not have a stock radiator. The current unit is a brass aftermarket with larger tanks, single row. Since any 2 or 3 row comes in aluminum, thats what I am inquiring about.


The engine is not stock....not blown, not No2, but is bored, bigger pistons with slightly higher compression ratio,(close to 10.5:1) ported & port matched from TB to intake valve, and larger TB. The electronic control has been returned to stock trying to get a legitmate smog cert. The performance tuning will be restored soon.

Normal operating temps are subject to fan initiation, which is 230-8? or in that neighborhood. I would prefer to sit in traffic at under 220 and much less while cruising...if thats possible.

The thick nasty humid air along the Gulf Coast is another thing altogether. Much harder to have good heat exchange than the dry warm air of the dessert. In fact, the differential seems almost nil due to the high humidity levels around here.

I have a lifelong background in hydraulics and have come to understand that it is easier to keep something cool, than it is to cool it off later...

At least on my 89. The main fan turns on at 228 or 230. If you have the extra fan. Then that turns on at 238. I think that fan is just a backup. So, it shouldn't normally come on unless you have an overheating problem.

If you want it to run cooler. Then I think you will have to reprogram the fans to turn on sooner.

If you have the auxiliary fan. Then you could get a switch from Mid America than turns that fan on at 200 and off at 185. If you don't have the auxiliary fan, then I think you have to also get the conversion harness.

I've never installed this but something to look into on the cheap:

C4 C3 Corvette Cooling Fan Switches 1981-1995 - Mid America Motorworks

I believe the part number is 609-106 at Mid America.

 

[boomdriver]

I already have proms, switches etc that do all that. It is irrelvant if the heat generated is more than the potential heat exchange.
That is why I am asking if 2 or 3 row aluminum radiators actually have a significant improvement in heat exchange.
I am NOT saying that mine does not work right. It works exactly as the factory programming dictates.

Back to the original QUESTION.........

Does ANYONE have any experience with 2 or 3 row aluminum radiators and how do they compare to others?

 

[joshwilson3]

I already have proms, switches etc that do all that. It is irrelvant if the heat generated is more than the potential heat exchange.
That is why I am asking if 2 or 3 row aluminum radiators actually have a significant improvement in heat exchange.
I am NOT saying that mine does not work right. It works exactly as the factory programming dictates.

Back to the original QUESTION.........

Does ANYONE have any experience with 2 or 3 row aluminum radiators and how do they compare to others?

When does your fan turn on?

 

[Schrade]

What is wrong that means there is a cooling problem? 230 is normal temps. The way GM designed it. If you let you car sit idle with the AC/Heat off. It will get to 230 then the fan turns on.

Sounds to me like the OP has a normal running cooling system from what he has described.

Also, on those special radiators. I've read of some who put them in with no change in their coolant temps.

Yes, it's normal, IF the cooling system cools it within a few minutes, BACK to 218, from 228 (I think that's spec).

My L98 would hit the fan demand temp, and if in the driveway just idling in park, would take it back around 220 in a few minutes. My LT1 came on at exactly 228, and would shut off in no more than 3 minutes, at 218 on the button. In traffic, it would take a few minutes longer, except stop n go with A/C, heat of summer it would stay that way till at speed.

 

[orlandjoe]

I have installed a BeCool radiator in my 1966 coupe with a 454 big block. It seldom gets over 210 on the temp gauge. I use both an engine flex fan and an electric fan in front of the radiator. My electric unit has a hidden on/off switch so I can turn it off when cruising at highway speed and turn it back on when stuck in traffic.

 

[Schrade]

I have installed a BeCool radiator in my 1966 coupe with a 454 big block. It seldom gets over 210 on the temp gauge. I use both an engine flex fan and an electric fan in front of the radiator. My electric unit has a hidden on/off switch so I can turn it off when cruising at highway speed and turn it back on when stuck in traffic.

2 x 4? Mechanical secondaries? 2 BIG deuces?

 

[orlandjoe]

dual edelbrock 600 cfm carbs, direct linkage (not progressive) so both carbs are working all the time. vacuum secondaries. great off the line.

 

[Brian Smith]

Boomdriver I live in north Texas and last summer I installed a 160 degree thermostat in my 93 LT1 because the normal operating temperatures made me very nervous. As mentioned by others it would heat until it got to about 230 the fan(s) would come on and it would drop to about 218 then the fans would turn off. I am an old Chevy guy and temps like that seem destructive because if a problem occurs there is so little margin between 230 to 260 (red line).

About that same time I installed a Hypertech chip that had firmware conventions that caused the fans to turn on about 185. With the A/C on the fans are automatically enabled and it never exceeds about 178. The difference of 18 degrees I attribute to the T-Stat and I believe the intention is that the T-Stat starts to open at 160 only. Not at what degree it is fully opened. That seems to be about 178 in my case. Plenty close for my needs though.

My temp runs in the neighborhood of 175 +/- 8 degrees (without the A/C on) on year round. I will say that it isn't much fun (lacking the higher coolant temp in the winter) but I was able to live with it even during the snows of this winter. Next year I may change the stat during the winter.

I drive this thing every day to work and the lower temps are a pleasure. Lower cabin temp and less concern is a plus as well.

You have to manage the entire system to get the results you want. Get a more robust radiator and leave the original T-Stat in place and it WILL run at the original temp and you have wasted BTU dissipation capacity. Change the T-Stat (to a lower temp unit) and have clogged radiator tubes or debris in the core it will overheat since you can’t dissipate the BTUs. Change what you want but realize these things interrelate effectively.

My point in all this is, if your radiator and condenser coils are free of debris there is more than enough capacity in the stock cooling system to keep the average car cool. If the stock thermostat is a 228 degree (or whatever temp is spec'd by Chevy) your engine WILL run at 228 as long as the stat operates as designed (or until failure). If your computer intends for the fans to come on at 230 and turn off at 218 then that is what will happen. The presumption is the T-stat will hold the engine at the set point and the fans will do just enough to dissipate any excess to keep the engine demand set point satisfied.

By the way, do not make the mistake of ordering the Hypertech cooling fan thermostatic block switch. It is about $50 and after buying the part's (T-Stat, Chip and thermostatic switch) from Jeggs and couldn't see where to install the switch (NPT threads didn't match any block holes into the coolant water) I called Hypertech and spoke to an old hand there and he said not to install it since the chip uses the stock onboard block temperature sensors to trigger the fan operation anyway. He was correct and I happily sent it back and got my $50 back and went happily off on my way. Give me a holler if I can help further.

 

[joshwilson3]

Boomdriver I live in north Texas and last summer I installed a 160 degree thermostat in my 93 LT1 because the normal operating temperatures made me very nervous. As mentioned by others it would heat until it got to about 230 the fan(s) would come on and it would drop to about 218 then the fans would turn off. I am an old Chevy guy and temps like that seem destructive because if a problem occurs there is so little margin between 230 to 260 (red line).

About that same time I installed a Hypertech chip that had firmware conventions that caused the fans to turn on about 185. With the A/C on the fans are automatically enabled and it never exceeds about 178. The difference of 18 degrees I attribute to the T-Stat and I believe the intention is that the T-Stat starts to open at 160 only. Not at what degree it is fully opened. That seems to be about 178 in my case. Plenty close for my needs though.

My temp runs in the neighborhood of 175 +/- 8 degrees (without the A/C on) on year round. I will say that it isn't much fun (lacking the higher coolant temp in the winter) but I was able to live with it even during the snows of this winter. Next year I may change the stat during the winter.

I drive this thing every day to work and the lower temps are a pleasure. Lower cabin temp and less concern is a plus as well.

You have to manage the entire system to get the results you want. Get a more robust radiator and leave the original T-Stat in place and it WILL run at the original temp and you have wasted BTU dissipation capacity. Change the T-Stat (to a lower temp unit) and have clogged radiator tubes or debris in the core it will overheat since you can’t dissipate the BTUs. Change what you want but realize these things interrelate effectively.

My point in all this is, if your radiator and condenser coils are free of debris there is more than enough capacity in the stock cooling system to keep the average car cool. If the stock thermostat is a 228 degree (or whatever temp is spec'd by Chevy) your engine WILL run at 228 as long as the stat operates as designed (or until failure). If your computer intends for the fans to come on at 230 and turn off at 218 then that is what will happen. The presumption is the T-stat will hold the engine at the set point and the fans will do just enough to dissipate any excess to keep the engine demand set point satisfied.

By the way, do not make the mistake of ordering the Hypertech cooling fan thermostatic block switch. It is about $50 and after buying the part's (T-Stat, Chip and thermostatic switch) from Jeggs and couldn't see where to install the switch (NPT threads didn't match any block holes into the coolant water) I called Hypertech and spoke to an old hand there and he said not to install it since the chip uses the stock onboard block temperature sensors to trigger the fan operation anyway. He was correct and I happily sent it back and got my $50 back and went happily off on my way. Give me a holler if I can help further.

"If the stock thermostat is a 228 degree"

You mean stock thermostat is 195.

But anyways, he's got an 87. If he also has the extra fan. Then I think it would be cheaper and easier to install that fan switch I posted from Mid America. As it says it turns the fans on at 200. But I'm just going by what it says. I think it will still work if he doesn't have the extra fan, just needs to get the wire harness as well.

 

[joshwilson3]

There is a big difference in our aluminum radiators to your stock radiator. You should have an aluminum radiator now. C4-C6 all have 1" aluminum radiators with plastic tanks. We double the size of the core with 2-1" tubes and full welded aluminum pressed formed tanks. We here anywhere from 20-30 degree drop. Hopefully others will chime in with there results. These are a direct fit replacement no modifications required.

DeWitts - Product Detail

Thanks,
John

I'm betting if I put your radiator in my 89. That sitting idle with the AC and Heat off. The car will still get to 228 till the fans kick on. I highly doubt the temp would stop at 200.

If someone notices a drop in coolant temp with your radiator. Then I'm betting their old radiator was clogged or wore out. Which is why it was probably replaced to begin with.

 

[boomdriver]

When does your fan turn on?

In the stock configuration they come on the same time/temp as everyone elses. 228-30 then approx 238 for the HD, and that also has a manual over-ride switch that can be activated anytime. The HD fan is used more to keep the condensor from over-heating.

In the performance configuration (my non-stock engine) the main comes on at 185 then off at 166 with the custom prom that was made. The fuel/timing curves were also set in THAT prom to take advantage of the lower temps. The key to stable engine temps is a thermostat that matches fan activation. The key to acceptable "normal operating temps" is having the ability to remove heat faster than it can be generated.

The problem is, that the bigger engine generates more heat than the system can exchange.

Again, it is BY FAR easier to keep something cool than it is to cool it down after it has over-heated.

I can get my fans on anytime. Thats not rocket science. But when heat is being placed into the system faster than it can be removed, THAT is my problem. Once mine gets to 230+ degrees, its not going back down easily. Bigger engines create more heat.

I am using the brass single row radiator because its tanks are bigger and it holds more coolant. The theory being that the coolant only gets cooled when its in front of the fan...so when there is more coolant in the radiator, there should be more heat being removed. It does a better job than the stock radiator with its tiny plastic tanks. But,Thats not good enough. There needs to be more heat exchange from airflow.
I've been driving c-4's since 1987 and have been 'round the block with these issues. I do KNOW that a better water pump is part of the solution. Thats on the shopping list. The Edlebrock aluminum body/cast impeller is a wonderful unit. Expensive, but it circulates water at idle like the stock pump does at 3000 rpm.

The limited space ahead of the condensor does not allow for a fan that has direct flow to the radiator. You cannot fit a fan between the condensor and radiator. Believe me, I've tried.
The C-4 radiator gets half of its fresh air thru the baffles that go around the condensor. The same route that trash will take. The HD fan does not have enough force to push lots of air to those side baffles because it is not in a shroud. I wish it were.

So, the main sucker fan is 95% of the cooling efficiency and that is all about having enough airflow (due to the nice tight shroud) to collect heat and remove it. I need more heat exchange surface OR more air to move thru the current amount of surface area. Thats why I ask about how well 2 or 3 row radiators actually work.
Increased vehicle speed MAY create more airflow, but it ALSO generates more heat by increased engine effort. My engine heat shoots upward above a consistant 2500 rpm.The system will keep up when the ambient temps are 85 or less. Otherwise, temps go up and stay up. And yes, the air-dam is fine.

heat exchange is what I'm interested in. Either a more efficient exchanger or better airflow. Air will be tougher to get because there is limited space for a bigger fan and GM did an excellent job designing the main fan and its shroud. It's as efficient as that amount of space will permit for a fan.

So, there is nothing "wrong"...its just not good enough. After having wrecked heads 2 times in the past from over-heating incidents, I am not willing to accept 230 degrees with the zero tolerance for error that 230+ offers.
AT 250 degrees and rising, you're going to start doing damage to something either by the heat or from coming down from that temp. Believe me, when cruising @ 230 and you blow a big hose, it takes 5 seconds to hit 250+ at freeway speeds. Stuck in heavy traffic on an overpass? You;re toast.
Temps above that are fatal to dry aluminum heads. been there, done that.

All I want is a stable operating temp thats not lower than 185 and not higher that 210. Right around 195-200 in the summer would be friggin fantastic. 210 would even be acceptable.

 

[joshwilson3]

In the stock configuration they come on the same time/temp as everyone elses. 228-30 then approx 238 for the HD, and that also has a manual over-ride switch that can be activated anytime. The HD fan is used more to keep the condensor from over-heating.

In the performance configuration (my non-stock engine) the main comes on at 185 then off at 166 with the custom prom that was made. The fuel/timing curves were also set in THAT prom to take advantage of the lower temps. The key to stable engine temps is a thermostat that matches fan activation. The key to acceptable "normal operating temps" is having the ability to remove heat faster than it can be generated.

The problem is, that the bigger engine generates more heat than the system can exchange.

Again, it is BY FAR easier to keep something cool than it is to cool it down after it has over-heated.

I can get my fans on anytime. Thats not rocket science. But when heat is being placed into the system faster than it can be removed, THAT is my problem. Once mine gets to 230+ degrees, its not going back down easily. Bigger engines create more heat.

I am using the brass single row radiator because its tanks are bigger and it holds more coolant. The theory being that the coolant only gets cooled when its in front of the fan...so when there is more coolant in the radiator, there should be more heat being removed. It does a better job than the stock radiator with its tiny plastic tanks. But,Thats not good enough. There needs to be more heat exchange from airflow.
I've been driving c-4's since 1987 and have been 'round the block with these issues. I do KNOW that a better water pump is part of the solution. Thats on the shopping list. The Edlebrock aluminum body/cast impeller is a wonderful unit. Expensive, but it circulates water at idle like the stock pump does at 3000 rpm.

The limited space ahead of the condensor does not allow for a fan that has direct flow to the radiator. You cannot fit a fan between the condensor and radiator. Believe me, I've tried.
The C-4 radiator gets half of its fresh air thru the baffles that go around the condensor. The same route that trash will take. The HD fan does not have enough force to push lots of air to those side baffles because it is not in a shroud. I wish it were.

So, the main sucker fan is 95% of the cooling efficiency and that is all about having enough airflow (due to the nice tight shroud) to collect heat and remove it. I need more heat exchange surface OR more air to move thru the current amount of surface area. Thats why I ask about how well 2 or 3 row radiators actually work.
Increased vehicle speed MAY create more airflow, but it ALSO generates more heat by increased engine effort. My engine heat shoots upward above a consistant 2500 rpm.The system will keep up when the ambient temps are 85 or less. Otherwise, temps go up and stay up. And yes, the air-dam is fine.

heat exchange is what I'm interested in. Either a more efficient exchanger or better airflow. Air will be tougher to get because there is limited space for a bigger fan and GM did an excellent job designing the main fan and its shroud. It's as efficient as that amount of space will permit for a fan.

So, there is nothing "wrong"...its just not good enough. After having wrecked heads 2 times in the past from over-heating incidents, I am not willing to accept 230 degrees with the zero tolerance for error that 230+ offers.
AT 250 degrees and rising, you're going to start doing damage to something either by the heat or from coming down from that temp. Believe me, when cruising @ 230 and you blow a big hose, it takes 5 seconds to hit 250+ at freeway speeds. Stuck in heavy traffic on an overpass? You;re toast.
Temps above that are fatal to dry aluminum heads. been there, done that.

All I want is a stable operating temp thats not lower than 185 and not higher that 210. Right around 195-200 in the summer would be friggin fantastic. 210 would even be acceptable.

Ok. I was thinking your car was stock. Yes 230 is normal for a stock car.

Just odd that your fan turns on at 185, but the temp will still go to 230.

By the way, that backup fan shouldn't turn on. As the temps shouldn't get to 238 unless there was a problem. I guess it's nice to have in case that happens.

Yeah, in that situation with a modded engine and temps going higher even with the fan going, you need a better cooling setup than stock. I don't know if the double row would help, but you could give it a try. I would probably avoid those Ebay radiators, as I'm betting their quality isn't good. You could try a Dewitts.

Your fan must run all the time if it comes on at 185, but the temps still go up to 230?

Maybe you can get a deal on a Dewitts here:

84-89 Dewitts Radiator New in Box For Sale! - Corvette Forum

 

[Schrade]

I'm betting if I put your radiator in my 89. That sitting idle with the AC and Heat off. The car will still get to 228 till the fans kick on. I highly doubt the temp would stop at 200.
.

This is exactly right.

It has been debated forever.

But one realization has just come to me, and this is in-depth intuition @ it's finest (since I do say so myself yUp):

The 160 thermostat means it will open at 160. This means it will take LONGER to warm up to NOMINAL (optimal) operating temperature uH HUh.

And here's the gem: Longer warm up time means more time operating in OPEN LOOP, during which fuel trim is max pulsewidth. Unless the hammer is on the floor, that means LESS FUEL MILEAGE, MORE CARBON BUILDUP, REDUCED LIFESPAN OF CATS (lemme' think some more on whatever else the ramifications are HUH???).

Wiz OUT

 

[joshwilson3]

This is exactly right.

It has been debated forever.

But one realization has just come to me, and this is in-depth intuition @ it's finest (since I do say so myself yUp):

The 160 thermostat means it will open at 160. This means it will take LONGER to warm up to NOMINAL (optimal) operating temperature uH HUh.

And here's the gem: Longer warm up time means more time operating in OPEN LOOP, during which fuel trim is max pulsewidth. Unless the hammer is on the floor, that means LESS FUEL MILEAGE, MORE CARBON BUILDUP, REDUCED LIFESPAN OF CATS (lemme' think some more on whatever else the ramifications are HUH???).

Wiz OUT

I just use a 195 stat. You always hear the debate about GM runs their cars too hot, etc. My 89 Firebird has 170k miles running on a 195 stat. It has even been overheated a few times. So, I don't really see the point in trying to lower the temps if you can get 200k miles out of it. There are several GM cars that the engine goes over 200k. What benefit would running the engine cooler provide? Though, I can understand someone wanting to adjust their temps if they have a modded or aftermarket engine.

Most people don't even keep their cars for that long to get over 100k miles.

I do agree that you shorten the window to redline if you run the car at the stock temp vs. lower. But I'm betting in an overheating situation, that extra cushion of running the temp lower won't provide alot of extra time. Usually people notice they are running too hot is when they see steam. So, at that point, it doesn't matter if it was supposed to be running at 200 or 230, you didn't notice it till after it already was overheating.

After my Firebird overheated a few times many years ago. I alway keep an eye on my gauges while I drive.

Also, actually I believe you go into closed loop way before you hit 160. So, I don't think the open loop time would be any different if you already are in closed loop by the time you get to 160.

 

[D95]

I recently put in a dewitts radiator. The temps are the same (95 LT1)as my stock radiator. My system is all stock with the 180 stat. The dewitts is a great radiator. If you want the car to run cooler then you should chane the fan settings and use a 160 dg. stat. You can turn on the a/c during traffic-that will turn on both electric fans to keep it slightly cooler. These cars were designed to run hot.