Radiator choice

[bbrriiaann1973]

What is the largest aluminum radiator that I can for my 70 c10? I have a copper 4 core radiator and I need it to run a little cooler.

The truck has a 383/700R4 with A/C with dual electric fans and it will run hot in stop and go traffic with A/C on during the summer.

[clay68c10]

It’s a generic answer, but whatever size matches the opening in the core support. You can always fab brackets to mount it.

That said, how old is the 4 row? With a good fan or fans and shrouding, it should keep that 383 cooled off.

When I lived in Dallas I had a .030 over 454 with AC and it ran steady and happy at 200-205 with a new stock size 4 row copper and a Lincoln MK8 fan. This includes summertime commuting 20+ miles at 5pm when it was over 100 deg.

[bbrriiaann1973]

200 is not acceptable. Keeping the truck at 190 is pushing it. My is for it to run 180 with a/c on during the summer.

6 core aluminum radiator with huge tanks. If this could be a option.

[ZEKE68]

I am running a two row aluminum with plastic tanks on my .030 over 454. With ac on in 94 degree weather it runs 180 degrees. I have not been in stop and go traffic with it yet though. I ran a 19 1/2 inch fan with a fan clutch, and tightened up the air path as much as possible so it pulls through the radiator.

[clay68c10]

Give it a shot, but I'm doubting that you will be able to accomplish 180 under those conditions. The condenser is running at 160-200+deg depending on head pressure and the cooling air has to pass thru it first.

My stockish 93 350 TBI truck runs at 195-205 in the summer here (a/c on) and it's just fine. I wouldn't be scared of 200ish.

Are you having detonation or fuel percolation problems when it gets hot?

[PepperTreeGarage]

I'm going with one of these. They were at the Labor Day Cruise in Costa Mesa. I liked the quality that I saw. https://www.coldcaseradiators.com/chevy/gmc-truck/

[72c20customcamper]

Originally Posted by bbrriiaann1973

What is the largest aluminum radiator that I can for my 70 c10? I have a copper 4 core radiator and I need it to run a little cooler.

The truck has a 383/700R4 with A/C with dual electric fans and it will run hot in stop and go traffic with A/C on during the summer.

What are you considering hot.? Where is your temp sensor located? Head temps will somewhat hotter than water temp. Head can be 205 and water will be 10 to 15° cooler. I have dual gauges on my chevelle one in the head and one in the manifold. The head can be slightly over 200 before the 190 sensor in the rad kicks in the fans. Also do you have any type of shroud on the radiator? A lot af air can bypass the radiator if not.

I bought a DeWitt for the chevelle I also have a cold case for my truck with dual fans and shroud but the truck runs cool with the factory setup. So If I install the BBC I had built for another project that went south I may install it then

[bbrriiaann1973]

I live in phx az that's the first problem so when its 115 during rush hour I want to know that I can keep it in the 180s.

Second the 383 that i have is a .60 over 383 so the cylinders are thin and it runs hotter then a normal 350 would. That's why I want to make it run as cool as possible.

[HO455]

There are some other things to look before dropping 8 bills or more on the ultimate radiator. What is the CFM rating of the fans? Puller or pusher? What kind of shroud are they mounted on? How well sealed is your current radiator to the core support? Do you have radiator overflow tank installed? When you say thin cylinder walls how thin are you talking?
Ideally when idling you want to minimize the air flow from the engine compartment back into the fans. In other words the fans create a low pressure area in front of the radiator and that can cause hot air from the engine side of the radiator to be pulled back through the front of the radiator. The area above the core support is not sealed from the factory on our trucks and when the truck is stopped there is nothing to prevent the hot air from being sucked forward through the radiator. You can't cool with hot air. Seal the top of the core support to the grille and you stop this air flow. Putting an air dam under the core support will help with hot air coming from below. When driving avoid being less than 15 feet from the vehicle in front of you if it has exhaust out of the rear. (I know it sound odd but we have proved this to be true even when running at 50 MPH. We have a GTO with electric fan that will run down the highway all day long in 80 degree heat with the fan turned off. Get to close to a vehicle and the temperature starts to rise and the fan has to be turned on. Get behind a vehicle with the exhaust exiting the side and the temp rises about 5-10 but no more.) More hot air that kills your temperature delta and causes the engine to run warm. Ditch the factory temp guage and install a large high quality aftermarket guage. Preferably in the outlet of the engine to the radiator so you see the temperature of the water going to the radiator. Then you can add a temporary guage into the radiator outlet to the engine and confirm how much the temperature is dropping after passing through the radiator.
Post some photos of your setup. We do like pictures!

[weq92f]

Originally Posted by HO455

There are some other things to look before dropping 8 bills or more on the ultimate radiator... <snip> ...The area above the core support is not sealed from the factory on our trucks and when the truck is stopped there is nothing to prevent the hot air from being sucked forward through the radiator. You can't cool with hot air. Seal the top of the core support to the grille and you stop this air flow.

Good points... Many of us have those panels that "pretty" up the engine bay by covering the space between the top of the grill and the top of the core support. Mine are not perforated or louvered and extend the entire width of the truck establishing a good "seal" between inside the bay and outside the bay.

I think these can be had for cheap or even fabricated if you have some skills. Definitely worth the effort/cost if you're worried about the heat.

-klb

[MARKDTN]

Originally Posted by bbrriiaann1973

200 is not acceptable. Keeping the truck at 190 is pushing it. My is for it to run 180 with a/c on during the summer.

6 core aluminum radiator with huge tanks. If this could be a option.

Not sure why you say that? 195-200 is not bad. GM doesn't even sell 180 t-stats any more. If you have 50/50 antifreeze the boiling point is in the mid 200s so you have plenty of cushion. You actually run more efficiently and get more water out of the oil if it runs hotter than 180.

[Stocker]

A few pics of your current set-up would be helpful. There are guys here that have fought the same battle you're dealing with, and might see something that you have missed.

[bbrriiaann1973]

Here are a few pics

[Roady’s truck]

Originally Posted by bbrriiaann1973

200 is not acceptable. Keeping the truck at 190 is pushing it. My is for it to run 180 with a/c on during the summer.

6 core aluminum radiator with huge tanks. If this could be a option.

A 4 row that size with a 160* thermostat should keep that motor cool and happy. If it’s running hot with a four row there’s restriction somewhere.

Not enough airflo or water flow or both.

This is with just a radiator and fan shroud. You should not need all kinds of extras.
I ran a 4 row in my Chevelle with a flex fan and Reduced speed pulleys with a 160* stat and 350 ponies .060 over 350. and it never went over 180*. You could put a price of notebook paper on the grill and it would hold it there the at an idle.

[hjewell2]

Originally Posted by Roady’s truck

A 4 row that size with a 160* thermostat should keep that motor cool and happy. If it’s running hot with a four row there’s restriction somewhere.

Not enough airflo or water flow or both.

This is with just a radiator and fan shroud. You should not need all kinds of extras.
I ran a 4 row in my Chevelle with a flex fan and Reduced speed pulleys with a 160* stat and 350 ponies .060 over 350. and it never went over 180*. You could put a price of notebook paper on the grill and it would hold it there the at an idle.

My thoughts also

[bbrriiaann1973]

I only have electric fans. Two of them in fact.

[Stocker]

Can't see the shrouding very well but if it forces most of the air through the radiator, that should do the trick. Any idea what the CFM rating is on the fans? Have you checked temps at multiple areas of the radiator with an IR temp gun? It should be hottest on the driver's side and gradually cool down going towards the passenger side.

[bbrriiaann1973]

2200 cfm per fan

[HO455]

It looks as if you have most of the easy modifications done to ensure cooling. What about the evaporator for the A/C? Is it restricting too much air to the radiator? I see you have aluminum heads. What compression ratio are you at?
I have to admit that if it was 115 outside in traffic and my first gen SBC was below 200 degrees I would be satisfied.

[bbrriiaann1973]

The 383 is built to the hill! Compression is 10.5 to 1

[HO455]

Well you could make a little bit of cooling gain with a large 2 row aluminum radiator. But the next step looks like custom core support time. Every row added to a radiator is less effective than the one in front of it. That's why you don't see radiators with more than four rows.
If I was going down the custom core support road I would go with a 2 row 3 pass radiator aluminum radiator. Hopefully out of a late model vehicle. You loose water volume but gain cooling in that the water passes the fans three times.
Here is a link to larger cooling fans.
http://67-72chevytrucks.com/vboard/s...d.php?t=722863

And a second link on radiators you may not have seen.
http://www.pirate4x4.com/tech/billavista/Cooling/

P.S. The engine sounds fun.

[Myoldtruck]

Did you have the engine dyno tuned since its been installed. There is alot of heat problems related to timing and the engine running lean. Just adding another 2 cents.