Ultimate cooling set up

[Chris Ziemer]

Hi, my 82K5 has a four row radiator, severe duty clutch fan, spal pusher fan, which I think is 1650 CFM and I’m still easily hitting 210 in the California heat. Factory air conditioner obviously gets me there pretty quick.
If money were no option, what would your ultimate cooling set up be? I had electric fans at one point, but they must’ve been very cheap because they really didn’t do any cooling at all. Are there superior electric fans out there that will absolutely keep it cool?

 

[obijuank5]

This is what I have what works well for me in a big block crawler that was also in there when I daily drove it too.

Direct fit Be cool aluminum radiator with their matching fans and shroud with a bottle of water wetter. It has wheeled in Texas heat for many years and held temps even nose up for a while. For what it’s worth the fans are louder than the exhaust lol

 

[nvrenuf]

What makes your fan clutch “severe duty” other than the name? Are you sure it’s physically different than a typical HD unit?

How many blades on the fan?

Do you have the correct shroud on it?

 

[Chris Ziemer]

What makes your fan clutch “severe duty” other than the name? Are you sure it’s physically different than a typical HD unit?

How many blades on the fan?

Do you have the correct shroud on it?

Thanks, correct shroud and a 7 blade. The severe duty spins more aggressively at lower rpm’s. Everything is new by me, just finished the build. New GM 350 as well. Aluminum 4 row.
I do have the factory style AC condenser in front, which can’t be helping anything, but I’m not sure what the alternative is.

 

[tarussell]

There is/was an available S/D fan clutch that specifically noted that it was for a 4.56:1 gear ratio C/K-30 454 application - meaning that it stayed engaged closer to 1:1 aggressively and sustained it longer at constant higher RPM’s too. Meaning there are/were more than one S/D type.

There are differences in the pitch of the blades on those seven bladed fans too - I’ve found that certain ( not all ) 6.2 diesel cab chassis applications are the heaviest pitch and the center hub is stouter as well.

Usually a true big-block four core ( not all four cores are equal ) radiator along with the killer F/C & proper fan/shroud will handle brutal southern heat no matter what ya’ throw at it or stack in front of it.

There’s always the super-wide diesel radiators with matching shrouds - not all core supports have large enough air inlet holes so look out for that.

You could also use a pusher fan up front if desired.

There are several dual electric fan & radiator setups that work great but I just was mentioning what has worked for multiple rides in our circle of wheel’n buddies.


Also, verify that the new F/C is working properly because there’s way too many failures on new parts over the past few years.

 

[Chris Ziemer]

What makes your fan clutch “severe duty” other than the name? Are you sure it’s physically different than a typical HD unit?

How many blades on the fan?

Do you have the correct shroud

There is/was an available S/D fan clutch that specifically noted that it was for a 4.56:1 gear ratio C/K-30 454 application - meaning that it stayed engaged closer to 1:1 aggressively and sustained it longer at constant higher RPM’s too. Meaning there are/were more than one S/D type.

There are differences in the pitch of the blades on those seven bladed fans too - I’ve found that certain ( not all ) 6.2 diesel cab chassis applications are the heaviest pitch and the center hub is stouter as well.

Usually a true big-block four core ( not all four cores are equal ) radiator along with the killer F/C & proper fan/shroud will handle brutal southern heat no matter what ya’ throw at it or stack in front of it.

There’s always the super-wide diesel radiators with matching shrouds - not all core supports have large enough air inlet holes so look out for that.

You could also use a pusher fan up front if desired.

There are several dual electric fan & radiator setups that work great but I just was mentioning what has worked for multiple rides in our circle of wheel’n buddies.


Also, verify that the new F/C is working properly because there’s way too many failures on new parts over the past few years.

Thanks that gives me some things to think about. I’m trying to remember where I got my severe duty clutch from. I think it was Napa. Seems to be pretty stout, but hard to say what percentage it locks up at. And looking at the big block cooling systems is a good idea. A bigger radiator would be great, however, you know those core supports, tiny little openings and the condenser covers the entire opening.

 

[tarussell]

I wheeled my ‘83 K-30 with a big-block and this cooling setup with a condenser covering up everything and not once did it think about gett’n too warm.
I’m talk’n about full on abuse in deep sugar sand hang’n it out in third gear-n-low full throttle ( Q-jet secondaries coming in and out ) and struggling to maintain 2,000~3,500 RPM - just torture and no overheating issues; the setup works !


The extra wide “diesel” radiator also is offered in cab chassis trucks only as an optional upgrade ( RPO “V02” ) but has the correct hose outlets for a BBC instead of the odd sized diesel outlet sizes.

 

[imiceman44]

Hi, my 82K5 has a four row radiator, severe duty clutch fan, spal pusher fan, which I think is 1650 CFM and I’m still easily hitting 210 in the California heat. Factory air conditioner obviously gets me there pretty quick.
If money were no option, what would your ultimate cooling set up be? I had electric fans at one point, but they must’ve been very cheap because they really didn’t do any cooling at all. Are there superior electric fans out there that will absolutely keep it cool?

210 is not bad if it stays there with A/C on on days like today. If it's still climbing after 210 then I would be worried.

 

[nvrenuf]

The extra wide “diesel” radiator also is offered in cab chassis trucks only as an optional upgrade ( RPO “V02” ) but has the correct hose outlets for a BBC instead of the odd sized diesel outlet sizes.

That is excellent info! I had to have the outlets on mine changed to fit the 454 hoses.

 

[tarussell]

That is excellent info! I had to have the outlets on mine changed to fit the 454 hoses.

I wish I knew this when you were upgrading your radiator - the learning and information curve is always evolving…

 

[Chris Ziemer]

I’m seeing some $600-$1000 radiators with 1 inch and 1 1/4 tubes. The one I have now is 5/8 max. Now I know the coolant can only circulate as fast as the thermostat will allow to pass, but maybe that’s part of the answer.

Would you agree that would be a good start? Getting a four row with at least 1 inch tubes? I mean, I’ve been through some radiators. But nothing like 1 inch tubes.

 

[Chris Ziemer]

210 is not bad if it stays there with A/C on on days like today. If it's still climbing after 210 then I would be worried.

And that’s if the gauge is even correct. I’m going off the original gauge which has a 210° line. Honestly, without the pusher fan, I’m sure it go over 210 and may or may not occasionally do that anyway. I’m just looking for a bulletproof cooling system. I hate running hot. Agree 210 is not that bad, but it was only like 90 here today.

 

[Wes Harden]

I have been going over my cooling system for a couple years now, AZ summers and the ac push my temps into the low 200's. Today in fact I ran 1/2 gauge all the way home in 110° with the ac blowing sub 60° front and rear. I have a 10" pusher that runs any time the ac clutch is powered. The Pusher fan actually only benefits the ac temp, and not really helpful for engine cooling.
I have 5, 6, and 7 blade fans, AC Delco, US Midwest, Hayden, Duralast, hd and severe duty fan clutches, I have a pile of clutches and a stack of fans. the results always about the same. Also my trans cooler is not through the rad, and I have an external oil cooler.

I am going to do the Windstar fan conversion. Mostly because I have found that I run a trail and the fan clutch fails, one trail one fan clutch, has been this way since I started doing more than fire roads.
I have been procrastinating the Windstar conversion, 2 reasons atm one I want to use a high pressure ac trinary switch to run one of the 2 fans. This will turn the fan only when high side pressure are over a certain psi. I pretty sure I bought one but can't find it atm, and two the existing high pressure switch is being stubborn and I haven't been able to unscrew it by myself. I have a plan that requires two more hands. If that fails I will have to degas and make a line. I am still running r12 so degassing is last option.
I hope the Windstar conversion will bring my temps down below 200° in 110° ambient with ac on.

Soon with a big block trans plant I will be giving up the brass and going Aluminum rad and heater core since the big block will have aluminum manifold and most likely heads. as of this moment I am leaning to the Cold Case direct fit tri flow rad.

I may get some water wetter and see what tomorrow runs though we will only be @ 102° tomorrow.

 

[Wes Harden]

I should have noted 1/2 way on my temp gauge is 203-205° checked with IR gun at t stat housing. Hotter than I like on 77 no computer engine.
Normal 100° or under it run 1/4 temp gauge which @165-175° ac on or off.

 

[Chris Ziemer]

I have been going over my cooling system for a couple years now, AZ summers and the ac push my temps into the low 200's. Today in fact I ran 1/2 gauge all the way home in 110° with the ac blowing sub 60° front and rear. I have a 10" pusher that runs any time the ac clutch is powered. The Pusher fan actually only benefits the ac temp, and not really helpful for engine cooling.
I have 5, 6, and 7 blade fans, AC Delco, US Midwest, Hayden, Duralast, hd and severe duty fan clutches, I have a pile of clutches and a stack of fans. the results always about the same. Also my trans cooler is not through the rad, and I have an external oil cooler.

I am going to do the Windstar fan conversion. Mostly because I have found that I run a trail and the fan clutch fails, one trail one fan clutch, has been this way since I started doing more than fire roads.
I have been procrastinating the Windstar conversion, 2 reasons atm one I want to use a high pressure ac trinary switch to run one of the 2 fans. This will turn the fan only when high side pressure are over a certain psi. I pretty sure I bought one but can't find it atm, and two the existing high pressure switch is being stubborn and I haven't been able to unscrew it by myself. I have a plan that requires two more hands. If that fails I will have to degas and make a line. I am still running r12 so degassing is last option.
I hope the Windstar conversion will bring my temps down below 200° in 110° ambient with ac on.

Soon with a big block trans plant I will be giving up the brass and going Aluminum rad and heater core since the big block will have aluminum manifold and most likely heads. as of this moment I am leaning to the Cold Case direct fit tri flow rad.

I may get some water wetter and see what tomorrow runs though we will only be @ 102° tomorrow.

Thanks Wes, it sounds like you’ve been through it also. I’ve heard you talk about the WindStar conversion, but I’m just not sure I wanna get that custom (meaning I have no idea how to really convert that).

You know, I think all of the big block radiators I’m looking at are two row. And my radiator guy had once told me to go with a two row with 1 inch tubes or bigger and I think I just dismissed him. It seems so counterintuitive to get a two row versus a four row, but I know the air will flow much easier through a two row. Especially with electric fans.

 

[Chris Ziemer]

I should have noted 1/2 way on my temp gauge is 203-205° checked with IR gun at t stat housing. Hotter than I like on 77 no computer engine.
Normal 100° or under it run 1/4 temp gauge which @165-175° ac on or off.

My temp gun also reads a little lower at the thermostat housing. The gauge is running through the block.
Like I said, I’m not particularly mad at 210°, but I’m constantly checking it because it’s already uncomfortable to me and I’m probably over protective of my new motor.
In my mind, I should be able to get a cooling system set up to where it never goes over 190-200. But I’ve lived in fantasyland before.

 

[Wes Harden]

I did this rad 7ish years ago. There are newer cores out there that have more tubes and tube area in 3 and 2 rows then back in the old brass rad days. Even some of the parts store plastic/aluminum cheap stuff will perform very well.

Two years ago I had a brass rad built for dads 72 Ranchero GT 351c 4v. The original FoMoCo 2 row with 60 tubes was replaced with 3 row 119 tube higher fine per inch count brass rad. Internal trans cooler retained. That radiator has issue cooling the engine and running the ac even on the hottest summer days in AZ.
stock fan, clutch and shroud retained.

 

[Wes Harden]

also I have seen some debate about how air flows through a 4 row vs a 2 or 3 row. The cold case I mentioned earlier is a 2 row with 1 1/4" tubes, and 3 sections that flow in a "S" pattern, backwards S.

 

[Chris Ziemer]

You know, this is a lot like when I installed my 6” spring lift. Little did I know I would have to rebuild the entire geometry that GM spent decades perfecting. I got it where it needs to be, but, it was one thing after another.

I’m not sure if this radiator is for people who have more money than brains, but it could be something.

1973 - 1987 Chevy Truck Aluminum Radiator - TALL 20-3/8" *** Dual 11"

1973 – 1987 Chevy Truck Aluminum Radiator – TALL 20-3/8″ – Dual 11″ Fans With Aluminum Shroud – 3000 Total CFM This is our all new aluminum radiator for the 1973 - 1987 Chevy trucks that use the 28-1/4" wide core radiator with an overall height of 20-3/8". Like all of our radiators, it's made...

ecp-radiator.com

 

[Chris Ziemer]

also I have seen some debate about how air flows through a 4 row vs a 2 or 3 row. The cold case I mentioned earlier is a 2 row with 1 1/4" tubes, and 3 sections that flow in a "S" pattern, backwards S.

You must be looking at this radiator, thereabouts. I like it. I don’t know what else a guy could do.

67-76 Chevy GMC Pickup Truck Aluminum Performance Radiator

1967-1976 Chevy/GMC Truck Aluminum Performance Radiator. For use with 4 core mounting brackets and insulators. Or you can modify 3 core version. These COLD-CASE radiators are Tig welded 100 percent aluminum and absolutely beautiful. Don't buy a 3 or 4 row aluminum radiator! It doesn't cool as...

www.coldcaseradiators.com