Five Oh

So I recently purchased a 1977 Vette. One of the first upgrades I planned to do was an aluminum radiator and electric fans. I bought a 2 row champion radiator with dual 12" electric fans.

I installed the radiator and fans and ran the relay. Once I tested everything, it was running around 220 and eventually went up to 240 and I cut it off. Turns out one fan quit working (checked the ground and it is getting power to the fan motor). Contacted champion and they suggested a 3 row radiator and will be sending it to me this week. I also noticed after driving around a bit, the fluid was low in the radiator. When I first installed it I filled it up, started the vehicle for a few mins thinking it would circulate some and refilled it up. But after driving it around it was low again.

I never had any issues with the old radiator so I'm curious why this one is giving me trouble. Also I installed the stock fan shroud back on with the electric fans. Should I have left it off or what is everyone's opinion on that? Any suggestions? Should I go through with having champion send me a 3 row radiator and give it a shot??

cooper9811

I would not assume the radiator needs replaced just yet. A 2-row aluminum rad should cool most SBCs pretty well, especially if it's close to stock. A few questions/observations:

Did the electric fans come with a shroud, and what kind of air does each move?

Did you check for leaks around the hoses after the rad was installed? They may not be obvious at first, and may only show up under pressure (engine running). Make sure those connections are all tight and sealed well.

From your post, I am assuming that the new duel fans did not come with a shroud? If that is the case look for a matching shroud. I can't imagine the stock shroud fits very well with 2 fans under it, unless they are relatively small. Most duel fan kits I am aware of come mounted in a shroud.

Any radiator with inadequate air flow will allow the car to run hot. If one of the fans quit, that needs to be taken up with the manufacturer if you are confident your wiring is good. That alone could cause you to overheat, and has nothing to do (directly) with the radiator.

Also check for leaks at the heater core where the hoses go back up by the firewall. I have had leaks develop there out in the past - With a car this old, just moving or messing with the hoses on a 40 year old car can cause things like that to develop.

Hope this helps give you some things to check.

augiedoggy

You have to jack the front of the car up and burp the air out of system... Also I dont see myself how 2 fans will work well mounted inside of a shroud... the idea is the shroud forces the air to be pulled through the rad... Not sure thats happening here.

also make sure the lower rad hose has the metal spring in it to prevent it from being sucked close at higher rpms.

also thais may sound dumb but are you sure your water pump is running correctly?

Vette-kid

I would also make sure that you have all air out of the system (burp the coolant). I had issues with mine until I got that figured out. If you have trapped air, you will have cooling problems. I doubt there is anything wrong with the radiator, rather its likely the coolant or fan set-up.

diehrd

Burppppppppppppppppp.. But also check the CFM of those fans .. If your only moving a small amount of air with them you need better ones.

And I sorta remember having issues with champion fans because combined the air flow was 1200 cfm or something seriously small . I used Spal 1600 cfm per fan on my champion radiator .

MotorHead

Basically when purchasing a new rad and fans you get what you pay for.

Many years ago I bought a Griffin/no name aluminum rad and then purchased dual Flexalite fans. From day one the rad had a hole in it and I paid about as much to fix it as I paid for the rad.

The engine at the time was about 400HP. The fans worked so-so but I got caught in traffic jam and the temps creaped up and up until I had to pull over and wait for the traffic to dissipate.

After that and a 600HP engine later that was very expensive I said screw this I am going to get the best money can buy as I didn't want to overheat my new engine.

I ended up buying a BeCool rad with twin 13in. Spal fans and I can run around on the hottest day on one fan. If stuck in traffic I can switch the second fan on and the temps drop to normal.

It was basically insurance to save my engine but it didn't come cheap. I shelled out over $1600 for piece of mind and not worry about overheating.

The13Bats

Well you problem is you didn't buy a really expensive name brand radiator....
JK...

The 2 row champion has proven to cool even some hopped up engines, in fact more and more members here are saving several hundred and going with champion and are very happy with them.

I do not understand that if one fan is bad that champion wants to send you a 3 row radiator why not replace the bad fan?
However, pretty darn cool of champion to stand behind their stuff like that.
2 row or 3 row,
More radiator is like a gun or condom it's far better to have it and not need it than to need it and not have it.

you do not need both electric fans and stock fan if the electric fans are what I assume they are, generic 12" with the built in shroud around them like this the stock shroud added over them will not help and might hurt, and if they are really low end cheap fans the CFM might be super low, according to fan companies like Derale and Spal you need at least 3000-3500cfm for most stock small blocks.

I know of a cat on here who runs one 16" electric fan and his car runs cool.

At first I too thought you have trapped air but you are loosing fluid, where is it going? find and fix that leak,

I wired my dual fans to both run on low them both run on high this way at idle/slow moving where fans are needed I get more flow through and less wasted radiator.

Five Oh

So after doing some research it appears the fans are 1740 cfm total. I was under the impression that the fans were 1740 each. So I need more cfm right?

Also I think I wasn't allowing the air to purge out before driving it which was making it run low once the air escaped? Sound right? I know it wasn't leaking anywhere on my carport.

Also noticed the car doesn't have the weatherstripping around the radiator and across the top of the radiator support. So air is leaking so to speak around the radiator right?

Here are a few pics of the set up. What do I need to do? Am I better off leaving the electric fans off and using clutch fan and stock shroud??

The13Bats

yes, the fans are not enough cfm...so in the interest of testing it for free remove the electric fans, replace the clutch fan be sure it's spaced correctly in the shroud be sure the shroud is sealed around the radiator, be sure you get the air out of the system as others outlined how to do and test it, likely it will cool just fine....

PS, keep in mind the fans be them electric or clutch or flex are just for idle and slow moving once you are going over about 30 mph the forward movement should allow enough airflow to cool it, try that test also.

Also is your thermostat good?

Five Oh

Thanks! I believe the thermostat is good? Really don't know much about them or how it works? Def don't have much mechanical knowledge but I want to learn!

The champion radiator is already off the car and being shipped back to them to be replaced with a 3 row. I have the stock radiator back on for the time being but haven't had a chance to really drive it around. The hottest it got with the stock was 220. Is that normal or getting too hot? Keep in mind I live in South Louisiana and it's close to 100F every day. Do you suggest buying the weatherstripping to do around the radiator and support?

cooper9811

220 is really not bad. Any hotter and I get concerned, but given the heat where you are, not horrible. I try to shoot for 180-200 range.

Make sure whatever you do with fans, you get a shroud that
1 - covers the rad surface
2 - forces the air directly to (and through) the fans. From your picture, I cannot imagine that using the stock shroud over the electric fans will work well if at all.

On the thermostat - once the car is up to operating temp, feel the upper hose. You can tell if hot water is flowing (it'll be hot, meaning the thermostat has opened at it's preset temperature).

Also - What temp thermostat are you running? That sets your minimum operating temp. My preference is 180, but some folks like a warmer running temp.

'75

Definitely install all the seals around the radiator. You need to keep the air going through it and not around.

Five Oh

Honestly I don't know what temp thermostat I'm running. As far as the shroud do you have a pic or suggestion on what type of shroud you are referring to with the electric fans. So I can still run the clutch fan with aluminum radiator and stock shroud?

I will be ordering the seals today for around the radiator

The13Bats

On the 'stat, it's not expensive or hard to check/swap out,
You should do that so you know, when you take it out it should have the temp stamped on it, if it looks okay you can test it, what I do is stick a pan of water on the stove, place the stat in it, turn on the heat, I have a thermometer in the water and I see what temp the stat opens at, I do that even with new ones so I know they work right.
In most cases I run 180, it gets the car up to temp quicker and in florida I will not see the day it's cold enough to need a stat to stay at high enough temps like folks in cold regions need.

I also could see that a factory temp gauge or sender could be a little off and then it appears hotter or cooler than it really is, 220 is okay if it doesn't creep up at all, if it creeps then something isn't right.

The shroud this type fan has it built around it, when these are used on a radiator the area of the radiator not covered is to a degree wasted because less to very air flow is happening at idle where you need that air flow, I like running dual fans both on low both on high so the area behind the off fan ( on a system with dual fans one on for low both on for high ) isn't mostly wasted at idle.





We have some people use a larger shroud with this type fan and sometimes they run one fan or two but their shroud which in a few cases actually is an aluminum tray for food with fan holes cut in it covers all or most of the radiator, in that now very little to no radiator is wasted, the shroud isn't tight against the radiator but has a little space. but no leaks around it.
My aftermarket dual fans came this way, and the trap doors are in the event it need to pass more air while moving at speeds down the road.

the picture shows a basic shroud for dual fans and a set up like I run,




My fans move 2000cfm each.


the stock shroud is really best only for the stock clutch fan or a flex fan, some people do not dig flex fans but they work likely just as well as a stock fan at idle if the spacing in the shroud is correct which is very important.

Also when people step up to aftermarket larger performance aluminum radiators then in some cases they get by with less fan CFM as the radiator is larger for the application and more forgiving,

You will like the 3 row a lot.

Five Oh

OK I really appreciate the input. So in theory, if I moubted the dual fans on the radiator without the stock shroud I should be good. But would be better to run higher cfm fans? I belive these are puller fans right? Any better to run pusher fans? And do they mount on the inside of the radiator or outside (pusher fans)?

The13Bats

pusher fans mount on the front of the radiator and push air and pullers ( more common ) mount on the rear of the radiator and pull and most agree pulling is better, and yes, if you try the electric fans no need for the stock shroud,

When you wire your fans be sure they are pulling the air not pushing it from the back side of the radiator a lot of people make this mistake and wire backwards and I always double check myself on it.

While your fan cfm seems low it's free to try and see what happens.

Five Oh

Cool, anxious to get the 3 row in as well as the replacement fan and see how it works out. Thanks
guys!

Five Oh

Still waiting on the new radiator to get here. I've decided while I have the radiator out I am going to replace the water pump and thermostat to be safe and know that I don't have issues with those. That being said is there a certain brand to stay away from? Also being in hot temps here in south Louisiana, what thermostat should I go with? 180F?

The13Bats

180 is fine,

I would hit up Ernie Willcox, and ask him what water pump I am safe with if I wanted to go stock iron but if I need one I will likely go aftermarket aluminum, save a little weight and might be made pretty good...personally I would see what edelbrock offers....also a look at the jegs catalog,

Okay now I will get flamed....

Blue Time

I just talked to the Girl at Champion (note there are 2 different champions), I asked if I should buy the double fans- She asked if I had the stock clutch fan with the shroud intact. She said that works the best. I have 3 row on the way for my 69. 4 row required new brackets. I am putting in a 408 sbc, hoping this 3 row will work. Just my 2 cents