Fan or water pump?

[HybridFuel]

for all intents and purposes it sounds like you have a fan clutch issue. If it runs hot sitting still but cools fine @ highway speeds you have an airflow problem not a coolant flow problem. If the faster you go the hotter it gets then you have a coolant flow problem. Here a simple test, warm the car up, 220 shoud do it, shut it off and spin the fan by hand, you should feel some resistance, if you give the fan a good price is right spin, it should spin maybe 180 degrees, but not much more, if it spins all the way around a few times then replace it. or ditch the whole setup and go with an electric fan!

 

[gbarber]

Thanks for all the help.
Okay, sounds like I need to work on air flow.
I checked the fan clutch, and it worked fine. I warmed the car up to about 210* and shut it off. I couldn't spin the fan more than about 1/2 a revolution.
My fan blades are about 1/2" from the radiator. The clutch center is closer, about 1/4".
I guess I'll look into replacing the fan with something newer. If I do go with an electric fan, is there a limit on how many amps the fan draws? I have a stock alternator.

 

[dennis112]

Thanks for all the help.
Okay, sounds like I need to work on air flow.
I checked the fan clutch, and it worked fine. I warmed the car up to about 210* and shut it off. I couldn't spin the fan more than about 1/2 a revolution.
My fan blades are about 1/2" from the radiator. The clutch center is closer, about 1/4".
I guess I'll look into replacing the fan with something newer. If I do go with an electric fan, is there a limit on how many amps the fan draws? I have a stock alternator.

Caution: An electric fan is not suitable when you are using a copper 4 core radiator--to much air restriction to overcome due to the dense core.

I can't say I know what your real problem is though because it sounds like you should have an adequate system with the 4 core, fan shroud, and 7 blade fan.

What thermostat are you running?

 

[WORTH]

Thanks for all the help.
Okay, sounds like I need to work on air flow.
I checked the fan clutch, and it worked fine. I warmed the car up to about 210* and shut it off. I couldn't spin the fan more than about 1/2 a revolution.
My fan blades are about 1/2" from the radiator. The clutch center is closer, about 1/4".
I guess I'll look into replacing the fan with something newer. If I do go with an electric fan, is there a limit on how many amps the fan draws? I have a stock alternator.

gbarber gonna give you a little trick, because I still don't trust your fanclutch. take about a 12 inch piece of heater hose, run the car at idle til it's hot, and see if you can stop the fan with the hose. Just rub it slightly to start so it doesn't take the hose out of your hand. aif the clutch is good you sholdn't be able to slow the fan down. if it's bad it will slow and stop if you get enough pressure on the hose.

PS. I am not retarded, I had a radiator shop for 20 years

 

[LMan]

did you get the head gaskets on correctly when you installed the heads?

 

[gbarber]

dennis - I have a 180* thermostat. So you can't run an electric fan with a 4-row radiator?

Worth - I tried as hard as I could to stop that fan. I couldn't stop it. I did replace the fan clutch late last summer with a new one. I noticed yesterday that it seems that most of the air flow from the fan is directed out from the fan not behind the fan. If you put your hand between the distributor and the back of the fan, you feel little air flow from the fan. Almost all of the airflow is felt coming from the edges of the fan. There is plenty of air flow if you place your hand just above and behind the fan and edge of the shroud. Is this normal? The fan pushes all of the air out, not back. It seems like I feel equal air flow across the entire front surface of the radiator(I hope I described that alright)

--I was careful when I installed the head gasket, and I'm sure I positioned them correctly.

 

[dennis112]

dennis - I have a 180* thermostat. So you can't run an electric fan with a 4-row radiator?

An electric fan is probably not good in your situation.

The different forums that I follow pretty much sum it up that the 4-row is too dense to use an electric fan, where as they work excellant with aluminum radiators. The most common aluminum radiators seem to be limited to a max of 2 rows, with each row being 1" or more in width--this allows more direct exposure of the coolant to air movement, less dense finning required.

A flex fan would probably be a better option to try.

As far as the thermostat, I was just curious (and mostly wanted to see if you were running one.)

Was your engine been bored over .30?

 

[gbarber]

It's .040 over.

 

[notny41]

Can you post a picture of your fan/radiator please?

 

[66Runt]

fan's air flow.

Almost all of the airflow is felt coming from the edges of the fan. There is plenty of air flow if you place your hand just above and behind the fan and edge of the shroud. Is this normal? The fan pushes all of the air out, not back. It seems like I feel equal air flow across the entire front surface of the radiator(I hope I described that alright)

Yep, that's correct. This is also why they tell you to make sure your fan blades are at least half way exposed from the shroud.

If you can borrow a good standard fan with spacer, you may find it works better. I am begining to wonder if the diameter of the fan clutch as well as it's close proximity to the radiator is blocking the center of your core from getting air through it.
If you cut a 4" square piece of heavy cardboard, then hold it on different parts of the radiator, see if it "sticks" as well right in the middle as it does towards the edges. If it does not, you have lost that whole area of cooling while at idle. Once you're driving the pressure will force it's way through the center.

Also I like notny41's idea of pictures, if you can.

HTH,

Scott

 

[gbarber]

I do have a fan I can try off of a '77 Granada I used for parts. I think it will fit using its 2 inch spacer. I think you may be on to something with the fan clutch blocking air flow. With the added thickness of the 4 row radiator, there is very little room between the clutch and the radiator surface.


Here are a couple pics.
Please excuse the crudeness of my fan shroud. It only cost $10 in materials, and I wanted to see if worked before I ground down the welds and painted it.

 

[66Runt]

That clutch is huge!!!

I think you are right. That clutch looks to me to be blocking a rather large area of the core. The other thing, is that your fan shroud (which you've done a pretty nice job on btw), is also blocking fins. By the looks I'd guess your blocking close to 40% of the total area at idle, betweeen the two. You really want to maximize every square inch of fin and tube area, at least until you get the over heat under control.
I'd start by pulling off that fan clutch and using a stock (for testing purposes) or the biggest flex fan that will fit. Then work over your shround to open up every square inch of the core.

I think there is a somewhat stock looking shroud available through the aftermarket A/C companies, fairly cheap. I'd look closely to see if they seal the radiator without blocking the core, If so you may want to invest in one, or work at modifying your's to do the same. Looks like you've got the skills to make this work.
Good luck!

Scott

 

[gbarber]

Scott
You're right about the shroud partially blocking fins. After I put the shroud on the first time, I was dreading taking it back off to trim off the excess material. It was a pain to get it installed. I had to mark the shroud after I installed it to make the final trim cuts. I have already fixed that problem.
The fan clutch I was using was a replacement I bought from NPD. I don't know if it differs from an original.
I just installed the other fan I had. It's going to take some serious effort to get the shroud on with this fan, but it should work. I have to put the shroud on after I install the fan because there is no way to get a wrench between the front of the fan and the radiator if the shroud is on. I'll let you know if it works.

 

[gbarber]

Well I drove my car today in the 90* weather with no cooling problems. I put the old fan that I had in, and put on the fan shroud. I even ran the A/C for most of the drive. Now I have a terrible vibration when I drive. Could this be the fan causing the problem? It is an old fan that looks pretty rough. I wanted to see if it fixed the problem before I invested in a new fan.

 

[66Runt]

First off; Congratulations on solving a difficult problem

Then yeah, I've got to think that unless you left the wrench on one of the bolts You've probably got an out of balance fan.

If you've got a piece of pipe that fits snugly (or use tape to build up the diameter) you could stick through the fan, place the pipe on the backs of two kitchen chairs, or something similar, you can balance it yourself. You've got the welding skills to add a washer or whatever else it might need.

Something cheap to try. I'd really opt for a nice Flexi-lite fan. They are so quiet and work really well.

Scott

 

[gbarber]

Is Flex-a-lite the way to go? I'm more than willing top spend the money for a new one. I just didn't want to buy one and have the fan not be the problem.

 

[66Runt]

For your setup, in my opinion yes.

But this is just my own opinion. You may want to post this as a seperate question.

My '66 still has the I6 in it. I just added A/C with a two core stock 6 cylinder radiator. The Flex-a-lite (thanks for the spell check ) made a about 5 degree difference in cooling at idle, versus the fan they give you in the kit. And it is so much quieter, I can hear the points open and close...no kidding!!! My neighbor comes over and says, "...Man, is that your points I hear?" I hadn't even noticed. I was too busy watching all the pressure and temp gauges I had hooked up at the time.

I have run Flex-a-lite fans on other V8 cars, but never for extra cooling (although they never ran any hotter). It was always the performance I was after.

 

[LMan]

I have a 347 with iron heads.....and a alum radiator, no shroud, and a flex fan...plus a oil-to-water heat exchanger. I can run it on the track in 90* weather and cant GET it over 210* On the street, the t-stat wont even open (180). So, the solution is out there.....