Need advice from the Bullnose Braintrust.

[Cbarnes]

First off, new parts aren’t always working parts. I’ve had brand new parts that were defective plenty of times. Test your fan clutch. Make sure you’re getting more resistance when it’s hot.

Second, I agree with Gary on the electric fans. You shouldn’t need them if everything is working correctly. Have you verified that you have the correct shroud and the correct fan for the shroud? Is the fan properly spaced in relation to the shroud? If you want to know what they should be, you are on the right website. If you think airflow is the culprit that is where I would start.

Have you bled your radiator to ensure there is no air trapped in the block? Have you checked pressure in the coolant return line by hand? Are the heater hoses getting hot? Have you popped the cap on your radiator and confirmed that water is coming in?

You said it’s getting “warmer than you like”. What temperature does it reach?

I’m definitely not an expert but I’m hoping that If I throw out areas to check and you come back with something noteworthy it might stimulate some discussion on causes.

Also I have a Champion radiator. It is a 3 row and is the “stock replacement” for a 351W. I have it cooling my high compression 460 without a problem. I have a Derale fan and a HD fan clutch (although I don’t necessarily recommend that) and the stock shroud for the 460 in an F series. My coolant runs at 190 (I have a 185 thermostat) and my oil runs at 225 in the summer in Georgia. I don’t see any reason that a 3 row Champion won’t work well for you.

I went out and checked the fan clutch before starting the truck. It had some serious resistance. I would try to spin it, and it would only turn 1/4 to 1/2 a revolution. Pulled the radiator cap and started the truck. Once the thermostat opened water was flowing in the radiator. Checked the heater hoses, both were hot. After a bit the fan clutch relaxed and slowed the fan down. Once the temp got up, the clutch fully engaged and was turning the fan faster. Checked the tack, it was setting on 800 rpm. Fan wasn’t making as much noise as it was on the initial startup, but it was running about 1500 rpm on startup. Will be putting in a mechanical water temp gauge tomorrow. Will also be looking for an aluminum radiator. Or maybe I need to pull it out and take it to a radiator shop to have it cleaned. Flush the engine while it is out, and put all new coolant in.

[Littlebeefy]

NPD sells the Cold Case radiators. I have not tried them but I generally trust NPD. Maybe someone else has. It says it is 2 row but cools better than 3 or 4 row:

https://www.coldcaseradiators.com/product/80-84-ford-broncof-series-truck-radiator

If I go with an aluminum radiator to replace my OE copper one I will be gonig with the Cold Case. The biggest selling point for me is the OE appearance which I can shoot some radiator black on from eastwood and make it look OE.

The other thing is with aluminum it was found fewer tubes that are wider actually cool better than more tubes that are narrow. Something to do with the turbulence created by the gaps between the tubes that can hinder airflow.

Summit explains it a bit better than I can this is what they say below.

Tube Size

The tube size listed is the width of the tube. Wider tubes have more surface area. This means they can dissipate more heat.

How does this affect performance?

In the old days, with copper/brass radiators, more rows meant more cooling. However, it also made the radiator thicker. This adds air restriction, making it less efficient. It is also harder on the fan. For mechanical fans, this means more parasitic power loss.

More rows also means the rear tubes are less effective than the front ones. As air flows through the core, it picks up heat. By the time it gets to the back row, it is warmer than when it started. This means less heat can be removed from the rear tubes. As more rows are added, this becomes a bigger issue.

Aluminum radiators have helped to solve these problems. Because aluminum is stronger, the tubes can be wider. This means more contact area without significantly increasing the thickness of the radiator.

Its why I wouldnt sweat running a 2 row aluminum radiator like Cold Case`s over the OE replacement copper radiator that has 3 rows. It will just be an upgrade in cooling capacity. For me how ever I am weighing costs. New radiator or just pay to have my old copper one cut open and cleaned out for my new engine.

I'm a proponent of airflow being the issue and not coolant flow for the exact reason provided. When I had a fan clutch issue on my (not a bullnose), I had the exact same problems with overheating in traffic but not when moving at a clip.

The fan clutch looks new, you say? Is it possible that it is the wrong fan clutch? Those clutches have lots of different lengths and I would be highly suspicious of the part selection by the PO. The wrong length of clutch would give the same symptoms as a lazy clutch.

According to this page you don't need a spacer so it's just a matter of confirming that you have the right clutch and 5 blade 20.5" fan: https://www.garysgaragemahal.com/cooling-fan-s--illustrations.html

Also, verify your fan shroud. I know that you can't get the 84 460 fan shroud new because I tried last year and I don't think anyone makes it (who knows though). If it is NLA, and the PO was in a pinch, he/she might have put a different one on. If it has a replacement fan clutch than you know the fan and shroud have both been removed at some point so there is no guarantee the originals went back on.

 

[Cbarnes]

I'm a proponent of airflow being the issue and not coolant flow for the exact reason provided. When I had a fan clutch issue on my (not a bullnose), I had the exact same problems with overheating in traffic but not when moving at a clip.

The fan clutch looks new, you say? Is it possible that it is the wrong fan clutch? Those clutches have lots of different lengths and I would be highly suspicious of the part selection by the PO. The wrong length of clutch would give the same symptoms as a lazy clutch.

According to this page you don't need a spacer so it's just a matter of confirming that you have the right clutch and 5 blade 20.5" fan: https://www.garysgaragemahal.com/cooling-fan-s--illustrations.html

Also, verify your fan shroud. I know that you can't get the 84 460 fan shroud new because I tried last year and I don't think anyone makes it (who knows though). If it is NLA, and the PO was in a pinch, he/she might have put a different one on. If it has a replacement fan clutch than you know the fan and shroud have both been removed at some point so there is no guarantee the originals went back on.

Here are a couple of pics. Can someone tell me where on the shroud the p/n is?

[Littlebeefy]

Here are a couple of pics. Can someone tell me where on the shroud the p/n is?

I believe it is on the broad flat portion that faces the engine but I'm only about 80% sure on that.

[Gary Lewis]

Here are a couple of pics. Can someone tell me where on the shroud the p/n is?

There hasn't been a part number on any Ford part since 1966. In their infinite wisdom they decided to put ID #'s, aka Engineering #'s, on the parts but list the actual Part # in the Master Parts Catalog.

I have cross-reference books and can usually come up with the part # that way, but not always.

Anyway, I don't know where the #'s are on a shroud, but I have a shroud or two that isn't installed and tomorrow I'll see where the #'s are. That's not to say yours will be in the same place, but they usually are.

But at first blush your fan doesn't look like it fills the shroud out very well. I think you should measure your fan and the shroud's opening and let us know what you find.

[Gary Lewis]

There hasn't been a part number on any Ford part since 1966. In their infinite wisdom they decided to put ID #'s, aka Engineering #'s, on the parts but list the actual Part # in the Master Parts Catalog.

I have cross-reference books and can usually come up with the part # that way, but not always.

Anyway, I don't know where the #'s are on a shroud, but I have a shroud or two that isn't installed and tomorrow I'll see where the #'s are. That's not to say yours will be in the same place, but they usually are.

But at first blush your fan doesn't look like it fills the shroud out very well. I think you should measure your fan and the shroud's opening and let us know what you find.

This is the info on 460 fans. There were only two and they were both 20 1/2" in diameter.

[Gary Lewis]

This is the info on 460 fans. There were only two and they were both 20 1/2" in diameter.

By the way, the #'s in the last column of the snippet above are the ID #'s that you should find on the fan. This is just one of the few places in the MPC where they helped us by supplying the ID #. Normally they don't bother.

[Littlebeefy]

This is the info on 460 fans. There were only two and they were both 20 1/2" in diameter.

Can't be sure from a picture, but that does look like the correct clutch based on shape and length.

Gary's right: measure your shroud opening. Measure the difference between edge of the fan and the shroud too to get a rough idea of your fan size. Basically any clutch style fan would fit there so who knows.

[Cbarnes]

Can't be sure from a picture, but that does look like the correct clutch based on shape and length.

Gary's right: measure your shroud opening. Measure the difference between edge of the fan and the shroud too to get a rough idea of your fan size. Basically any clutch style fan would fit there so who knows.

Best as I can measure without taking them off. Fan = 19 3/4”. Shroud opening 23 1/2”.

 

[Gary Lewis]

Best as I can measure without taking them off. Fan = 19 3/4”. Shroud opening 23 1/2”.

I think you have the wrong fan, and maybe the wrong shroud but I'll measure Big Blue's shroud tomorrow to see how big its opening is.

On the fan, it isn't just the diameter but also the pitch of the blades that is different. I think the fans for the 460's and diesels have very aggressive pitches and are intended to move a lot of air. And I don't think the ones for the smaller engines are as aggressive.

If it was me I'd pull the fan and find the # on it. And while you are at it I'd check the # on the clutch.