Clutch Fan

[sideoilerfe]

The Napa part is the same part i have. '67 Cougar and all of the FE trucks use the same TEM 273325 fan clutch. My question is why is the clutch fan out side of the shroud when the stock ( or flex fan) sits right inside the shroud as it should? I installed it and it seems to work but it is noisy. Here are some pics to compare...

[sideoilerfe]

top view...

[1971ford]

Soo anyone want to explain to me what the advantages of a clutch fan are over a normal fan? My '71 racer with 429 has one. My FE's don't.
Also, why do some fans have a totally unbalanced look to them? Like the fins are not equal on each side.

[ToughOldFord]

A manual fan is on constantly whether your engine needs it or not thereby robbing your engine of the power and economy it takes to spin the fan. The clutch fan lets the fan freewheel when it's not needed and kicks in when it reaches a specific temperature.
It's handier than it sounds as a fan is usually only needed when idling and stop and go traffic on hot days.

[1971ford]

Nice... I think I'll get one for my FE, sounds spiffy.

[Dragon]

Actually put a flex fan or electric fan on your racer. the Clutch is engaged when ever hot air is flowing over the clutch from the radiator. Believe me 7 or 5 blade clutch fans will cause more horsepower drag on the engine than a 4 blade fan on a spacer. If the clutch locks up the fan will suck more power than you can imagine. I have worked on many locked up fans at Ford.

[fordman]

mayeb the manufacturer made the clutch fan spindle to short to make it for both vehicles. i would be interested to see what the ford part numebr if any has to say about both the cougar and the trucks.

[Dragon]

If I remember right in 76 the clutch truck fan was in the shroud all but for the last 1-1/2 of the blades and the LTDs were hard to get the clutch fan loose so we dropped the shroud, remove the blades and then the spindle bolts just to get them apart. But we just unbolted the spindle of the fan off the pump on the truck so they had to be different.

The radiator was closer to my engine in my 67 Mustang 390 Factory Super Stock car than in any of my trucks. My friends that had street 390 Mustangs that had clutch fans complained about getting them off. Almost all of my friends went to flex fans

[sideoilerfe]

Thanks for the help everyone. The true test will be in the summer. I still don't like the fan being outside of the shroud but we'll give it a shot. If it gets too hot then I'll take it off and put a flex fan on it. It helped on the hiboy so it'll help with this one too. At least I put the shroud on.

[ForingaMex]

I replaced my stock fan and spacer with a fan with clutch. Bolted straight to the pulley without any spacer. The fan sits about half way in the shroud same as the original fan. I don't have a compressor on my truck but have no clearance issues. I have no idea what vehicle the fan is from other than that it's a Ford. I just saw it laying around at the yard and figured, this should work. Well, it fit perfect. I'll try to get some picks later.
Jake

[DuckRyder]

I am wondering if the shrouds are supposed to be different? I recall someone saying there were about 3 different ones listed for out trucks...

I do believe the fan should be placed in relation to the shroud so that the drive plate is even with (or slightly inside/forward) the edge of the shroud.

My theories include:

• Ford used the same fan clutch and varied the shroud.
• Ford used the different fan clutches and the aftermarket is replacing 2 part numbers with one.
• Fan clutches were only used with a radiator (supercooling?) configuration that moved the radiator back closer to the fan

[fordman]

i like your theory abotu the different fan shroud. my truck has the original fan shroud on it. so i don't knwo if your theroy is right or not. i don't have any way to deny or confirm my shroud part number right now.

[Dragon]

Not sure about how many shrouds there are, my memory is blurred with how often a shroud was in the way of the work we had to do. I do remember a real deep one but I think that was on a later truck. My 71 had a shroud that was only 2-1/2 inches deep with a standard fan. Plain jane models never had shrouds in my experience. Camper Specials, Sport Customs usually did.

As for a spacer I knew a guy that bought an aftermarket spacer about an inch long and something went horribly wrong. The soft spacer got mangled by the fan and loosened the bolts and that fan broke loose and ate the belts and radiator, Alot of Aftermarket stuff is soft grade aluminum. It is easy for Mr Gasket to machine.

[sideoilerfe]

Plain jane models never had shrouds in my experience. Camper Specials, Sport Customs usually did.

The ones without a shroud used a longer spacer to bring the fan closer to the radiator. I have both spacers and when I installed the shroud, I installed the shorter spacer with the stock fan and it is correct. However the clutch fan does not sit inside the shroud.

I am wondering if the shrouds are supposed to be different? I recall someone saying there were about 3 different ones listed for out trucks...

I do believe the fan should be placed in relation to the shroud so that the drive plate is even with (or slightly inside/forward) the edge of the shroud.

My theories include:

* Ford used the same fan clutch and varied the shroud.
* Ford used the different fan clutches and the aftermarket is replacing 2 part numbers with one.
* Fan clutches were only used with a radiator (supercooling?) configuration that moved the radiator back closer to the fan

Could be. I looked at different clutches for 400s and 460s but they are severe duty and are different. I know someone here has access to ford part numbers to compare to aftermarket numbers. I'll more than likely just remove it.

There is a discrepancy of 1/2" between the 4x2 and 4x4 core supports/radiator to engine spacing. I just measured the distance between the rear of the radiator to the rear of the pulley (easiest place for most accurate measurement) and found the 4x2 radiator is 1/2" farther away from the engine. I might just swap fans and see if it works on the hi boy. If not, then it goes on ebay. The 2 fan shrouds are the same.