Cooling question

[Chris/Mass]

My '69 F250 has an aftermarket aluminum flex fan which is short of the shroud. The engine has always run on the hot side and I assume this is at least part of the problem.I want to go back to factory fan. Was original a clutch fan or not? Engine is a 390 with C6. Thanks

[mrtleavitt]

I've never seen a stock Ford truck from '67-'72 have a fan clutch. From my understanding though, fan clutches are a good idea if you're running a/c on the engine. I have seen stock clutches on FE engines that came in cars. Not saying they did or didn't, just saying I've never seen a stock setup in the truck.

[lee_ford]

I built a 1961 Econoline with a 289 years back and it always ran hot until I put a spacer between the pully and fan. With the fan closer to the radiator the air is not just running around the fan but pulled through the radiator. Plus a jerry rigged shroud helps too. Also try a little "Water Wetter". Got some at AutoZone and it helped a lot on my KW Semi. I had to use two bottles on it but one is all a normal size car needs.

[crewcabed]

I would have to wonder if it always ran hot does that mean you replaced the stock fan with the flex fan. If so it would sound like your fans may not be problem, maybe something more like timing,fuel mixture IE; mixture to lean ,or possibility cavitation in the water pump. If not a spacer or maybe a lower temp thermostat should help. I personally don't like clutch fans ,I prefer a good quality electric fan.

[ToughOldFord]

Factory didn't have a clutch, but they're a good idea. I gained 1/2 mpg in my 390 when I put one in. Had to pull it though when I put my A/C compressor though, the can doesn't clear the compressor with a clutch on.

[lee_ford]

In theory a fan clutch only spins when the radiator gets the clutch hot enough. They do help MPG and HP because they are not trying to move air unless needed, which is most of the time when you are moving down the road.

Since you did say it has always run hot and it does have a shroud and the fan is not INSIDE that shroud, put a spacer on it. The guy who installed the flex fan must have left the spacer off for some reason. The fan should be at least up to the shroud with little or no gap. Slightly inside is best. Two or three inches can make a world of difference. If the flex fan is too big for the shroud hole then trim it or install a stock fan.

If you are going for original then a fan clutch is out. However if the truck is not ALL original (IE: Numbers matching) then a fan clutch would be considered an upgrade and would not take points off in the Classic Truck class in most car shows. Now Concourse Shows where even the factory assembly plant marks count, any upgrade costs you points.

Up to you now. Good luck and keep us posted.