Sn95, No Electric Fan!

[imp]

Some time ago, we went 'round & 'round on an overheat problem where I was pretty chastised (that's OK!) for remarking about my disdain for electric fans. "Why does everybody use them, then?" Well, just because everybody uses some technique doesn't make it invariably superior. One member mentioned he recalled the SN95 being an involved retrofit to a mechanical fan. I mentioned my '94 temp. fluctuating up and down constantly, which brought quite a few suggestions of something amiss. I pointed out that the Owner's Manual states the temp. gauge fluctuating is normal! They must have foreseen..........

Anyway, I bought a Fox fan and clutch, made up the adaptor to mount it on the SN95 water pump, which has a larger pilot and bolt spacing, yanked out the ridiculous "catch bottle" Ford used (almost 2 feet high!), fan, big bracket, CCRM relocated to fender apron by MAF, and moved the Freon hose out of the way by fabricating a bracket.

Here's the adaptor/spacer being made up:

The electric fan and catch bottle:

The big plastic huffer in place:

The new, smaller catch bottle tucked in front of the radiator. These SN95s have absolutely no room to mount anything the size of a half-gallon milk container!

Will I need a shroud? Drove it today to the P.O., 6 mile trip, 108 degrees out, gauge held quite steady at about 1/4 of the distance through the "normal" markings. Left it idling with AC on about 20 minutes after eng. had gotten hot, no change in gauge reading. 'Course, around here it gets over 120 degrees sometimes.....

So, we'll see! imp

 

[Dan02gt]

As much as I would like to install a electric fan on my fox I like the fact that my mechanical fan just works. It's odd that your electric fan wasn't able to keep the car cool. Of course they do turn off and on and that allows the heat to rise and drop.

I would definitely want to add a shroud to it just to be safe. Being that you have the skills to make the mechanical fan work I'm sure you could make a fox shroud work.

 

[Mustang5L5]

I have that same e fan model on my Fox. With a 3-core radiator, I've never had an issue with it. In fact, a lot of times the fan isn't even on, and when it does come on you can literally watch the mech temp gauge drop like a rock.

 

[imp]

As much as I would like to install a electric fan on my fox I like the fact that my mechanical fan just works. It's odd that your electric fan wasn't able to keep the car cool. Of course they do turn off and on and that allows the heat to rise and drop.

I would definitely want to add a shroud to it just to be safe. Being that you have the skills to make the mechanical fan work I'm sure you could make a fox shroud work.

@Dan02gt
It isn't that the electric did not cool the eng.; it did, but not as satisfactorily as I would like. Main reason is the temp. differential involved between turn on and turn off. Say, if they had it turn on & off every 10 seconds or so, more constant temp. control would result, at the cost of over-stressing the fan motor (as well as it's relay).

The clutch fan is a continuously varying thing, it's drive being "infinitely adjustable", so to speak. So, it's effort is constantly being adjusted to maintain almost constant temperature. Unfortunately, it exhibits some "drag" all the time, even when the clutch is nearly coasting; the electric fan is therefore non-parasitic when shut off.

I expect to hear from "nay-sayers", and that's good, because more can be learned about electric fans. imp

 

[imp]

I have that same e fan model on my Fox. With a 3-core radiator, I've never had an issue with it. In fact, a lot of times the fan isn't even on, and when it does come on you can literally watch the mech temp gauge drop like a rock.

@Mustang5L5
Was it retrofitted, or do you have the 4-banger, which I think came with electric fan? imp

 

[Mustang5L5]

@Mustang5L5
Was it retrofitted, or do you have the 4-banger, which I think came with electric fan? imp

I have the exact same model e fan you removed that I took from a 94-95 mustang in the initial post cooling my Fox 5.0 for the last 15 years or so. It's worked very well, although I'm using a custom fan controller to power it. It really olny comes on when I stop in traffic, otherwise when I cruise around it never comes on. I have it set for 195 and usually my car is 185-190 while driving.

 

[imp]

I have the exact same model e fan you removed that I took from a 94-95 mustang in the initial post cooling my Fox 5.0 for the last 15 years or so. It's worked very well, although I'm using a custom fan controller to power it. It really olny comes on when I stop in traffic, otherwise when I cruise around it never comes on. I have it set for 195 and usually my car is 185-190 while driving.

@Mustang5L5
You have a good cooling system. This fan deal brings up another thought. Do you have yours set up to run the fan whenever the A/C is ON? Ford turns on the fan whenever the A/C is energized. One guy stated they start out on LOW speed, if the eng. is not up to temperature.

The question becomes, what about the clutch fan? It senses air temp. coming through the radiator, as it is always drawing a bit of air when the vehicle is not moving, but what about a cold eng. and demand for A/C? The ciondenser coil is getting HOT, but little air is moving through it, thereby adding to the compressor's workload. Actually, the cheaper of the two types of fan clutch rely only on the viscosity change of the fluid within them; it takes much longer for all those outside fins to affect the fluid heatwise, so that kind is not recommended for use with A/C. imp

 

[90sickfox]

The clutch fans are used on all the fox mustang v8s....with AC. I don't think you need to worry about that.

A fan shroud would help pull even more air through the radiator. I've done clutch fan swaps on a bunch of newer cars...and the mid to early 90s jeep Cherokees ( their water pumps accept older model clutch fans ). I've never had anyone come back to me with a running hot issue. They will cause a little horsepower drop.

 

[Mustang5L5]

@Mustang5L5
You have a good cooling system. This fan deal brings up another thought. Do you have yours set up to run the fan whenever the A/C is ON? Ford turns on the fan whenever the A/C is energized. One guy stated they start out on LOW speed, if the eng. is not up to temperature.

The question becomes, what about the clutch fan? It senses air temp. coming through the radiator, as it is always drawing a bit of air when the vehicle is not moving, but what about a cold eng. and demand for A/C? The ciondenser coil is getting HOT, but little air is moving through it, thereby adding to the compressor's workload. Actually, the cheaper of the two types of fan clutch rely only on the viscosity change of the fluid within them; it takes much longer for all those outside fins to affect the fluid heatwise, so that kind is not recommended for use with A/C. imp

Yes, I wired mine to come on with A/C. Flip the system to a/c and the fan comes on max speed regardless of temps.

All foxes weee the viscosity type clutch fan even with a/c. Pretty much the viscous coupling was a shock absorber for high rpm changes. Otherwise it was max air flow all the time. Big horsepower suck, but big cfm.

A shroud will help draw most of the airflow through the radiator, as without one it's possible to draw from the sides and not through it. Perhaps a fox style shroud will help?

My cooling system is in very good condition. I'm running an older brass three core radiator that isn't made today. Other that that, nothing special about it, and I even run underdrives pullies. I can idle in my driveway and let the temp creep to 205-210, and flip the fan on and it will drop like a rock to 185-190 in seconds, even with underdrives.

 

[General karthief]

Imp, I think your over analyzing this, if it works leave it, but at least put a shroud over the top, you don't need shorter fingers.
I'm surprised the fan don't hit the hood.

 

[imp]

The clutch fans are used on all the fox mustang v8s....with AC. I don't think you need to worry about that.

A fan shroud would help pull even more air through the radiator. I've done clutch fan swaps on a bunch of newer cars...and the mid to early 90s jeep Cherokees ( their water pumps accept older model clutch fans ). I've never had anyone come back to me with a running hot issue. They will cause a little horsepower drop.

Curious, were those swaps done to eliminate OEM electric fans? imp

 

[imp]

Imp, I think your over analyzing this, if it works leave it, but at least put a shroud over the top, you don't need shorter fingers.
I'm surprised the fan don't hit the hood.

That was the first consideration while doing the groundwork. With all the crap hung behind the radiator, it was a bit difficult to measure, but a 9" radius upwards from the waterpump centerline looked OK. Sure enough, the Fox fans are 18". It clears the underhood insulation mat by 3/4", which should be adequate until a mount breaks.....imp

 

[90sickfox]

Curious, were those swaps done to eliminate OEM electric fans? imp

Yes....the old Chrysler fan controllers were plagued with issues. It was a cheaper option I offered customers.

 

[mikestang63]

Bottom line- the stock OEM clutch fan or for that matter the police clutch fan pull a ton of air. and will cool down most fox cars up to 500 hp The only reasons to replace them are

• if the fan/clutch are broken
• you install a supercharger or power adder and need the space
• your car is a race car and need every hp you can get

They are relatively cheap, maintenence free for the most part,you don't have to worry about fuses, wiring failing and if you want ( although not recommended) can keep your 2G alternator.
That being said, I've swapped out the mechanical fan on most of my fx body cars for the reasons above, and I like to clean up the engine bay.
My 86 has the stock clutch fan and a-n aftermarket replacement aluminum radiator and with the A/C on in 95 degree heat barely gets to 180-190. I measured the temperature with an infrared temp gun at the thermostat, temp sensor, radiator and other locations. The radiator was around 140-150, the thermostat around 170-180 and the water temp senor 175-190.

Compare that to my 90 vert with the V3 and with the A/C on I can see it creep up to 205 in city traffic. With the A/C off it will stay 180-190. This car has a 2 core aluminum radiator, and dual contour fans. Using the infrared laser gun I saw high of 140-150 at the radiator, a high of 190-195 at the stat and a high of 202 at the temp sending unit. There was about a 10-15 degree higher reading at the temp sensor than the stat on this car that I attribute to the aluminum intake and heads