Thin to Thick Radiator Fan Depth

[Tiggie]

Completed a single row to double row (three row equivalent so they say) radiator conversion today.

Have some concerns about fan depth. The shroud now swallows the whole fan.



I believe they are said to work best when about half the fan protrudes from the shroud. Anyone else experience this problem, and if so, did it cause any trouble?

Would also note the shroud didn't fit the radiator all that well - the radiator tube and fin area is wider as you can see in the bottom right of the picture above.

Having once owned a factory three row car, I know the shroud is different. I didn't realize how much. For reference, this is a Reach 42-552 radiator in a 1988.

[gadget73]

so several things here. This is all of the possible fan options for 80-89



Here are the clutch options




Radiator options


and the shroud options



Looks like only 2 different shrouds, police vs non-police after 86, and everything from 80-85 and the 351 police cars from 86+ used the same shroud. Whole heck of a lot of options for clutch, fan, and radiator though.

How all that pieces together I don't know. My car has had a police car radiator in it for a long time with a 1990 Towncar shroud. It never had heat problems, but the back of the blades are pretty close to even with the back of the shroud. Whether thats losing some efficiency I don't honestly know, possibly is, but the underdrive pulley is making it worse too. Still doesn't seem to actually care.

[Tiggie]

Thanks for the research! Good to know your car didn't mind the fan being flush with the shroud.

The other car I referenced above was an 82 with the tow package. I compared the fans and clutches side by side and they were dimensionally identical to an 87 single row standard cooling car I also had at the time. I remember the shroud being different. The most noticeable difference between the two was the single row had an extension at the top that protruded farther towards the engine. That is all I noticed at the time and I didn't take any measurements, or even notice if maybe the three row radiator fan sat up in the shroud farther originally.

I did have cooling issues at idle from the three row car as well as the single row. Both times, a fan clutch fixed the issue.

[Arquemann]

I've mostly heard that a mechanical fan is best when it sits about halfway out of the shroud, but atleast not all the way in.

Anyways, I went to look at mine.
My radiator core is about 2.25" thick. I suppose that'd be a 3-core? Rad looks original, but I can't see a Ford stamp or PN on it. Copper fins and tanks but the top strap is alu.
The shroud says D9AE-8146-AA, not as wide as the radiator core either, but definitely covers better than yours. I wonder if your aftermarket rad has a wider core. Also has the little extension on the top like you mentioned.

Fan fits nicely:

[gadget73]

maybe a little more food for thought. Just did a radiator in the Mark VII, obviously not the same car but same era and whatnot. OE is a 2 core brass radiator. I replaced it with another OE 2 core brass, so identical dimensions. Stock fan shroud, stock replacement fan, stock replacement fan clutch, stock replacement water pump so it all should be at the same relative position as it left the factory in.

Rear edge of the fan is even with the rear edge of the fan shroud for most of the way around. At the top it has a 'brow" sticking back toward the engine so the fan is in from the back edge by about an inch. There is a spot at the bottom where the shroud is recessed, so the back edge of the fan blade sticks out past the shroud by about an inch. Normally those don't have cooling problems either, though I was replacing a 35 year old radiator because it decided it wasn't going to play anymore. Like a genius its now running a 38 year old radiator that is now in it's third vehicle. I'm sure its fine.

[Tiggie]

Rear edge of the fan is even with the rear edge of the fan shroud for most of the way around. At the top it has a 'brow" sticking back toward the engine so the fan is in from the back edge by about an inch. There is a spot at the bottom where the shroud is recessed, so the back edge of the fan blade sticks out past the shroud by about an inch. Normally those don't have cooling problems either, though I was replacing a 35 year old radiator because it decided it wasn't going to play anymore. Like a genius it's now running a 38 year old radiator that is now in it's third vehicle. I'm sure it's fine.

Thanks for the info. That does help my mind rest easier.

I'm sure the 38 year old radiator is fine. At least for now! It could easily outlast a new one.

Still waiting on the quick connect fitting for the transmission cooler lines. Store ordered a part but it's threaded on both ends and not a quick disconnect style. Found the correct one. Hopefully this job will be done after that is fixed.

[gadget73]

sourcing those things is a pain. I usually keep a couple on hand just in case. The Conti and the Towncar use them, the Mark VII uses flare fittings.

You can rebuild those things if you're really in a bind but its sort of annoying. The plastic duckbill thing will pop out, then you have to dig out the O ring down inside. Clean it all up real well, put in a new O ring and the duckbill thing and you're good to go.

[Kodachrome Wolf]

I've got the same radiator in my '79, but I needed to replace the original unit since it was rather clogged up. I think the original unit was a two-core depth unit... it was at least notably thicker than the unit in the '87 which is a single core.

On the '79, I re-used the existing fan shroud, but did swap from the factory flex fan setup to a clutch fan setup from a later Box. The car also wound up with a cast iron water pump when the replacement aluminum unit started leaking after its swap to the replacement engine.



I wouldn't say the fan is exactly halfway from around the shroud, but regardless the car does run at a normal temperature ~195°F.

[Tiggie]

That is a chunky fan shroud! At least it looks bigger.

Haven't driven the car much but I am not losing sleep over the radiator now. Had it on hand, so might as well try to use it.