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4/07/2020 4:51 PM  #1


Fan shroud opening

Ok, I went digging in the shed and found two fans, one a fixed 7 blade and the other a thermal clutch 6 blade, both 17”.



Both in like new condition, and I’m sure they were both on the car at one point. Do any of you know what the fan opening size is in the 24” radiator fan shroud. I believe that the factory fans were 18”, and I know you only want 1” or less clearance between the tip of the blade and the shroud opening. I  wondering if the 17” is too small?

 

4/07/2020 5:14 PM  #2


Re: Fan shroud opening

kardad wrote:

Ok, I went digging in the shed and found two fans, one a fixed 7 blade and the other a thermal clutch 6 blade, both 17”.



Both in like new condition, and I’m sure they were both on the car at one point. Do any of you know what the fan opening size is in the 24” radiator fan shroud. I believe that the factory fans were 18”, and I know you only want 1” or less clearance between the tip of the blade and the shroud opening. I  wondering if the 17” is too small?

The fan shroud opening measures 18.5". I'm running a 17.25" fan with clutch in mine with this 24" rad mod...

 

4/07/2020 6:03 PM  #3


Re: Fan shroud opening

Hey!!!!!. I just had an idea that kinda relates to your post.
I wonder....... if you could fab up some type of thin "scoop".... BEHIND the fan.......to divert the hot air (removed from the radiator) to blow down /expel in front of the engine and onto the road instead of the hot air being blow onto the engine and trapped underneath the hood?!!  One issue of Mustangs and a lot of pony cars is.......underneath the hood is a very crowded area. So much so that hot engine air is trapped under the hood and in some cases is detrimental to the paint! (so we install under hood insulation to save the paint instead of removing the hot air!)
This my go under my "mental file" right next to the insulated heat shield between the carb and the intake/top of the engine.
6sally6


Get busy Liv'in or get busy Die'n....Host of the 2020 Bash at the Beach/The only Bash that got cancelled  )8
 

4/07/2020 6:13 PM  #4


Re: Fan shroud opening

I have a buddy with a 66 Chevy II that has a supercharged 383 and has always dealt with cooling issues and I know for a while he ran a fan under the hood that discharged into the fender well trying to get rid of under hood heat.

Ok, I hesitate to say this “TKO” he finally got his cooling issue straight once he installed a dual electric fan system with dual temp switches and speed controller.

     Thread Starter
 

4/07/2020 7:03 PM  #5


Re: Fan shroud opening

Factory fan is 17”


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

4/07/2020 7:46 PM  #6


Re: Fan shroud opening

I’m betting if I dig long enough I’m going to find the 24” shroud, I know I had it on there at one time. If I can’t find it, I’ll buy another and then I’m sure yo find it.

     Thread Starter
 

4/07/2020 8:30 PM  #7


Re: Fan shroud opening

A long time ago I read a post somewhere (not here, I think).  It was written by a racer who cut rectangular holes in the outer, rear corners of the hood to allow hot air to leave the engine compartment.  He said it helped keep the car cool.

Who is willing to cut up a perfectly good hood to try?(:-)


Original owner - 351w,T-5, 4whl disks, power R&P
 

4/07/2020 8:35 PM  #8


Re: Fan shroud opening

My original Mach 1 24" shroud opening measures 18-5/8" in height by 18-9/16" in width. Which tells me, and I can see that the bottom edge has warped upwards.


Bob. 69 Mach 1, 393W, SMOD Toploader, Armstrong  steering, factory AC.
 

4/07/2020 10:30 PM  #9


Re: Fan shroud opening

i want to share this Idea about hot air under the hood. the cowl vent is used to pull air into the cars vents and heater. But when using Vintage Air you delete these ports. Now there is still air traveling through this passage. So if you cut rectangular holes or round ones  at the top of the firewall into this passage. Would the force of the hot air under the hood be pushed through these holes and out of the engine compartment by the passing air being pushed in and down the sides of the cowl and exiting under the car?


Slammed Big Blue, ran over the varmints that messed with the Stang. Now all is good in the NW
 

4/08/2020 3:34 AM  #10


Re: Fan shroud opening

Cab4word67 wrote:

i want to share this Idea about hot air under the hood. the cowl vent is used to pull air into the cars vents and heater. But when using Vintage Air you delete these ports. Now there is still air traveling through this passage. So if you cut rectangular holes or round ones  at the top of the firewall into this passage. Would the force of the hot air under the hood be pushed through these holes and out of the engine compartment by the passing air being pushed in and down the sides of the cowl and exiting under the car?

 
There is a huge high pressure area that develops in front of the windshield which forces air down into the cowl vents at speed.  Not sure whether the radiator fan, either manual or electric, would be able to overcome the high pressure in order to vent. 

Another one of those questions that I just don’t see being a problem in the first place. My 66 has that huge engine stuck in there with hardly any air flow room around it and it does not overheat in 100+ Texas temperatures.

Once again, an issue of trying to find a way to cure the symptoms instead of curing the problem, which is an engine that cannot cool internally or a radiator that is not doing the job, or improper air movement through the radiator. (Too small fan, inefficient fan design, underdriven fan due to wrong pulley size, timing issues, etc)

But, the idea of exhausting hot air cannot hurt!   The 68 turn signal style hood is a hood start to put some vents in.  It is alot easier to move hot air UP than it is to force it down.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

4/08/2020 8:24 AM  #11


Re: Fan shroud opening

My engine compartment is more cramped than most and I wanted every advantage to getting rid of hot air from under the hood... so I went with the Shelby hood with the fish gills. There is a massive amount of heat that comes out of them too. 

Another way to help extract heat is to add spacers to the hood hinges to kick the hood up about 1/2" to 3/4" . You can also remove the rubber gasket at the back of the hood too. 


John  -- 67 Mustang Coupe 390 5 speed
 

Board footera


REMEMBER!!! When posting a question about your Mustang or other Ford on this forum, BE SURE to tell us what it is, what year, engine, etc so we have enough information to go on.