fan shroud...how much will it cool?

[MustangMatt1966]

ok so i ordered the deep fan shroud from dallas mustangs today, its 3.5 inces deep and is bigger than the stock one. I know the stock one doesnt do anyhting, but this one should help right? How much cooling will it do?

Thanks,
Matt

 

[Great68]

I installed a stock replacement and it made quite a difference.

 

[mdjay]

Looks like you live where it's hot, and your motor is built up so you probably drive it pretty hard. Although I'm sure it will make a little difference at idle, if you hop on it a lot, she's gonna heat up. Then she's harder to cool down. Especially if you have to stop a lot. The 17" radiators in the 65-66 cars are too small to cool a performance motor in warmer climates. Although I love this body style, this is a constant post on the 65-66 cars. Ford new it, and stepped up to the plate with the 67-68 cars. They accept up to a 24" wide radiator.

 

[MustangMatt1966]

yeah, you guessed it, i live in florida where it is constantly like 95 degrees and everyhting is stop and go. I have added and electric fan and have done pretty much anything to cool the beast down<----trying to avoid buying a new radiator, but the fact is i will probably have to by one soon, cuz the car is starting to really get hot. Plus i do have a tendency to be on the gas a lot thanks for your help guys

 

[Ronstang]

Sadly a deep fan shroud is not necessarily what you need. I read a very good article many years ago about fan/fan shroud technology and it was stated that for optimal efficiency the fan blades should be 50% in the shroud and 50% outside the shroud....this is when looking at the edge of the fan blades. I did an experiment and made a simple fan shroud out of aluminum sheetmetal (stop signs). It was merely a circle that covered the fan blade 50% like stated in the article and about 1/4 inch of space all the way around the fan's circumfrence. I installed this on my Shelby which never had a fan shroud and in the Texas summer it lowered my running temps 15 degrees across the board......I consider this a winner!

 

[DukeGnarley]

i don't know, when i got my fan it came with some instructions that said if it is within a certain distance from the radiator, it would work better without a shroud. so i went without one (my fan is about 1-1.5" from the radiator).

 

[Hack]

Sadly a deep fan shroud is not necessarily what you need. I read a very good article many years ago about fan/fan shroud technology and it was stated that for optimal efficiency the fan blades should be 50% in the shroud and 50% outside the shroud....this is when looking at the edge of the fan blades. I did an experiment and made a simple fan shroud out of aluminum sheetmetal (stop signs). It was merely a circle that covered the fan blade 50% like stated in the article and about 1/4 inch of space all the way around the fan's circumfrence. I installed this on my Shelby which never had a fan shroud and in the Texas summer it lowered my running temps 15 degrees across the board......I consider this a winner!

I read your earlier post about this as well. It makes a lot of sense to me. I believe a shroud that's too deep will reduce cooling just like you say. I would recommend to MustangMatt to install it carefully (avoiding scratching it or anything) and quickly and be prepared to return the shroud if it doesn't fit the way you describe. The car just might run hotter with a deeper shroud.

 

[WORTH]

i don't know, when i got my fan it came with some instructions that said if it is within a certain distance from the radiator, it would work better without a shroud. so i went without one (my fan is about 1-1.5" from the radiator).

This is totally False. A fan blade is designed to blow air, and it does that very well. But it does not suck air from directly in front of it, it gets it's air from the low pressure area around the blade, some comes from the front and some comes from the sides. In your car if it sucks air from the sides it is missing the radiator and just circulating air under the hood. This doesn't help to cool the radiator and adds heat to the engine compartment.

When you install a shrowd the fan can not get air from the sides(under the hood) so it has to pull it threw the radiator. It will definately help, and will never hurt.

 

[jb1dsl]

I live in Florida also and when i put a fan shroud on my 66 it mage a huge diference i the temp. I always had to watch it before but it seems to cool pretty good now

 

[2nd Mustang]

i don't know, when i got my fan it came with some instructions that said if it is within a certain distance from the radiator, it would work better without a shroud. so i went without one (my fan is about 1-1.5" from the radiator).

My 67 also doesn't have a shroud. It's a 302, 4 row radiator, 160 thermostat, stock water pump, flex fan, 8 quart oil pan, headers, 4-speed toploader, no power accessories, etc. Here in SoCal, the hottest it ever got was 190 degrees, even with a radiator leak. It usually runs around 175 degrees, so I don't think a shroud is really required in all instances.

 

[WORTH]

My 67 also doesn't have a shroud. It's a 302, 4 row radiator, 160 thermostat, stock water pump, flex fan, 8 quart oil pan, headers, 4-speed toploader, no power accessories, etc. Here in SoCal, the hottest it ever got was 190 degrees, even with a radiator leak. It usually runs around 175 degrees, so I don't think a shroud is really required in all instances.

It's not a matter of requirement, but if you have a problem it will deffinately help. I live in New England, never gets nasty hot around here, My 70 has a 351W with headers and A/C It's got a 3 row with no shroud and a flex fan, it never heats up. So I obviousy don't need one either, but the people that are having problems will benefit from one.

 

[2nd Mustang]

It's not a matter of requirement, but if you have a problem it will deffinately help. I live in New England, never gets nasty hot around here, My 70 has a 351W with headers and A/C It's got a 3 row with no shroud and a flex fan, it never heats up. So I obviousy don't need one either, but the people that are having problems will benefit from one.

Yes, I agree too. I also had a V6 Pathfinder that had a clutch driven fan with a shroud. The space was so confining that to change belts, it was suggested in the manual to remove the radiator, but I found that just removing the bottom half of the shroud and just leaving the top half of the shroud made it easy to change belts without removing the radiator. The removal of the bottom half didn't affect the temperature at all. I left the top half on just as a matter of safety.

 

[ratio411]

Ronstang beat me to it...
A 'bigger' fan shroud is not going to help... just the 'right' fan shroud.
The shroud should cover the entire finned surface of the radiator to pull air evenly. Then it should cone back to a point where the fan is half in and half out of the shroud. Finally, the fan should be a diameter that has around .5" clearance all the way around the shroud opening. If it is too large or small, it is wrong. If the shroud is larger or smaller than the radiator cooling surface, it is wrong. If the fan is too far in or out of the shroud, it is wrong.
If the shroud is cracked or missing chunks from previous damage, it is wrong because airflow is redirected.
Just some thoughts to ponder.
Good luck
Dave

 

[65and68Stang]

So which is more important, fan depth in/out of the shroud (50-50) or fan distance from radiator? With certain applications, you will have to adjust the fan spacing so it will fall in the correct place on the shroud (depth-wise), but the change may not leave the ideal distance from the radiator. I can see where 1/2" or 1" would make a difference in the shroud spacing, but will moving it away/closer to the radiator have as dramatic of an effect?

Thanks!

Kelton

 

[ratio411]

That is why the shroud is there.
If the fan is positioned properly on the shroud and the shroud to the radiator... relationship between the fan and radiator is non-issue.
Dave

 

[cardude]

I have a deep shroud a 4 core radiator, a flex fan and I always heat up at stops even when the temp is in the mid 70 degrees. I was toying with removing the fan all together ang going strictly electric push pull fans. Has anyone done this with successful results?

 

[65and68Stang]

That is why the shroud is there.
If the fan is positioned properly on the shroud and the shroud to the radiator... relationship between the fan and radiator is non-issue.
Dave

Gotcha...thanks!

Kelton

 

[ratio411]

I have a deep shroud a 4 core radiator, a flex fan and I always heat up at stops even when the temp is in the mid 70 degrees. I was toying with removing the fan all together ang going strictly electric push pull fans. Has anyone done this with successful results?

Very few cars have been made since the 80s with mechanical fans. I'd say that is pretty successful results.
They use automatic switches to turn them on and off.
Usually a switch on the major accessories like A/C, to turn the fan on with the accessories no matter the temps. Then of course, they use a thermostatic switch to turn the fan on/off at preset or adjustable temps.
My 98 Z uses 2 fans... 1 that is on and off with A/C, the other by temp... the factory settings are super high. I installed a 170* thermostatic switch, super cheap from Jegs, and it runs the fans now. The adjustable switches cost about 10 bux more. $30 vs $20.
Even with electrical though, you need to match the fan's shroud fairly well to utilize the whole radiator, or get a fan only and mod your shroud to work.
Just some ideas.
Dave

 

[MustangMatt1966]

Can someone please look in the dallas mustangs catalog, page 107 part # 3073 and tell me if you think this is the right fan for the job, its a 2 row radiator, electric fan on opposite side of radiator and now i will have a fan shroud also, it runs really hot around here in florida....The title of the part says extra cooling package.........i wonder if they lied

 

[mdjay]

cool it

I have a deep shroud a 4 core radiator, a flex fan and I always heat up at stops even when the temp is in the mid 70 degrees. I was toying with removing the fan all together ang going strictly electric push pull fans. Has anyone done this with successful results?

No go on the pusher. If you go electric, use a puller.

Most of the people making comments have 67-69 cars. The issue is less critical. The 65-66 cars have a dinky 17 radiator. MustangMatt you need to throw the 2 row in the garbage can.

There are several people here I'm sure with 65-66 cars that have cut their core supports and installed the 67-68 20" radiators with great success.

We were the first that I'm aware of that just welded in the 67-68 core support and installed the 67-68 24" griffin alum with saddle brackets and use a dual puller flex-a-lite slimline to cool it. The temp gauge doesn't move... We have a rapped out 302 SC with AC. There's no substitue for a bigger radiator!

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