5 blade vs. 7 blade clutch fan

Posted By: Black_Bee

5 blade vs. 7 blade clutch fan - 06/14/13 06:12 AM

Hey guys!

I've got a 5 blade clutch fan on my Super Bee's 383 and am wondering if swapping to a 7 blade would help cool better.

I have a 3 core aluminum rad and no shroud, and haven't had any cooling issues yet, but haven't really driven the car in really hot weather so I'm not positive that it will stay cool in traffic.

I have the 7 blade sitting on the shelf, so doesn't cost me anything to swap, but don't want to just do it and find out that the 7 blade fans actually cool worse for some reason.

Thanks!

Posted By: RSNOMO

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 06:17 AM

Got a 3-core rad;7-blade fan(with viscous)and a shroud;A/C water pump...

Zero cooling issues...

7-blade is an Air fan...Run it...

Posted By: DAYCLONA

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 06:56 AM

Let's put it another way so as to avoid the usual Moparts banter,...Superbirds when new, where originaly equipped with only 7 blade clutch fans, after the first run of units fell into customers hands, and overheating complaints started coming in, recalls, TSB's, and what cars that were still in production, were retrofitted with fixed 5 blade fans to solve overheating conditions...

Posted By: 62maxwgn

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 12:44 PM

Quote:

Let's put it another way so as to avoid the usual Moparts banter,...Superbirds when new, where originaly equipped with only 7 blade clutch fans, after the first run of units fell into customers hands, and overheating complaints started coming in, recalls, TSB's, and what cars that were still in production, were retrofitted with fixed 5 blade fans to solve overheating conditions...

Mike,you're two blades short !!

Posted By: babarracuda

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 01:55 PM

No fan will work right without a shroud. A 7 blade with a shrould will work great.

Posted By: DAYCLONA

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 02:46 PM

Quote:

Quote:

Let's put it another way so as to avoid the usual Moparts banter,...Superbirds when new, where originaly equipped with only 7 blade clutch fans, after the first run of units fell into customers hands, and overheating complaints started coming in, recalls, TSB's, and what cars that were still in production, were retrofitted with fixed 5 blade fans to solve overheating conditions...

Mike,you're two blades short !!

Ahhh..Most people usually tell me I'm "two oars short"

....fixed is better than clutch anyday of the week

Posted By: Black_Bee

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 03:38 PM

Quote:

Let's put it another way so as to avoid the usual Moparts banter,...Superbirds when new, where originaly equipped with only 7 blade clutch fans, after the first run of units fell into customers hands, and overheating complaints started coming in, recalls, TSB's, and what cars that were still in production, were retrofitted with fixed 5 blade fans to solve overheating conditions...

Thanks for the info!

So 5 blade fixed fan is better than 7 blade clutch... Is 7 blade clutch better than 5 blade clutch? Those 2 clutch fans are my options.

Thanks!

Posted By: dogdays

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 04:35 PM

First of all you don't know if or that you have a problem, so this is all fog.

But, know for certain that any fan will work better with a shroud. So that's where I would start.

After you locate and install a shroud, drive in hot weather and note the results, THEN it may be necessary to ask about fan blades. But until then, it is all useless.

R.

Posted By: Black_Bee

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 06:07 PM

Quote:

First of all you don't know if or that you have a problem, so this is all fog.

But, know for certain that any fan will work better with a shroud. So that's where I would start.

After you locate and install a shroud, drive in hot weather and note the results, THEN it may be necessary to ask about fan blades. But until then, it is all useless.

R.

I'm just trying to maximize cooling with what I already have. I have a 7-blade fan to try, and don't have a shroud to try.

I have been looking for a shroud, but the reproductions or OEM ones are a lot of money, and I have bought several non-stock shrouds from the junk yard that either don't fit, or don't look good installed.

Thanks for the help!

Posted By: therocks

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 06:20 PM

No fan will work right without a shroud?I guess you better go look at most of the Mopars built.Probally over 1/2 or better never had a shroud.My kids OE setup 62 300 413 no shroud.It works better than the hi buck setups that most use.My 65 B body ran for years since I bought it in 69 with no shroud on a BB.Still runs a stock rad but has a shroud as it came with the junk year rad I bought.Neither ever ran over 190 even when I didnt have a shroud.Rocky

Posted By: jcc

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 06:36 PM

So as a vehicle increases speed, a fan begins to really add little to move air thru the radiator. I suspect also a shroud is most effective at a standstill. So when and under what conditions does op have a cooling issue? When we know that we can improve our suggestions

And a superbird has a rather restricted rad opening intentionally, and the car was not originally intended for sitting in traffic.

Posted By: RSNOMO

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 06:47 PM

Quote:

And a superbird has a rather restricted rad opening intentionally, and the car was not originally intended for sitting in traffic.

Bullseye...

OEM A/C cooling configuration seems to work just fine on millions of cars produced...

I've been in bumper to bumper in 95+ degree temps...

I've also ran 90 M.P.H. plus for an 'extended' period of time...

After 20 years, and all different temp extremes, I've NEVER gone beyond 180...

Posted By: 62maxwgn

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 07:23 PM

Quote:

Quote:

And a superbird has a rather restricted rad opening intentionally, and the car was not originally intended for sitting in traffic.

Bullseye...

OEM A/C cooling configuration seems to work just fine on millions of cars produced...

I've been in bumper to bumper in 95+ degree temps...

I've also ran 90 M.P.H. plus for an 'extended' period of time...

After 20 years, and all different temp extremes, I've NEVER gone beyond 180...

Never past 195* here and I have one of those little openings !

Posted By: 68LAR

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 07:57 PM

Quote:

I'm just trying to maximize cooling with what I already have.

After reading most of these posts, it seems you don't know yet what you need.
Here is something to think about.
In traffic, if the car over heats, you need more air movement. (fan/shroud)
At highway speed, if the car overheats, you need more radiator to cool the water.
Fixed fan works best for street cars. Good cooling, but big horsepower drag.
Flex fans work good for street cars also with a little track time. Works better with shroud. Good cooling with less horsepower drag.
Clutch fans with shroud work good for street/strip cars. Good cooling and very little horsepower drag.
With regard to fan blades. A 7 blade will pull more air than a 5 blade.

Posted By: terzmo

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 08:19 PM

Quote:

Quote:

Let's put it another way so as to avoid the usual Moparts banter,...Superbirds when new, where originaly equipped with only 7 blade clutch fans, after the first run of units fell into customers hands, and overheating complaints started coming in, recalls, TSB's, and what cars that were still in production, were retrofitted with fixed 5 blade fans to solve overheating conditions...

Thanks for the info!

So 5 blade fixed fan is better than 7 blade clutch... Is 7 blade clutch better than 5 blade clutch? Those 2 clutch fans are my options.

Thanks!

Had heating issues and a 7 blade,whether on a clutch or not, with a shroud will cool excellent. As of now I have a 6 blade/3 row alum/shroud/160 stat and it runs at 158 down the road in 70 degree weather....165 in traffic...may go to a higher stat but want to see how this works in 80 degree + weather.

Posted By: dogdays

Re: 5 blade vs. 7 blade clutch fan - 06/14/13 09:31 PM

I don't care what Mopar engineers figured out would or would not work and if they saved 59 cents by leaving a shroud off a car, no matter which one it was. That was a decision based on economics.

The simple truth is an axial flow fan works better with a shroud. That's not an automotive thing, it's an aerodynamics engineering thing.

R.

Posted By: feets

Re: 5 blade vs. 7 blade clutch fan - 06/15/13 07:19 PM

Quote:

fixed is better than clutch anyday of the week

Really?

Check with Bill and Ian Harker. Their Charger was running hot on the 2012 Power Tour. When we got to DFW, I had them come over to my place. I snatched the fixed fan off the Charger and installed a heavy duty clutch and 7 blade fan. The car has not overheated since then.
I got to meet up with the guys again this year. They made the full Power Tour (including tons of idling in 90 degree temps) and the cooling system worked like a charm. The car is still running the fan I installed.