[Lew540]

The fans are the Durale thin line they are like 2.5 inches deep. They draw about 15 amps each and I have the Durale controller also. The flat shroud work on the electric there as it pulls through (plus there are 2 I do have the pressure flaps on bottom for higher speeds) yours the fan needs to be more inside the shroud. The blades need to be halfway into the shroud so you need to pull yours out (make a bigger box) and 1-2 inches.

 

[-SS454-]

If you want or need better cooling, then that fan and shroud are not very good. A 15" fan is too small in general, stock is like 19". Being a thin fan it doesn't have enough surface area to move enough air. And fans work when enclosed in a shroud to get proper suction, the fan is just sitting a couple inches outside an circle cut out.

I do not know of a fan/shroud combo that works well with a serpentine system. Hopefully someone has a combo that works.

 

[LaVelle]

Major problem is the shroud followed by the fan.

As stated above, the shroud DOES NOT enclose the fan.
Resulting in the fan not moving very much air through the radiator core itself.
It needs a ring like this, without the inner lip/flange if possible.

Second a fan with more blade area.

vs

Otherwise, the shroud is fine.
The shroud being close is only a problem going down the road without air flaps. (Which you have)

 

[69_CHEV_ELLE]

Here's a DIY shroud. No flaps, but wouldn't be hard to make some cutouts and rivet in a few flaps.

Amazon.com: Aluminum Fan Shroud Kit for 28 Inch Radiator, Engine Driven Fan : Automotive

Buy Aluminum Fan Shroud Kit for 28 Inch Radiator, Engine Driven Fan: Fans - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[mdelgado]

Thanks guys, I'll modify the shroud first and see how it works. I know my 15" fan is small, but it was really intended to just supplement the two 12" electrics. I bought some 2" angle aluminum, so I'll make a loop around the fan to contain it more.
Think making a hoop around the fan is more effective ? or moving the whole shroud out over the fan, so fan is half in/out, creating a bigger box?

 

[Bob Tiley]

Major problem is the shroud followed by the fan.

As stated above, the shroud DOES NOT enclose the fan.
Resulting in the fan not moving very much air through the radiator core itself.
It needs a ring like this, without the inner lip/flange if possible.

View attachment 741274


Otherwise, the shroud is fine.
The shroud being close is only a problem going down the road without air flaps. (Which you have)

That ring is an improvement but the shroud being that close to the radiator will still restrict airflow. Much better to space the entire shroud out 2" and source a fan that is about 1" smaller than the opening. Make sure your motor mounts are good and don't move too much or the fan will hit the shroud.

 

[123pugsy]

Take off the shroud completely and try it. It's restricting the amount of air the pushers are ramming thru.

 

[65cayne]

Thanks Kirk, I hear everything you're saying, makes sense. Maybe I can try to make a fiberglass shroud with more of a cone shape. Given the space it may not be too much of a cone though.

That shroud looks like the universal kit that I viewed recently on Summit. It came with a "barrel" shroud that attaches to the surface and encloses the fan. Yours was never installed.

 

[Kirk's67SS]

Thanks guys, I'll modify the shroud first and see how it works. I know my 15" fan is small, but it was really intended to just supplement the two 12" electrics. I bought some 2" angle aluminum, so I'll make a loop around the fan to contain it more.
Think making a hoop around the fan is more effective ? or moving the whole shroud out over the fan, so fan is half in/out, creating a bigger box?

In my opinion the Pusher Efans are Restricting Air Flow at Speed Please See my # 14 Post
and this Sticky plus Note Rules #ed 2 / 3 / 7
9 Rules for Improving Engine Cooling System Capability...
SO if you are only going to go 30-40 Miles an Hour then you donot even need the Mech Fan

 

[LaVelle]

X2 on removing the pushers.

 

[LaVelle]

That ring is an improvement but the shroud being that close to the radiator will still restrict airflow. Much better to space the entire shroud out 2" and source a fan that is about 1" smaller than the opening. Make sure your motor mounts are good and don't move too much or the fan will hit the shroud.

Agreed, having a deeper shroud would have better airflow going down the road. Tapered is even better, but with the short space in the per say fist gen A-bodies. Options are limited.

 

[123pugsy]

X2 on removing the pushers.

He should, if changing out the POS fan blade that's on there.
Them flex fans are noisy useless things. The one I had, I hung on my wall as art til someone wanted it.

 

[mdelgado]

A lot of good feedback on here. Since no one likes my fan, I'll start there. I ordered up an 18" Derale. And since my shroud will be too small, I'll remove that for now.

 

[mdelgado]

This is pretty typical, I got the fan delivered, opened the box only to realize I had that same one hanging on my wall from a couple years ago.....

I got it installed and it's real tight in there. I'll have to make a custom shroud. But I did take it for a ride and she didn't get hotter than 165. Sounds like a tornado over 2000 rpms, but i guess that's better than sitting on the side of the road waiting for it to cool down. Thanks for the help guys!

 

[-SS454-]

I believe there is something about the Derale fans that make them loud. My Derale fan sounds like a jet engine too, even with a thermal clutch.

 

[mdelgado]

I think that's why I pulled it and went with electric fans. At this point I'll just use what works. I'll try to take a vid sometime of the noise it makes.

 

[Clintsblue66]

Where is your vacuum advance going to the distributor on your carb above the throttle plates or below ? Above will give you a higher running temp, I found this on my 66 Big Block had to purchase a new base plate with a vacuum port below throttle plates it advanced the timing and lowered the temp ! Above vacuum port was used in 1970 and above for emissions raising the temps

 

[64SS427]

My set up on my 64 is much simpler than yours and runs dead nuts at 165, even in 80+ degree temps. I have an iron headed 427, big iron lump. My radiator is an original 1967 small block unit that a local radiator shop upgraded to a 5 row, still copper and brass. I have the appropriate reproduction shroud. My fan is one I got off some GM car in the junkyard 25 years ago. There’s a better GM fan that I think is known as 992? I have a typical parts store Hayden fan clutch and short pump, nothing fancy. My carb runs fairly lean and my timing is 18 initial, 36 total all in by 2500 plus 12 degrees vacuum advance at manifold vacuum.

Devin

 

[mdelgado]

Where is your vacuum advance going to the distributor on your carb above the throttle plates or below ? Above will give you a higher running temp, I found this on my 66 Big Block had to purchase a new base plate with a vacuum port below throttle plates it advanced the timing and lowered the temp ! Above vacuum port was used in 1970 and above for emissions raising the temps

I'm running a throttle body fuel injection with an integrated timing control. So no vac advance.

 

[mdelgado]

My set up on my 64 is much simpler than yours and runs dead nuts at 165, even in 80+ degree temps. I have an iron headed 427, big iron lump. My radiator is an original 1967 small block unit that a local radiator shop upgraded to a 5 row, still copper and brass. I have the appropriate reproduction shroud. My fan is one I got off some GM car in the junkyard 25 years ago. There’s a better GM fan that I think is known as 992? I have a typical parts store Hayden fan clutch and short pump, nothing fancy. My carb runs fairly lean and my timing is 18 initial, 36 total all in by 2500 plus 12 degrees vacuum advance at manifold vacuum.

Devin

The long water pump and serp kit really takes up some real estate.
I'm doing well now. I installed the larger fan and put the 180 t-stat in and she seems to stick right there on 180.