which fan shroud to use? - Chevelle Tech
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post #1 of 19 (permalink) Old Sep 22nd, 19, 11:03 PM Thread Starter
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Mason
 
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Location: San Diego, CA
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which fan shroud to use?

I have a 70 Chevelle with a BBC, alumitech radiator, and twin 11" SPAL fans. I am thinking about going to a mechanical fan setup if I can't solve my cooling issues.

My car was originally a sbc with the 3 bolt top plate, and I want to run the correct shroud for HD AC cars. Do I need to switch to the core support that had a 4 bolt top plate to be able to run this shroud?

I did already remove the portion of the core support that allowed for the bigger radiators

'70 Chevelle Malibu
454 .030+ /Demon 850 12bolt w/Eaton Posi/Richmond 3.42's/Yukon Axles

'69 Toyota FJ40
5.3L Vortec/SM420/3spd xfer case
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post #2 of 19 (permalink) Old Sep 23rd, 19, 12:30 AM
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Greg.
 
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Re: which fan shroud to use?

The Dual 11" SPAL Efans/Shroud is for/fits on a 23.5" x 16" Down Flow Rad for a 66/67 Chevelle like I have in my 67

So how Wide & High is the Hole in the Support Panel now ?

A 70 Chevelle had/uses a Xcross Flow type Rad

No you do not need to get a new Support Panel
but you should have the 4 Bolt Top Plate and you need 4 New Larger Rubber Pads for the bigger XF Rad
Here is the Thread on it done on a 70
https://www.chevelles.com/forums/32-...g-cooling.html

You should get a XF Rad that has a Core Size that matches the New Sized Support Panel Hole
and the Shroud for a Mech Fan Setup that covers/matches the Size of the Core of the XF Rad
GrdUp sells everything you would need
https://www.ss396.com/mm5/merchant.m...5D=&query=Rads

https://www.ss396.com/mm5/merchant.m...ry=Fan+Shrouds

If you want Efans/Shroud here are ones I would consider, if your Rad Core matches their Size

https://www.summitracing.com/int/par...-298/overview/

https://www.jegs.com/i/Flex-A-Lite/400/295/10002/-1

https://www.jegs.com/i/SPAL/063/30102130/10002/-1

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


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post #3 of 19 (permalink) Old Sep 23rd, 19, 12:33 AM
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Greg.
 
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Re: which fan shroud to use?

At the Top of the H & C Forum there are some good Stickys
70SSTHUMPER likes this.

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


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post #4 of 19 (permalink) Old Sep 24th, 19, 10:40 PM Thread Starter
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Mason
 
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Location: San Diego, CA
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Re: which fan shroud to use?

Hi Greg,

Rad was spec'd for a BBC. The center section of the rad is about 30" wide and complete fills the core support even after I removed a good portion that was blocking air flow. My SPAL fans are

 

:

same shroud and everything. I run a 180* T-stat and a high-flow WP and 50/50 coolant. On a hot day if I'm moving, there's no issues I sty at 180* on the dot. But if I hit traffic I can reach as high as 205* on my gauge (reading from the intake) which puts me at 220*-225* in the head which is what has me worried. I tried playing with the fans coming on earlier etc, and that didn't help much.

I was thinking about going mechanical after reading SWHEATON's post about cooling advice 101.

'70 Chevelle Malibu
454 .030+ /Demon 850 12bolt w/Eaton Posi/Richmond 3.42's/Yukon Axles

'69 Toyota FJ40
5.3L Vortec/SM420/3spd xfer case
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post #5 of 19 (permalink) Old Sep 25th, 19, 6:28 PM
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Greg.
 
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Re: which fan shroud to use?

Mason those are the Efans/Shroud I have on my Small 2 Tube Core Rad for a 66/67 SBC or BBC and they Cover the 16" Hi x 24" Wide Core of my Small 2 Tube Core Rad

Here is a Pic of what that Smaller Efans/Shroud looks like on my Smaller 2 Row Core Rad



I would bet yours does not cover the whole Core of your Rad !!
and for that Reason the Efans are not Pulling any Air Flow thru the parts of the Rad Core that are not covered by the Shroud .
And thus the Reason the Engine runs Hotter in Traffic

You need a Bigger Efan/Shroud for the Bigger/Wider Sized of your Xcross Flow Rad

What is the Measurements High x Wide of your Hole in the Support Panel ?

What is the Measurements High x Wide of your Core of the Rad ??

This Efans/Shroud measures 17-1/2'' Hi x 27-1/2'' Wide x 4'' Deep
https://www.summitracing.com/int/par...-298/overview/

This Efans/Shroud measures 17-1/2'' Hi x 27-1/2'' Wide x 4'' Deep
https://www.jegs.com/i/Flex-A-Lite/400/295/10002/-1
https://www.summitracing.com/int/par...-295/overview/

This Efans/Shroud measures 17-5/16'' Hi x 25-13/16'' Wide x 4'' Deep
https://www.jegs.com/i/SPAL/063/30102130/10002/-1

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


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Last edited by Kirk's67SS; Sep 25th, 19 at 6:44 PM.
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post #6 of 19 (permalink) Old Sep 25th, 19, 6:37 PM
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Greg.
 
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Re: which fan shroud to use?

BIG NOTE
A Mech Fan Setup does not work as Well as a Efans/Shroud do in City Traffic

Because the Mech Fan only Turns at the Speed/Rpm of the Engine in Stop/Go/Idle Traffic

While Efans Turn at their Max RPM all the Time/while in Stop/Go/Idle Traffic
and most of the Time do not even need to be ON while Driving down the Hwy

Also do you have any Pics of the Grill side and Engine side of your Efans/Shroud & Rad Setup ?

Plus how many Rows of Tubes in your Current Rad ??

Plus is there a Trans Cooler or A/C Condenser in Front of the Rad ???

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


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post #7 of 19 (permalink) Old Sep 26th, 19, 1:00 AM Thread Starter
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Mason
 
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Location: San Diego, CA
Posts: 488
Hi Greg

You are correct, my efan shroud doesn't cover the entire core. This picture from Dewitt's radiator is exactly what my setup looks like on the engine side. I'll get all those pics and dimensions for you tomorrow.

When I did all this work (10years ago) I lived in Seattle, and it worked great. Now that I'm in San Diego it's been an issue. I'm eager to see what we can come up with to try.

Pics and dimensions to follow
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'70 Chevelle Malibu
454 .030+ /Demon 850 12bolt w/Eaton Posi/Richmond 3.42's/Yukon Axles

'69 Toyota FJ40
5.3L Vortec/SM420/3spd xfer case
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post #8 of 19 (permalink) Old Sep 26th, 19, 9:29 PM Thread Starter
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Mason
 
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Re: which fan shroud to use?

Hi Greg,

Here's what I have:

Radiator Core Dimensions : H: 17 1/2 W: 28 1/4

Core Support Opening Width: 27 1/2"

Radiator is a 4 core aluminum.

Attached are the pictures of the portion of the core support that my buddy and I removed when prepping for the radiator. Last picture shows the engine side of the radiator, that gap between the shroud and the edge of the radiator core is the same on both sides, it's about 2 1/2 inches wide on both sides. That Transmission cooler is still there.
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'70 Chevelle Malibu
454 .030+ /Demon 850 12bolt w/Eaton Posi/Richmond 3.42's/Yukon Axles

'69 Toyota FJ40
5.3L Vortec/SM420/3spd xfer case
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post #9 of 19 (permalink) Old Sep 27th, 19, 8:44 AM
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Lew
 
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Re: which fan shroud to use?

I think Spal also makes a dual 12 inch fan (similar format) that is about 10%-15% more powerful than the 11s. It should fit on a wide 70 Chevelle radiator.
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post #10 of 19 (permalink) Old Sep 27th, 19, 9:45 AM Thread Starter
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Mason
 
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Quote:
Originally Posted by Lew540 View Post
I think Spal also makes a dual 12 inch fan (similar format) that is about 10%-15% more powerful than the 11s. It should fit on a wide 70 Chevelle radiator.
I've been looking at that one, it's definitely a big jump in cfm, but it also doesn't cover my whole rad. The shroud for those fans is only 25" wide and my core is 28". I think derale has a fan/shroud combo that fits, I have a question in to them on who the manufacturer of the fans is.

'70 Chevelle Malibu
454 .030+ /Demon 850 12bolt w/Eaton Posi/Richmond 3.42's/Yukon Axles

'69 Toyota FJ40
5.3L Vortec/SM420/3spd xfer case
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post #11 of 19 (permalink) Old Sep 27th, 19, 2:44 PM
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Greg.
 
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Re: which fan shroud to use?

Quote:
Originally Posted by bad.samaritan View Post
Hi Greg,
Here's what I have:
Radiator Core Dimensions : H: 17 1/2 W: 28 1/4
Core Support Opening Width: 27 1/2"
Radiator is a 4 core aluminum.

Attached are the pictures of the portion of the core support that my buddy and I removed when prepping for the radiator. Last picture shows the engine side of the radiator, that gap between the shroud and the edge of the radiator core is the same on both sides, it's about 2 1/2 inches wide on both sides. That Transmission cooler is still there.
First of all the 4 Row Tubed Core Rad which has small Tubes(3/8") is more of a Restriction/impediment to Air Flow
and then the added Trans Cooler in Front of that

Efans work better/with less Restriction/impediment for Pulling Air thru 2 Tubed Row Core Rads with bigger Tubes(1.25")

If you want to stay with Efans/Shroud and there is Space/Room(4"+) between Rad and Engine
I would think one of the below would work to cover your Rad's Core;
Cone Shaped / Rubber Hwy Flaps / Brackets for Mounting / Two 13.5" Fans 4600 CFM / Fits models with 28 in. wide core only

This Efans/Shroud measures 17-1/2'' Hi x 27-1/2'' Wide x 4'' Deep
https://www.summitracing.com/int/par...-298/overview/

This Efans/Shroud measures 17-1/2'' Hi x 27-1/2'' Wide x 4'' Deep
https://www.jegs.com/i/Flex-A-Lite/400/295/10002/-1
https://www.summitracing.com/int/par...-295/overview/

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


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post #12 of 19 (permalink) Old Sep 27th, 19, 10:28 PM Thread Starter
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Mason
 
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Re: which fan shroud to use?

Quote:
Originally Posted by Kirk's67SS View Post
First of all the 4 Row Tubed Core Rad which has small Tubes(3/8") is more of a Restriction/impediment to Air Flow
and then the added Trans Cooler in Front of that

Efans work better/with less Restriction/impediment for Pulling Air thru 2 Tubed Row Core Rads with bigger Tubes(1.25")

If you want to stay with Efans/Shroud and there is Space/Room(4"+) between Rad and Engine
I would think one of the below would work to cover your Rad's Core;
Cone Shaped / Rubber Hwy Flaps / Brackets for Mounting / Two 13.5" Fans 4600 CFM / Fits models with 28 in. wide core only

This Efans/Shroud measures 17-1/2'' Hi x 27-1/2'' Wide x 4'' Deep
https://www.summitracing.com/int/par...-298/overview/

This Efans/Shroud measures 17-1/2'' Hi x 27-1/2'' Wide x 4'' Deep
https://www.jegs.com/i/Flex-A-Lite/400/295/10002/-1
https://www.summitracing.com/int/par...-295/overview/
Is it not possible to cool a 4 core with a efan as a primary? Or is it just not optimal? Looking at some of these fan kits I am not far off from a champion 2 core rad with efans and a shroud. If I'm going to gut my cooling system, I'd like to nail it this time and only spend the money once. I saw a disclaimer today on Flex-a-lites web page about not using efans as a primary on a 4 core rad.

I think at a minimum my trans cooler needs to be re-done and moved out of the way. I am thinking about switching to a smaller cylindrical style that I can mount elsewhere. that should help out quite a bit.

'70 Chevelle Malibu
454 .030+ /Demon 850 12bolt w/Eaton Posi/Richmond 3.42's/Yukon Axles

'69 Toyota FJ40
5.3L Vortec/SM420/3spd xfer case
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post #13 of 19 (permalink) Old Sep 28th, 19, 1:49 PM
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Greg.
 
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Re: which fan shroud to use?

Moving the Trans Cooler from in front of a/the Rad is a good idea

However there are various Posts in Threads on here that will tell you that Efans work the best
when the Alum Rad only has 2 Rows of Big Tubes(1.25")
and there has been some Rad Companies that say the same thing plus various Videos/Experts on You Tube/Online etc

I have a Smaller 2 Row 1.25" Tubed Core Alum DF Rad in my 67 Car with a SPAL Dual 11" Efan/Shroud with Rubber Flaps
and a Trans Cooler in Front of the Rad located 3" to 4" away from and Down Low
and my Engine runs 170*-180* on the Hwy with either 1 or NO Efans on
and it runs 180* in the City/stop&go Traffic with 2 Efans on
plus Back to Back WOT Runs down the 1/4 Mile Track
in Cool 80* Weather or in Hot 95* Weather

At my last Track Day I had to Heat my Engine up to 160*/170* before Launching on a Run
since it was a Cool under 75* Day




67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


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post #14 of 19 (permalink) Old Sep 28th, 19, 2:03 PM
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Greg.
 
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Re: which fan shroud to use?

Mason I am not saying that putting one of my suggested Efans/Shrouds will not some what lower your Engine running Temps
to the 180* that it ideally should be running at on the Hwy and in the City

Your spec'd Rad was likely for a Big Mech Fan with a Shroud that covers the whole Core of the Rad
so if you want to go that Route by all means do

67 Chevelle Malibu SS Cdn
Born 283 / PG / A51
468/TH400 2,500 stall/ S60 3.70 Gs
Prev Best on M/T ET S/S #3454 street Tires/Dress 2018/05/20
60' = 1.664
1/8 = 7.532 et / 91 mph
1/4 = 11.814 et / 115 mph
NEW Best with 3,500+ Stall TC 2019/09/08
60' = 1.547
1/8 = 7.311 et / 91.76 mph
1/4 = 11.595 et / 114.28 mph


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Kirk's67SS is offline  
post #15 of 19 (permalink) Old Sep 29th, 19, 6:52 PM Thread Starter
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Mason
 
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Location: San Diego, CA
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Re: which fan shroud to use?

Quote:
Originally Posted by Kirk's67SS View Post
Mason I am not saying that putting one of my suggested Efans/Shrouds will not some what lower your Engine running Temps
to the 180* that it ideally should be running at on the Hwy and in the City

Your spec'd Rad was likely for a Big Mech Fan with a Shroud that covers the whole Core of the Rad
so if you want to go that Route by all means do
No biggie, I am taking all this in, and learning as I go. I just want to make sure I am as informed as I can be before I start throwing money at something. Your input is definitely appreciated.

I'm also at a point where I could go either way and re-use some of my existing parts, so I am trying to factor that in as well. If I go efans I already have decent fans and a controller so it would be just swapping in a new Rad. But so far to get a 2 core with 1.25" tubes I'm looking at 700-800 bucks (only found Griffith and Dewitts that sell them so far). If I go mech, the rad stays, and I just buy a shroud and a fan/clutch and I may be in business.

Until moving to San Diego I loved my SPAL setup, and even with the huge difference in weather down here, they've still done pretty well. I think to start I'll move that trans cooler and see if that helps at all then go from there. I'll reply here as I go. Thanks for all the help--Mason
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'70 Chevelle Malibu
454 .030+ /Demon 850 12bolt w/Eaton Posi/Richmond 3.42's/Yukon Axles

'69 Toyota FJ40
5.3L Vortec/SM420/3spd xfer case
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