#1  
Old 05-14-2020, 09:26 PM
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2nd67GTO 2nd67GTO is offline
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Default Minimum distance required? Fan, clutch and shroud.

So I’m tired of fighting warm cruise temps. Brand new build, 67 GTO, 467 stroker, Kauffman D-ports, Edelbrock water pump clearanced to approx .060 thou, March Style Track serpentine pulley set-up. Cold Case 1 1/4” dual tube rad, dual 12” Spal fans controlled by the FAST EFI ECU. 160 deg thermostat and Vintage Air. Runs 170 all day around town (haven’t Driven or ran AC on a Really hot 95+ day). Hit the freeway, 70 mph at 3000 rpm and she climbs to 195 in about 10 minutes. I realize those temps are fine, but ambient has been in low 70s. I can only imagine where the temps would go on a 90+ degree day.

After reading the multiple posts regarding lack of airflow with the CC shroud, I’m contemplating going to manual fan, clutch and shroud.

Problem is clearance Clarence! I only have 4” from the radiator core to the face of the water pump. Is this enough room for the clutch set-up and still maintain the half in, half out of the shroud for the fan? If not, what are my options?

Thanks for any advice or suggestions.
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Old 05-14-2020, 11:02 PM
Murf Murf is offline
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Is there some reason you would have less room than a stock car? Motor & radiator are in their stock location?
I have a 65 with aluminum radiator & run a clutch fan & shroud. I can measure it for you tomorrow if it will help.

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  #3  
Old 05-15-2020, 12:39 AM
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Quote:
Originally Posted by Murf View Post
Is there some reason you would have less room than a stock car? Motor & radiator are in their stock location?
I have a 65 with aluminum radiator & run a clutch fan & shroud. I can measure it for you tomorrow if it will help.

Murf


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Radiator is in stock location. The March serpentine system appears to move everything forward.

Knowing the stock distance would be helpful.

Thanks

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Old 05-15-2020, 01:37 AM
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How well is the radiator sealed in the core support, ie. do you have all those little rubber flaps blocking the air from going around the radiator instead of thru it.

You issue of heating on the freeway is indicative of not enough air going thru.

  #5  
Old 05-15-2020, 04:26 AM
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Originally Posted by Scarebird View Post
How well is the radiator sealed in the core support, ie. do you have all those little rubber flaps blocking the air from going around the radiator instead of thru it.

You issue of heating on the freeway is indicative of not enough air going thru.
I’ve installed the complete AC rubber flap kit. The rad is sealed to the core support.

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Old 05-15-2020, 05:34 AM
Geoff Geoff is offline
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If it is getting hot above 70 mph, unlikely to be clutch/fan related. More pump speed needed [ smaller pump pulley ]. Pump should be overdriven 10-30%.

See:

www.stewartcomponents.com

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Old 05-15-2020, 07:40 AM
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Quote:
Originally Posted by 2nd67GTO View Post
Radiator is in stock location. The March serpentine system appears to move everything forward.



Knowing the stock distance would be helpful.



Thanks


The clutch fan is 3 1/4 inch as best as I can measure. My aluminum radiator is 5 1/4 inch from face of water pump pulley. I am surprised that system would eat up an inch but IDK. Mine is a 65 tho so maybe different too.
IDK how close you can run to the radiator, 3/4 inch would seem pretty close. I went back out & measured a stock clutch fan that came of the original motor it is 3 inches. The first one I’d a Hayden heavy duty clutch.

Good luck!
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Old 05-15-2020, 07:42 AM
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Quote:
Originally Posted by 2nd67GTO View Post
I’ve installed the complete AC rubber flap kit. The rad is sealed to the core support.
You have the tall core 17 1/2" & using the steel baffles ?

  #9  
Old 05-15-2020, 09:58 AM
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Quote:
Originally Posted by Murf View Post
The clutch fan is 3 1/4 inch as best as I can measure. My aluminum radiator is 5 1/4 inch from face of water pump pulley. I am surprised that system would eat up an inch but IDK. Mine is a 65 tho so maybe different too.
IDK how close you can run to the radiator, 3/4 inch would seem pretty close. I went back out & measured a stock clutch fan that came of the original motor it is 3 inches. The first one I’d a Hayden heavy duty clutch.

Good luck!
Murf


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Thanks for those measurements, I do appreciate you taking the time.

Sounds like it would be pretty tight. I found a short Hayden clutch, so all’s not lost.

I think the thicker pulley and pulley cover is where I lose the real estate.

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In the works; 400 based 468 Stroker. 4 Bolt mains, Fully forged rotating assembly, KB flat top, custom ground Comp hydraulic roller, KRE 85cc, 310 CFM heads, FAST multi port EFI.
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Old 05-15-2020, 09:59 AM
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Quote:
Originally Posted by chrisp View Post
You have the tall core 17 1/2" & using the steel baffles ?
Yes, tall core and all steel baffles in place.

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If it's worth doing, it's worth overdoing!
In the works; 400 based 468 Stroker. 4 Bolt mains, Fully forged rotating assembly, KB flat top, custom ground Comp hydraulic roller, KRE 85cc, 310 CFM heads, FAST multi port EFI.
  #11  
Old 05-15-2020, 09:43 PM
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imposter imposter is offline
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Default clutch

whats the clutch # and do you have a 11 bolt pump

  #12  
Old 05-15-2020, 11:33 PM
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Quote:
Originally Posted by imposter View Post
whats the clutch # and do you have a 11 bolt pump
Currently running dual electric fans. The short Hayden is #2947. Yes, the pump is the 11 bolt.

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  #13  
Old 05-16-2020, 11:20 AM
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ZeGermanHam ZeGermanHam is offline
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Is there any way you can even run a mechanical fan with the March setup that you have?

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  #14  
Old 05-16-2020, 12:03 PM
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2nd67GTO 2nd67GTO is offline
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Quote:
Originally Posted by ZeGermanHam View Post
Is there any way you can even run a mechanical fan with the March setup that you have?
I don’t know, that’s why I’m asking for minimum distance. It appears that if I remove the WP pulley cover I can bolt the clutch in. I may have clearance issues with the AC and PS pulley covers.

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Last edited by 2nd67GTO; 05-16-2020 at 12:09 PM.
  #15  
Old 05-16-2020, 12:08 PM
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I’ve ordered the short Hayden HD clutch (#2947) and the Derale #17119 fan. Clutch will be here Monday, fan on Wednesday.

We’ll see!!!

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If it's worth doing, it's worth overdoing!
In the works; 400 based 468 Stroker. 4 Bolt mains, Fully forged rotating assembly, KB flat top, custom ground Comp hydraulic roller, KRE 85cc, 310 CFM heads, FAST multi port EFI.
  #16  
Old 05-16-2020, 02:10 PM
Murf Murf is offline
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Quote:
Originally Posted by 2nd67GTO View Post
I’ve ordered the short Hayden HD clutch (#2947) and the Derale #17119 fan. Clutch will be here Monday, fan on Wednesday.

We’ll see!!!


Good luck! Remember I’m pullin for ya. I’m sure you won’t have anymore cooling problem if you can fit it in there.

Murf


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  #17  
Old 05-17-2020, 01:30 AM
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Jack Gifford Jack Gifford is offline
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Just throwing an idea out there-
Is it possible that the electric fans cover so much radiator area that they restrict flow through the radiator at cruising speed? 55 mph should move a huge volume of air through a radiator- if not restricted. [No electric fan could free-wheel fast enough to keep up with 55 mph air]

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  #18  
Old 05-17-2020, 10:13 AM
Murf Murf is offline
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Quote:
Originally Posted by Jack Gifford View Post
Just throwing an idea out there-
Is it possible that the electric fans cover so much radiator area that they restrict flow through the radiator at cruising speed? 55 mph should move a huge volume of air through a radiator- if not restricted. [No electric fan could free-wheel fast enough to keep up with 55 mph air]


Yes, that’s what I think is going on. I’ve seen it on other cars. I think that is why the OP is going to try a mechanical fan.

Murf


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  #19  
Old 05-17-2020, 12:55 PM
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Quote:
Originally Posted by Jack Gifford View Post
Just throwing an idea out there-
Is it possible that the electric fans cover so much radiator area that they restrict flow through the radiator at cruising speed? 55 mph should move a huge volume of air through a radiator- if not restricted. [No electric fan could free-wheel fast enough to keep up with 55 mph air]
After lots of reading here and elsewhere, the consensus seems to be the flat design of the CC shroud and the fact it's only 1/2” from the core blocks a lot of the air at highway speeds. The SPAL fans have a relatively small hub, so probably not the fan itself restricting the airflow.

Marshal

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In the works; 400 based 468 Stroker. 4 Bolt mains, Fully forged rotating assembly, KB flat top, custom ground Comp hydraulic roller, KRE 85cc, 310 CFM heads, FAST multi port EFI.
  #20  
Old 05-17-2020, 12:58 PM
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Quote:
Originally Posted by Murf View Post
Yes, that’s what I think is going on. I’ve seen it on other cars. I think that is why the OP is going to try a mechanical fan.

Murf


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Exactly! Thinking of ditching the shroud and strapping the fans directly to the radiator leaving the rest of the core to free flow while cruising. The more I look at things the less hope I have for getting a properly placed fan into a shroud.

Marshal

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