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Old 08-06-2017, 10:35 AM   #1
abig84
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mechanical fan woes

so after mounting my v8 in my 51 1ton i kinda screwed up and didnt get the engine as far back as i can (can maybe get another 3/4 inch) so the mechanical fan is into the radiator, you can see in the pic i have it sandwiched in there on the left side and thats even with the pulley off. also half the fan is going to hang down below the radiator






but anyways looks like its going to be way to low anyways and the blades are going to go into the lower radiator hose if i actually bolt it up

so can you even run a mechanical fan on these trucks or electric is just easier?
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Old 08-06-2017, 10:38 AM   #2
vintovka
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Re: mechanical fan woes

pusher electric?
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Old 08-06-2017, 12:57 PM   #3
gigamanx
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Re: mechanical fan woes

Looks like you need to go electric fan. Any reason you're sold on the mechanical fan? I've also seen somewhere, someone ground off those mounting plates on the side and tacked in new ones further forward to tilt the radiator away from the fan.
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Old 08-06-2017, 01:16 PM   #4
joedoh
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Re: mechanical fan woes

looks like you are using a serpentine setup. if you have the long water pump there is a shorter pump that will give about an inch. you may need a new pulley for the water pump, since there are no ribs on the water pump pulley the original pulley may still fit the belt. (it is run by the backside of the belt)

BUT. moving the fan in may let the fan hit the crank pulley. best to do some measuring and see if you have the inch to gain. I am looking at my 4.3 serp setup as I am typing this and there is an inch there, both for the pulley and for the fan, but your results may vary.

most serp systems are reverse flow water pumps, so MAKE SURE you get the right water pump. same with the fan, if you change the fan make sure the blades face the right way.

I dont like the current draw and install complexity of electric fans, a mechanical fan is worth the hp hit for me. never blew a fuse on a mechanical fan.
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Old 08-06-2017, 05:37 PM   #5
dwcsr
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Re: mechanical fan woes

Quote:
Originally Posted by abig84 View Post
so after mounting my v8 in my 51 1ton i kinda screwed up and didnt get the engine as far back as i can (can maybe get another 3/4 inch) so the mechanical fan is into the radiator, you can see in the pic i have it sandwiched in there on the left side and thats even with the pulley off.
but anyways looks like its going to be way to low anyways and the blades are going to go into the lower radiator hose if i actually bolt it up

so can you even run a mechanical fan on these trucks or electric is just easier?
just bolt the radiator to the outer side of the support. modify your upper and lower valance to match. That solves the clearance issue but its still to low. So I would move the radiator to the front and use a Mark VIII or Taurus fan
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Old 08-06-2017, 06:28 PM   #6
vintovka
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Re: mechanical fan woes

A Taurus fan seems to work for me. Brackets to hold fan in position are easy to make.
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Old 08-07-2017, 02:21 AM   #7
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Re: mechanical fan woes

This might be the simple option but I would call and ask if it will work with your engine. Fan shouldn't stick out much more than a half inch from the hub. They do make noise though. [url]https://www.flex-a-lite.com/belt-driven-fans/15-inch-reverse-rotation-race-fan.html[/url

If the 15 inch fan clears the lower radiator hose. On a V8 that may not be an issue it was on my 250 six.

You can run a spacer that allows the fan blades to clear the pulleys and still clear he radiator with room to spare.
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Last edited by mr48chev; 08-07-2017 at 02:28 AM.
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Old 08-07-2017, 10:32 AM   #8
_Ogre
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Re: mechanical fan woes

the easy solution is to get rid of the fan clutch and go with a standard fan
then make a shroud that covers the whole radiator
use the top couple inches of a 55 gal or 35 gal steel barrel for the fan guard and a bit of sheet metal for the shroud
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Old 08-07-2017, 02:57 PM   #9
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Re: mechanical fan woes

https://www.flex-a-lite.com/belt-dri...-race-fan.html Lets see if this link works better on the reverse rotation flex fan.

It still has to clear everything though.
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Old 08-08-2017, 01:18 AM   #10
Lo1dakota
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Re: mechanical fan woes

Electric fan. I use a Champion radiator, their shroud, and a SPAL low profile e-fan sourced through them. I also purchased their supplied relay kit that using a sending unit in a water jacket to kick the fan on. Works perfect. 90 degree days in traffic it never gets over 180.
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Old 08-08-2017, 07:39 PM   #11
dsraven
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Re: mechanical fan woes

if it were me I would mount the rad on the front side of the support and then install an electric fan, like dwcsr suggested. a low mounted fan won't see full rad coverage. like driving with cardboard in front of the rad in the winter. may tend to run hot plus the last one I had with limited clearance on the fan ended up eating a few rads.
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Old 08-08-2017, 09:45 PM   #12
Lo1dakota
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Re: mechanical fan woes

That's why I suggested the Champion setup. I have roughly 1" clearance from the face of my radiator to my water pump pulley. I have champions shroud, and the Spal low profile fan and still have 1/4" to the pulley. Cools perfectly.

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Old 08-09-2017, 07:22 PM   #13
abig84
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Re: mechanical fan woes

Quote:
Originally Posted by Lo1dakota View Post
That's why I suggested the Champion setup. I have roughly 1" clearance from the face of my radiator to my water pump pulley. I have champions shroud, and the Spal low profile fan and still have 1/4" to the pulley. Cools perfectly.

yeah that looks like what im going to have to do. if the fan was centered in the radiator i might try harder using the mechanical fan. but i need to buy a new radiator anyways so might as well get the fan with it

ive always just liked the mechanical fans, they have always worked fine for me and i guess i just hate change.

guess i was just curious if i was missing something but looks like electric is the way to go. i think i measured 3.5 inches from the radiator to the water pump pulley, so hopefully they make one that thin or ill slide the radiator upwards into the support a bit
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Old 08-10-2017, 04:26 AM   #14
Lo1dakota
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Re: mechanical fan woes

I want to say that's right around what my clearance was as well.

Plus side to the electric fans is HP. A standard clutch fan being the best of any fans for parasitic loss of HP still loses around 23hp.


Check out this youtube video from Engine Masters on fans for info.
https://youtu.be/ZXdLgaFXZzs
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