Electric Cooling Fan Conversion

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Fukitol

Newbie
Joined
Sep 3, 2018
Messages
28
Reaction score
8
Location
Fl
Could you give me the Dorman part # for your fans please? I like the way they look and personally have had better experience with adapted stock fans vs aftermarket, unless you buy high end. I know the imperial fans we sell st work are useless as a primary puller
 

ericinga

Newbie
Joined
Mar 23, 2018
Messages
27
Reaction score
9
Location
Metro Atlanta
Could you give me the Dorman part # for your fans please? I like the way they look and personally have had better experience with adapted stock fans vs aftermarket, unless you buy high end. I know the imperial fans we sell st work are useless as a primary puller
I used 620-634 which is the same as the Four Seasons 76034. The local Autozone price matched to the Rockauto price of $134.

Sent from my SM-G950U using Tapatalk
 

big_mike

I'm Awesome
Joined
Sep 6, 2011
Messages
857
Reaction score
162
Location
Skiatook, Ok
Unless you just wanna spend the cash you can get good working set of LS fans from a salvage for $60-75 usually.
 
Last edited:

L31MaxExpress

I'm Awesome
Joined
Apr 21, 2018
Messages
5,892
Reaction score
7,542
Location
DFW, TX
The other option is a thermostat housing from an 80s truck. They have a 3/8" NPT fitting for the Thermal Vacuum valve cast and tapped into them.
 

Supercharged111

Truly Awesome
Joined
Aug 20, 2015
Messages
12,617
Reaction score
15,245
Under the thermostat is best. heres a pic of the setup i just finished for my truck.Im not great at shaping sheet metal.
You must be registered for see images attach

That shroud looks good, but it won't flow all that well with the fans off. Trap doors are your friend there, they blow open at speed and get sucked shut when the fans run. I deleted the stock dual fans on my Z06 and installed a Spal single with no shroud and coolant temps dropped from 194 to 187 highway summer. It'll suck a piece of paper off the floor into the front of the radiator too. My half ton has a Mark VIII fan but it only recently started working right (my fault). It'll blow ice cold at an idle and coolant temps are rock solid in traffic. Only question now that it's doing its thing is stop and go towing.
 

Schurkey

Supporting Member
Supporting Member
Joined
Jan 14, 2018
Messages
10,970
Reaction score
13,755
Location
The Seasonally Frozen Wastelands
I just would not be able to live with the jb weld on the housing. I would be to concerned about it leaking.

If you want to use the head plug and it is stubborn just heat it with a torch for a bit and try again, it should come loose.

I personally would never have a coolant temperature switch on that side of thermostat. I care more about the engine temperature rather than when the thermostat opens. The only time that sucker is going to get any heat is when the thermostat actually does open. If that thermostat sticks closed you'll never get any cooling to it and you'll bake an engine in a heartbeat.

If a thermostat is stuck closed there's no fan big enough to cool the engine block enough to keep it from overheating, just sayin.
THANK YOU. You guys saved me a lot of typing.

Having the temp sender on the wrong side of the thermostat is a disaster waiting to happen. Having it epoxied in place using cheap epoxy is a disaster waiting to happen.

Heat the plug in the head cherry red, and let it cool. Propane will NOT be hot enough. MAPP-substitute might be hot enough. I would use oxy-acetylene. It'll likely screw right out without too much trouble afterwards. DON'T heat the head casting--heat the plug.

GM used to use several thermostat housing designs that had a threaded boss, they were available (inexpensive) in the aftermarket. Never needed one, bought one by accident years ago. I imagine they're still available. GM put a thermo-vacuum switch in the boss. At least that way you wouldn't need epoxy. But that location is the WRONG place for a temp sensor. If the thermostat sticks shut, the engine will overheat and the temp gauge will give you zero indication of the problem.

These may not be the part number you'd use, but it gives the idea.

https://www.napaonline.com/en/p/NDP60529221

https://www.napaonline.com/en/p/BK_6051075






Truthfully, it was a MISTAKE to remove the fan clutch system with it's fan shroud. You've spent a lot of time, money, effort, and enthusiasm replacing what the engineers designed, and you're unlikely to achieve any substantial gains--and VERY likely to have made things worse.

Did you remember to wire a system to engage both fans when the A/C is operating?
https://www.gmt400.com/threads/refrigerant-blowing-out-of-ac-compressor.42694/

You must be registered for see images
 
Last edited:
Joined
Dec 10, 2016
Messages
518
Reaction score
160
Location
Hampton, VA
That shroud looks good, but it won't flow all that well with the fans off. Trap doors are your friend there, they blow open at speed and get sucked shut when the fans run. I deleted the stock dual fans on my Z06 and installed a Spal single with no shroud and coolant temps dropped from 194 to 187 highway summer. It'll suck a piece of paper off the floor into the front of the radiator too. My half ton has a Mark VIII fan but it only recently started working right (my fault). It'll blow ice cold at an idle and coolant temps are rock solid in traffic. Only question now that it's doing its thing is stop and go towing.
I'll have to see what i can fabricobble. And i used to have a mark viii fan and shroud, but i used it to make an electric mower.
 

ericinga

Newbie
Joined
Mar 23, 2018
Messages
27
Reaction score
9
Location
Metro Atlanta
Hey man

Thanks for the feedback. I already moved the sensor to lower radiator hose using the adapter mentioned in a previous comment. I was never really happy with the t-stat housing mount but it was the solution that worked. (thanks everyone for the feedback.) I found one plug available in the driver's side head. The temp gauge sender is located in that spot. Don't see another one to use. There is a plug in the top of the water pump but I couldn't get it out. (Don't have an oxy-acetylene rig.)

I prefer the engine coolant based sensor over the probe based sensors in many of the conversion kits. Maybe attaching a sensor to the outside of the radiator works but it does not seem to be the best solution. As many have pointed out, you have to place it in the correct location of the coolant path.

As for the fans, both are wired to separate relays and fuses. Both fans are activated by the temp sensor. So, yes, both fans are engaged with the AC running.

The planned improvement was an increase in fuel economy. After running it 4 days this week, economy improved 2 MPG. I drive the truck about 100 miles a day or 500 miles a week. So, the gas savings will pay for the conversion cost after 8 weeks or so.

Appreciate your comments and perspective.

Eric

THANK YOU. You guys saved me a lot of typing.

Having the temp sender on the wrong side of the thermostat is a disaster waiting to happen. Having it epoxied in place using cheap epoxy is a disaster waiting to happen.

Heat the plug in the head cherry red, and let it cool. Propane will NOT be hot enough. MAPP-substitute might be hot enough. I would use oxy-acetylene. It'll likely screw right out without too much trouble afterwards. DON'T heat the head casting--heat the plug.

GM used to use several thermostat housing designs that had a threaded boss, they were available (inexpensive) in the aftermarket. Never needed one, bought one by accident years ago. I imagine they're still available. GM put a thermo-vacuum switch in the boss. At least that way you wouldn't need epoxy. But that location is the WRONG place for a temp sensor. If the thermostat sticks shut, the engine will overheat and the temp gauge will give you zero indication of the problem.

These may not be the part number you'd use, but it gives the idea.

https://www.napaonline.com/en/p/NDP60529221

https://www.napaonline.com/en/p/BK_6051075






Truthfully, it was a MISTAKE to remove the fan clutch system with it's fan shroud. You've spent a lot of time, money, effort, and enthusiasm replacing what the engineers designed, and you're unlikely to achieve any substantial gains--and VERY likely to have made things worse.

Did you remember to wire a system to engage both fans when the A/C is operating?
https://www.gmt400.com/threads/refrigerant-blowing-out-of-ac-compressor.42694/

You must be registered for see images
 
Top