Electric fan

[53 stickfigure]

The 70 chevy c10 is running a little hot at red lights. I have a pretty good sized radiator and a 160 thermostat but no fan shroud. Ive looked around for a shroud but no luck so far around here. While driving, its in the 90s right now, she'll run about 170 , but go to 200 real quick sitting still. Im thinking about running an electric fan on a 50 amp toggle switch for long stops and before stutting her off. With 10 gauge wire and a 50 amp toggle, will i need a relay? Its only going to be used in maybe, 5 minute intervals. The fan I'm looking at draws 11 amps. Relays are pretty cheap, but if i don't need one, thats $8.00 in gas. I could run a 3 inch fan spacer in place of the 2 inch but I'd still be pretty far away from the radiator. Electric fans are way cheaper than a new fan shroud.

 

[zzrodder]

I think you've already answered your own question, that is the shroud is what you really need. Why add more complexity and wiring with an electric fan - it's really a band-aid solution. It's not that hard to make a shroud, make patterns out of cardboard and duct tape - you dont even need to do any welding, you can just pop rivet aluminum or steel sheet together. to keep the size of the shroud to a minimum, I'd also use the 3" fan spacer.

 

[53 stickfigure]

I think you've already answered your own question, that is the shroud is what you really need. Why add more complexity and wiring with an electric fan - it's really a band-aid solution. It's not that hard to make a shroud, make patterns out of cardboard and duct tape - you dont even need to do any welding, you can just pop rivet aluminum or steel sheet together. to keep the size of the shroud to a minimum, I'd also use the 3" fan spacer.

I think i will fabricate my own fan shroud. I have everything i need.

 

[sneakysnake]

The fan on a switch is fine, unless you forget to turn it off. A relay is used normally to carry the load and to prevent "back feed" from the fan after the ign is turned off.

 

[Old Iron]

I run shrouds when I can and electric fans when I have to.

 

[Skip]

http://www.ebay.com/itm/200-185-Deg...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

I picked this kit up on eBay for my electric fan. All there and cheaper than guessing at it. Installing today, hopefully.

 

[Sam_Fear]

The fan on a switch is fine, unless you forget to turn it off. A relay is used normally to carry the load and to prevent "back feed" from the fan after the ign is turned off.

You need to run the switch through the "Run" side of the switch. But like SS said, when you turn of the ignition, the motor will keep running until the fan slows down - it acts like a generator for the coil at that point.

I've seen that happen with rewired heater blower motors too. It took awhile to figure out the first time I ran across it.

 

[Yankee Transplant]

shroud is the answer , maybe a 180 thermostat also , this will keep the water in the rad a little longer to cool it . if it runs 170 with whats in it now it dont ever close . . My son also has a heating problem , which we are working on , he is running 2 fans and a 160 thermostat it runs 180 till he gets into the gas then it climbs on up from there .

 

[Blue Eyed Devil]

No reason to ever run a 160 thermostat, especially in a SBC. Put a 180 or 190 in it with a fan shroud and watch it idle all day long.

 

[Old Iron]

Yankee, there could be a carb issue there. If the jetting is too lean the engine will run hotter under hard acceleration.
BED is right 180 to 190 stat.

 

[Yankee Transplant]

Old Iron you are correct he does have a different carb on it now with I think 74 jets in it , the engine still gets hot . we are in the process of the thermo change the other carb had 60s in it and we went to 69s but that carb had some issues .Hopefully we can solve his problem

 

[53 stickfigure]

Now that the temperature is in the mid 70s and running the 160 thermostat, its running too cool. I have sunpro gauges, not the best, not the worst, but it stuck on me once and i don't trust it now. Truck is running great now but i need to install a fuel regulator. It wants to flood a little when i shut her off.

 

[Yankee Transplant]

Glad you got the running hot figured out , we havnt yet got ours fixed . going to take the dual fan and shroud off my sons tomorrow and put a big fan with no shroud and see what happens ,got the 180 thermo, in and it run up to 210 or so today so nope the 180 didnt fix it like i was hopping .next I guess we will buy a heat gun and see if maybe we can figure out what getting hot first, We are running out of things to try.

 

[Dr Crankenstein]

Rules of thumb:

- Hot at idle, needs more fan.
- Hot at speed, needs more radiator.

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