Converting to electric fans

[foriamclever]

I'm looking to convert to electric cooling fans, what with the ridiculous Texas heat and all. Can anybody give me any advice as to which fan I ought to go with? I'm running a fairly stock 350 with headers, no a/c, with an external transmission cooler. I'm seeing a whole lot of different products and prices. I wanna keep it as cheap as I can cause I'm poor, but I don't wanna buy some hunk of crap that won't work. Thanks in advance for the help.

[71meangreenc10]

I have the jeep mod fan in mine, fan was less than 50 bucks, fits in the shroud perfect with a little help, I did buy a better fan control unit from jegs, it was $99 and has adjustable contols.

Smitty

[Lee H]

Is your ride over heating? Not trying talk you out of fans but if you don't have a lot of money don't spend it on fans. A properly working stock system will keep your ride as cool as fans.
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[kevmic28]

What sized radiator do you have in the truck? you might start there for your cooling issues. I have the jeep fan conversion in my truck. Also a 4 row radiator new water pump, good hoses, and vintage air ac. I had been tracking down a heating issue that turned out to be a bad gage.
Cross reference heating issues with a infrared thermometer to make sure its not a bad gage before throwing money into it.

[foriamclever]

Where can I find a thread or an article about the jeep conversion? I haven't heard about it.

[kevmic28]

http://67-72chevytrucks.com/vboard/s...d.php?t=458218
The original is in the faqs section

[AirSpeed]

Not trying to Hiest the thread but what are the benefits of an electric fan over stock? Is it just the constant speed of the electric fan or the reduced drag on the engine from the stock fan? Is there an increase in power without the stock fan?
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[truckindude]

Originally Posted by AirSpeed

Not trying to Hiest the thread but what are the benefits of an electric fan over stock? Is it just the constant speed of the electric fan or the reduced drag on the engine from the stock fan? Is there an increase in power without the stock fan?
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that was the only reason i put electric fans on my 92 p-up... more power and better mileage...i bought the cheapest one with the most cfm for good cooling. otherwise if you have a good fan clutch the regular fans work fine. the clutch helps with gas mileage too.

[AirSpeed]

Originally Posted by truckindude

that was the only reason i put electric fans on my 92 p-up... more power and better mileage...i bought the cheapest one with the most cfm for good cooling. otherwise if you have a good fan clutch the regular fans work fine. the clutch helps with gas mileage too.

Can you actually feel an improvement in horsepower, is actually a difference you feel right away or is it only going to be seen in gas mileage?
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[truckindude]

i don't know if you can feel it a LOT, but to me there was a difference especially towing or using cruise control on bigger hills.

[Lee H]

Average HP increase with electric fans is 10-15hp. It takes at least 25hp to feel in the seat of the pants. As far as mileage, unless you track it regularly, you'll never notice the difference. Electric fans are a nice upgrade but don't expect to notice higher HP or to recoup the the cost with higher mileage. Also don't do it to lower the operating temp, find the real problem and correct it.
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[AusTx68]

It was 102 today in Austin. How hot are you running in this heat? If I get stuck in stop-and-go traffic my temps easily reach 210. Once I get going I drop to 185. That's with aluminum radiator and twin 10" fans. I plan to swap out my 160 t-stat for a 195 to give the water a chance to cool.

[fastwillie 696969]

pushing or pulling

[madchopper]

I pushing or pulling better? Just bought a pulling dual 12" and dont really know the difference. I plan on using it as a pulling unit but might change is pushing is better.

[MagmaJct]

Originally Posted by AusTx68

It was 102 today in Austin. How hot are you running in this heat? If I get stuck in stop-and-go traffic my temps easily reach 210. Once I get going I drop to 185. That's with aluminum radiator and twin 10" fans. I plan to swap out my 160 t-stat for a 195 to give the water a chance to cool.

Going to a cooler thermostat won't help your problem. If the water is 310 then your thermostat, if it's working correctly, is already open all the way. The thermostat will set the minimum operating temperature, not the maximum.

Something else may be going on here.

But to continue the fan discussion, the benefits of an electric fan have more to do with saving engine power when the engine doesn't need extra cooling. For example, when cruising there is enough ram air through the radiator to cool the coolant.

With a belt driven fan engine power is always being used. A clutch helps with this by allowing the fan to "slip". But some power is still being used. If the fan were to be removed altogether the power used it gone.

An electric fan does this by completely shutting off when air movement isn't needed. But when vehicle speed is too low to provide enough air flow the electric fans take over assuming the fan's thermostat is installed properly.

[68 IRON]

Magma is right on! T-stat regulates when the engine starts going to the well to get a drink (I mean start cooling). Do you run a shroud or clutch fan? These would be questionable if things get hot when you stand still. The shroud funnels all the drawn air through the single point needed and the fan clutch...well if it aint engaging, you don't get air flow. Maybe a blockage or anything/ everything combined. Also check the accuracy of your gauge....mine misled me. Hope this helps.

[68 IRON]

On another note, just listen to the fan when you rev your engine. It pulls harder the faster the engine turns. When you free that up at highway speeds and the fact its generally only running (the electric fan) when stopped it saves some in fuel and HP.
Not to mention taking the somewhat unbalanced weight off the pump shaft which kills 'em. I'm gonna do it....hopefully soon!

[foriamclever]

I'm running easily 210 in the heat. If I sit, I'm flirting with 220. My gauge could be wrong, as it is an after market installed by the previous owner. I just installed a new water pump (old one was leaking and the pump shaft bearing was worn as hell) but haven't noticed a difference in temp. Radiator isn't leaking, coolant is clean and full. Clutch fan, no shroud. The fan spins on the clutch with not much effort by hand, so I assume that it's in working order. I have a shroud, but the fan is too big, and I'm having a bit of trouble locating a replacement. I figured if there is an appreciable benefit for going electric I'd go with that. As far as the radiator, it appears to be stock.

[foriamclever]

Oh, and thanks for the link to the cheap electric fan build, kevmic.

[Dunenutt]

Not having a shroud is a huge issue. The clutch should spin by hand fairly easily, when cool. When it is hot, it should be much stiffer.

[AusTx68]

Originally Posted by foriamclever

I'm running easily 210 in the heat. If I sit, I'm flirting with 220. My gauge could be wrong, as it is an after market installed by the previous owner. I just installed a new water pump (old one was leaking and the pump shaft bearing was worn as hell) but haven't noticed a difference in temp. Radiator isn't leaking, coolant is clean and full. Clutch fan, no shroud. The fan spins on the clutch with not much effort by hand, so I assume that it's in working order. I have a shroud, but the fan is too big, and I'm having a bit of trouble locating a replacement. I figured if there is an appreciable benefit for going electric I'd go with that. As far as the radiator, it appears to be stock.

Texas heat with a stock setup, I think those are decent numbers. My 87' GMC will rise near 220 with the a/c running and cruise at 210.

[67cheby]

AUStx68... have i missed your build thread ??? your interior is beautiful, i want to see more of the truck !!

[AusTx68]

Originally Posted by 67cheby

AUStx68... have i missed your build thread ??? your interior is beautiful, i want to see more of the truck !!

Sorry, I never got around to creating a build thread but it's documented in several posts. Check the Gallery for the recent pics: http://67-72chevytrucks.com/gallery/...lery.php?cat=2

[67cheby]

WOW...nicely done

[MagmaJct]

Originally Posted by foriamclever

Clutch fan, no shroud. The fan spins on the clutch with not much effort by hand, so I assume that it's in working order. I have a shroud, but the fan is too big, and I'm having a bit of trouble locating a replacement. I figured if there is an appreciable benefit for going electric I'd go with that. As far as the radiator, it appears to be stock.

Okay, now I have something to work with! In my truck, the fan sits some distance from the radiator. Without the shroud the fan would pull air from around the blades other than through the radiator. This will cause several problems. Some of which would be minimal air flow through the radiator, and hot stale air coming off the exhaust wouldn't be pushed out under the vehicle.

Another problem would be the clutch will be "disconnected" in a thermal sense from the radiator. Consider a properly running engine and cooling system with all the original components in place: The clutch "feels" the heat coming off the radiator. As the radiator heats the air passing through it, the air heats the clutch which is designed to allow more torque from the pump shaft to spin the fan. As engine heat is reduced or vehicle speed increases and the fan isn't as necessary, the air passing through the radiator is cooler which means the clutch allows the fan to "slip". This reduces engine load which improves mileage and performance.

My advice? If you want to keep it mostly stock, it may be easier to find out why the fan/shroud combo you have just won't work together. Is it the fan? The shroud? If you don't mind moving away from the stock look, the electric fan setup would work if the fan is sized right, meaning it covers the radiator properly and the flow (CFM) is correct for the cooling demand of your engine.

I'm poor so I still have the stock setup, so I can't give recommendations as to the proper electric fan and CFM. Good luck!

--Mike

P.S. Missing the fan shroud would be kind of like having a broken duct in your furnace/air conditioner in the return line in the attic.