I'm working on upgrading to an electric fan in my 65 Barracuda and was wondering what components others were using. I have a V8 rad which has a 22" W x 17" H core. There is about 2" between the rad and the water pump pulley bolts and about 2.5" between the rad and the hood latch support. I switched to the 195°F thermostat for better fuel efficiency and more cabin heat for fall driving.

The thickness of aftermarket electric fans seems to be more than 2.5" so it doesn't look like I can use a single large (16" or 17") fan centered on the rad. I can probably use a pair of 10" fans on the front or back. It looks like I can probably also use a 14" or 16" in the back (puller - offset away from the water pump) and/or a 14" or 16" on the front (pusher - offset to the opposite side).

I see that Painless Performance has a pulse width modulated (PWM) controller (PN 30140) that controls 2 fans (each up to 35A continuous / 70A peak). Hayden's PN 3654 allows staggered operation of 2 fans (2nd fan comes-on 10°F above 1st).

I'm not sure if I would really need more than a pair of 10" fans since they would probably only be running when stopped in traffic and the engine is pretty much idling.

What fans are you using and how do you control them?

Fan from a 91 caravan wired up like this http://www.slantsix.org/forum/viewtopic.php?t=38827 I used a temp switch from jegs. Dont get a switch from jegs I went through two or three for i got one that worked right.

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85 d-100 HEI 2BBl
06 Toyota Corrola

I used a 16" ProComp for about 5 years, yes, it fits barely only about a 1/4" to spare.
One day I finally got smart after putting my hand behind the running fan on a super hot day and found the bottom half just ran cold air. The core was cold. The top of the tank was blazing hot! So I thought, this is a waste (the 16" fan ran twice as long since the top half of the fan was the only part doing the cooling) and switched to two 10" fans up at the top where the heat is and where they could do some good. The two fans run less and get the job done much faster. They draw a lot less amperage too! compared to one 16" fan and there is plenty of room!

To control them I have two thermostat switches screwed in the tank. I tried the GM 200 degree switch, but that is a little too warm so I run the 185 switch primarily and use the 200 as back up. Both are wired together so the 200 is the fail over. I leave them armed with a switch inside the car with a light so I know when they are on, plus a manual override on switch. I leave them armed 100% of the rime. It is pretty stupid proof. Running a 180 degree stat. The air dam helps a lot and keeps the bottom of the radiator nice and cold. I pull the air dam off in the winter for quicker warm up and better mileage. Better mileage comes from the quicker warm ups.....! Check out my wiring schematic in the Engine FAQ. Hot starts after heat soak are immediate! no cranking......

I ordered the fans from eBay and the switches from Summit Racing. The two tens have been running a couple of years now and do a great job. They are a little noisy being a straight blade design. I can't hear them inside the car while driving at all, but after the engine is shut off in quiet parking lot you can sure hear them! If you want a quieter fans, go with an "S" blade design. I think my fans were around $35. The screw in the radiator temp switches are about the same.

Click on the red link below my name to view photos of both setups.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

I forgot to mention be careful that you dont run your power from anywhere that it could back feed into the ignition wiring when its winding down or else you will have a intermittent dieseling problem you cant figure out.

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85 d-100 HEI 2BBl
06 Toyota Corrola

Good point!

Run a line right off the battery terminal fitting on the starting solenoid to your relay over to the fans for the shortest possible wiring.
Use my simple wiring schematic in the Engine FAQ.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Use a good relay, designed for the job, a single big fan draws a lot of current when starting, and not all relays are designed for carrying a high load for extended time, like feeding a fan in heavy traffic in hot weather. Most good relays has a built-in circuit that prevents back-surge.

Take a look at a factory fan relay's size and heft compared to their other small relays, designed for only carrying ordinary small loads.

Olaf

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Aspenized

I have used Flex-a-lite and Hayden "parts store" fans from 12" to 16" on my cars. 14" seems to flow enough for about any Slant, even with a stock type radiator (in good condition). If you have a big alum radiator, a little 12" is usually fine. I either run mine manually off a switch, or with a thermostatic switch. Those damn things (aftermarket) seem to blow out after a fairly short period, so mostly I just do it manually. Usually, I use a relay, but not always. All of mine have a 30A fuse inline.

Lou

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Home of Slant6-powered fun machines since 1988

Fans, if not covering the radiator, should be mounted low. This way the ram air isn't impeded. If the air and coolant are still hot at the bottom the fans can do their job. This is why the coolant temp sensors are OE located in the cold tank.

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Joshua

Great advice, Josh. Yes, I always mount mine as low as possible.

Lou

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Home of Slant6-powered fun machines since 1988

On my previous EFI '75 Dart, I had a pair of 10" Hayden pullers. I used three relays to switch the fans- low speed was series feed(controlled by the EFI computer). Hi speed was parallel feed controlled by a temp switch mounted in the stat housing (I thumbed thru a Standard Motor Products catalog until I found a style & temp for a switch I liked)

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63 Valiant Wagon
225 - 4 bbl

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

I have four 10" fans on an aftermarket Summit rad. One is on a thermostat and the rest are manual on/off. Relayed power is picked up direct from the battery.

Also, with the possible increased electrical demand, don't forget to check your alternator and wiring harness for the increased load.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

Thanks for the replies so far. To answer the above posts:

carlherrnstein: Thanks for suggestion to stay away from off-brand controllers. I thought I would stick with brands that specialize in cooling systems. I read Ted's Electric Fan FAQ and was planning to use a relay triggered from IGN1 to power it. However, I don't think I'll run a over-ride switch inside the car to manually turn the fan on. An Off-Auto-On switch makes sense beside the fan though.

Aggressive Ted: I had thought about using relays and temperature switches to control a pair of fans but, since I'm currently using a 195°F thermostat, I haven't yet found a pair of suitable temperature switches. If a pair of NPT temperature switches cost ~$35 a piece, the $49.95 (Summit Racing) Hayden PN 3654 dual fan controller makes more sense.

olafla: The commercial fan controllers all seem to use built-in relays to control the fans. I thought about using external relay but I think it might be redundant.

Dart270: I was hoping that I could get by with a smaller fan, especially since they fit better and draw less current. Do you recall which aftermarket switches kept blowing out?

Joshua Skinner: I hadn't considered the vertical placement of the fans. On my car, although the valence panel is is fairly unobstructed, the licence plate could reduce ram air flow. I'm not sure why you would you put the coolant temperature sensor at the bottom tank instead of top tank if we're trying to control water temperature in the engine. I would rather put the sensor in the head beside the thermostat.

WagonsRcool: Do you have a link to the Standard Motor Products catalog?

slantvaliant: That was the arrangement I was thinking about with 2x12" or 2x14" fans.

Shaker223: I'm also planning on upgrading to the 120A Denso alternator.

From earlier topics, I noticed that some people have removed their mechanical fans and have no overheating issues while in motion. I'm pretty confident that I only need fan operation while stopped in traffic.

On FABO, I noticed there was a lot of postings about using huge CFM electric fans on 26" wide aluminum rads to get adequate cooling. I don't have an overheating problem with my 22" wide rad and my OEM fan seems to move an adequate amount of air. For an idea of how much CFM I really need, I did a quick calculation to get into the ballpark. My 4-blade fan is 16" in diameter with a blade length of 5" and a blade thickness of 1.5". Eyeballing the pulleys, the crank pulley is 7" while the fan pulley is 6.5". With an idle speed of 550 RPM in drive, I calculate that the factory fan moves about 218 CFM of free air and actually probably a bit less. Hayden's 10" Rapid-Cool fan (PN 3670) moves 650 CFM of free air and 500 CFM across a rad. If I use a pair of 10" fans, it looks like I'll have over 4-5 times the air flow of my factory setup.

I contacted SSDan about electrical upgrades (including his RIK-2 relay-lighting upgrade) and he suggested using the Flex-a-Lite variable speed controller. Summit Racing has this item (PN 31165) for $112.97. However, the VSC comes on at 60% for 2 fans whereas the Hayden 3654 with 2 fans effectively comes on at 50%.

Painless Wiring's PN 3140 is similar to the 31165 but seems to be unavailable for at least a year (reliability issues?). I've read about failures with the VSC and Delta Current Control fan drives. Does anyone have any experience with variable speed drives?

Besides the 91 Caravan, it looks like others have used these fans too:

• mid 90's Ford Taurus
• Lincoln Mark VIII
• late 90's Cadilac STS

I had an electric fan off an escort mounted in front of the rad. It freewheeled itself to death before I ever turned it on. I removed it and went fanless for a number of years. Stock rad.....no city driving.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

At least one of the switches was Flex-a-lite. Don't recall others. Probably won't bother with another of those. Once I get MSII or MSIII working on a car, I can use programmable outputs to control fan. That or manual for me. If a part won't last at least 40k street miles for me, I don't want it.

Lou

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Home of Slant6-powered fun machines since 1988