47-55.1 Electric fan setup?

[Matt_50]

With a new water pump in and the radiator installed, I'd like to maybe go with an electric fan set up if I can get it to fit. Nevermind the top radiator hose, still need a different thermostat housing...
Currently no A/C but I plan to get one in the future.

I know absolutely nothing about fans. What size do I need? Fan shroud? One fan or dual? CFMs? Which brands are good, which are bad?

I tried to get some good pictures. Looks like the core is 20 tall and a little over 19 wide. Looks like a little over 2.5 inches between radiator and water pump. There is about 14 inches or core above the water pump.

Any advice you guys have would be awesome.

[MiraclePieCo]

It has been my experience that advertised CFM ratings are mostly baloney - except for Spal. Spal fans pull so hard that they'll almost suck your truck down the road like a propeller on an airplane! They're worth the extra money.

You have plenty of room. Get the widest fan that will fit. Single will work fine. Mount it as high on the radiator as possible. They say S-curve blades are quieter. Thermostatic switches are convenient; you never have to worry about turning them on. They come with relay kits.

I'm glad to see you using the stock style radiator; they have lots of coolant capacity. I have a hard time getting my motor above 140 degrees.

[Matt_50]

Should i make a fan shroud?

[Matt_50]

And if spal is reliable on their cfm ratings...

Do I need the recommended 2500 cfm? I don't want to go broke but I want a good reliable fan that doesn't sound like I'm about to fly.

[joedoh]

I will try to use a clutch fan until it just doesnt fit. you dont look to have a lot of room there.

a clutch fan is deeper than a flex fan, but it will turn off when not needed, a flex fan is always cutting air.

if electric is all that will fit, most have enough shroud on them and dont need one that covers the whole rad. those will actually restrict airflow when the fan is off.

using a fan controller is better than a simple thermo switch, but a good thermo switch and relay is pretty reliable too. They sell an import upper neck fitting that has a spot for a switch if your intake doesnt have a spot.

I use curved blade generic fans when I cant use a clutch fan.

[popstand]

Modern cars use electric fans not clutch fans. Actually, the clutch fans were not trouble free. I replaced a few of those things in my 60’s gm cars. The clutch fan in my old van is noisy as hell first thing in the morning.

I installed a Derale 16516 electric fan in my ’53, this is 16 inch, 2175 cfm, I installed it ‘pulling’ with no shroud. The 16 inch pretty much covers the radiator and looks nice.

In my truck with a 350 V8, a water pump fan, even if it would fit, would be pretty low to the radiator. Looks like yours is the same. I don’t have a/c.

Electric fans can run after you shut off your motor to continue cooling.

You might want to do a boneyard search for an electric fan package. Maybe some of the guys on the forum have done this. Some of the oem fans are two-speed.

[65blackfleetside]

2nd vote for spaL top of the line fan. Don't waste your money with chinese junk fans.
If you don't have a shroud yet you can make one for less than $30.00 .
Do you have a GFS commercial food supply store near you? They sell the large commercial grade aluminum baking /cookie sheets. One off the shelf fit my new aluminum radiator perfectly and I was limited on space like you. Just cut your hole for fan. mount fan to back of baking sheet with small lock nuts and bolts. The original flange of sheet mounts perfectly to back of radiator. My truck is at the painter or I would post picture. When I show people the shroud they have no idea that it was a baking sheet.

[joedoh]

Originally Posted by popstand

Modern cars use electric fans not clutch fans.

sure do. some because the engine is transverse (the crank is parallel to the front wheels and a mechanical fan would be blowing out the side) some because of packaging where a large cooling fan would not fit. there are still clutch fans in service, usually in the most extreme duty cases.

also, let it be said that all oem electric fan setups, every one of them, have millions of dollars of R&D by hundreds of engineers involved with all aspects of the fan turning on and turn off, software coding, cooling efficiency, reliability, servicing, testing in extreme climates and a lot of other things that the home builder guy picking a fan from summit and a thermo switch from amazon is not concerned with.

but I agree he doesnt have room for a clutch fan.

[Matt_50]

I'm assuming an electric fan is preferred over a flex fan because the flex fan is always going right?

Derale is another brand I've come across that sounded like good quality. 2175cfm is enough Popstand? For a regular putter around occasional highway 350?

Does the cfm change if I am using the trans cooler in the radiator?

I'm still confused on a shroud. Would I want to cover the the whole Radiator? From my searches I found a few guys did flaps. Or do I start with no shroud and go from there?

Joedoh you mentioned using generic fans, I have no idea which ones are junk or not.

[NorCalGal]

This is what I used a delta pag programmable

[NorCalGal]

Oh and 2.7 inches thick

[Matt_50]

I have been searching and searching..

I'm trying to not only find a good all in one kit, bit also looking to see what others have done.

Apparently solidaxle found a mopar fan he put in I think three trucks.

[MiraclePieCo]

My water pump mounted mechanical flex fan will never have a thermostat, wiring, clutch or motor failure. I've had all those things fail on modern fans. The only thing that could fail on a mechanical fan is the belt, and that drives the water pump too so you'll being stopping soon anyway.

Just another example of old-fashioned manual stuff being more reliable than complex modern technology, as I've been debating with Dan in Pasadena.

[MiraclePieCo]

Originally Posted by Matt_50

I'm assuming an electric fan is preferred over a flex fan because the flex fan is always going right?

Derale is another brand I've come across that sounded like good quality. 2175cfm is enough Popstand? For a regular putter around occasional highway 350?

Does the cfm change if I am using the trans cooler in the radiator?

I'm still confused on a shroud. Would I want to cover the the whole Radiator? From my searches I found a few guys did flaps. Or do I start with no shroud and go from there?

Joedoh you mentioned using generic fans, I have no idea which ones are junk or not.

When researching electric fan specs, look at amperage rather than CFM. Most CFM stats are made up; amps is the real indicator of a fan's pulling power.

Electric fans generally have a built-in shroud. They are adequate to align air flow without blocking ambient flow through the radiator like a full coverage shroud.

Derale is a decent economy brand.

As far as fan location near the bottom of radiator goes, it hasn't seem to hurt my truck's cooling capability at all. In fact, if you look at the original factory fan setup from GM (below), they were quite low on the radiator:

[Matt_50]

Look at the amps? What range should I look for?

Are flex fans bad about falling apart? Would a flex fan interfere with wanting to use the radiator's trans cooler? I mean where the connections are?

[Matt_50]

And being low on radiator like you said... from searches, a lot of people say a fan should cover 70% of the radiator.

Is this true?

[Volfandt]

I'm running a SPAL 16" electric fan on a stock 49 GMC radiator with a 350 and unless I'm idling for an extended time (long red light, drive through window) or I'm running over 60mph the fan never comes on. The sender is 200 on / 185 off. I also added a manual override toggle switch in case of sender failure.
Space and a low mounted 350 dictated the electric fan. So far after 1 yr no heat related problems...

In the pic above of the Stovebolt engine I believe thats probably a 55 or later 235 or 261 with the low waterpump, thats why is so low and not centered on the rad.

I'm attaching a pic of a stock 216 in a 49 3100 with the high mounted waterpump which centers the fan on the rad. I run a 160 thermostat in that 216 and never get above 185, even on 90 degree days. It's generally centered at 180...

[Matt_50]

Do you know the part number or cfm of the spal?

[NorCalGal]

Originally Posted by MiraclePieCo

My water pump mounted mechanical flex fan will never have a thermostat, wiring, clutch or motor failure. I've had all those things fail on modern fans. The only thing that could fail on a mechanical fan is the belt, and that drives the water pump too so you'll being stopping soon anyway.

Just another example of old-fashioned manual stuff being more reliable than complex modern technology, as I've been debating with Dan in Pasadena.

I have twice in my life seen where a flex fan blade has come off while running and shot out through the metal hood. I cringe every time I see people stand in line with the fan while the motors running with the hood up. Odds are it won’t happen but I know it is possible

[Matt_50]

Yea, that's a bit scary.

What are yalls opinions on Be cool, flexalite, permacool?

I know a 30 dollar eBay fan is probably crap... I'm just trying to get an idea of what's brands to look at.

[joedoh]

i saw an emergency room show a few years ago and the guy came in mostly decapitated from a flex fan, but still alive somehow. didnt live long though. i dont like them, because they are always "on"


I use the cheap ebay fans when I need one, the s curve fan is the same as a flex a lite curved blade fan, I had one in a box to compare. I worked in china in engineering retail products, when they finish "your" run of parts, they do a run of "theirs" which is the same part without the branding. not always, sometimes cheap is cheap, but the s curve fans I have used are still kicking and working great.

remember amperage not just to compare output but also on what you have available. a high speed fan can be 30-40A of current, whats your alternator size? 90A is common. also wiring, 30A is 12ga stranded min, no matter if the fan has 16-14ga on it. you will need a relay for the thermo switch.

that setup norcalgal shows is a real honey, its worth it to buy the better controller and brushless fan. I have spent up on the variable speed controller in the past because it has infinite speeds.

[Matt_50]

I'm not sure what is good or what sucks on eBay. Take a look at this for example.

https://rover.ebay.com/rover/0/0/0?m...2F253110386902

[NorCalGal]

Originally Posted by Matt_50

I'm not sure what is good or what sucks on eBay. Take a look at this for example.

https://rover.ebay.com/rover/0/0/0?m...2F253110386902

My husband paid about $350 for the whole set up ,it draws 12.5 amps. There are way cheaper solutions out there. Looks like the biggest complaint by people purchasing that item was that it had no instructions.
I would think someone like joedoh or skymang who have put several of these together would be your best source.

[Daze57]

https://the-fan-man.com/product/side...-to-cart=18532

check this out -----see if this helps out

[NorCalGal]

Looking at skymangs build the fan looks very similar to the one you linked to on eBay....hard to tell. For the price it’s worth a try!