Electric fan setup?
 

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.

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

Should i make a fan shroud?

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

This is what I used a delta pag programmable

Re: Electric fan setup?
 

Oh and 2.7 inches thick

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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. :metal:

Re: Electric fan setup?
 

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:

Re: Electric fan setup?
 

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?

Re: Electric fan setup?
 

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?

Re: Electric fan setup?
 

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...

Re: Electric fan setup?
 

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

Re: Electric fan setup?
 

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:eek:

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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

Re: Electric fan setup?
 

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.

Re: Electric fan setup?
 

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

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

Re: Electric fan setup?
 

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!

Re: Electric fan setup?
 

That 70% figure actually comes from the Flex-A-Lite fan page. https://www.flex-a-lite.com/blog/whi...lt-driven-fan/
It's a good policy, but I'm here to say that I'm actually running a low-mount mechanical fan with a warmed-over SBC and my temp runs a consistent 140 degrees. The outside temperature here has been around 90 this week. Looks like I may actually have to install a hotter thermostat just to get my motor up to temp!

Regarding the tired old "flex fan decapitation" stories: My flex fan is rated for vastly higher RPMs than my motor is capable of; no doubt those fans that came apart were either cheap, damaged, abused, or all three. We know they didn't have a shroud!

I've used both mechanical and electrical fans. In every case the mechanical has cooled better. Plus I take comfort knowing I'll never be stuck on the roadside due to blowing a 15-cent fuse. My fan will never stop working as long as my engine is still running.

.

Re: Electric fan setup?
 

Yea, it is hard to ignore when a lot of people say the same thing... I guess there are probably plenty of people who say other stuff that just don't post.


I'm completely new at a lot of this so I do try to go with the general consensus unless a very experienced person let's me ask a ton of questions lol

Re: Electric fan setup?
 

Ignore me too; laziness and poverty oftentimes compel me to do unorthodox things that are highly condemned on forums. I don't want you mad at me when I recommend something that screws up your truck!

Re: Electric fan setup?
 

removed

Re: Electric fan setup?
 

Thats an awesome picture of how you mounted it too.

Re: Electric fan setup?
 

looks good !!!

Re: Electric fan setup?
 

A fan shroud made from an old T-shirt, fiberglass resin and some aluminum angle and sheet metal scraps.

Fan is a 16" Spal, but you could buy a smaller one and move it around to clear your water pump.

The money side..........

https://talk.classicparts.com/media/...done.7030/full

The back side that I fiberglassed.........

https://talk.classicparts.com/media/...back.7029/full

On the radiator..... (I'd just started sanding the resin to prep for paint)

https://talk.classicparts.com/media/...tted.7023/full

Re: Electric fan setup?
 

What size radiator is that?

Re: Electric fan setup?
 

My problem with shrouds:

An AD radiator core is about 19" x 21" = almost 400 square inches surface area.

A 16" electric fan in the center of a shroud is an opening of only about 200 square inches (A=πr2 or 3.14x8x8).

By covering your radiator with a shroud you have just closed off exactly half your cooling surface to ambient air flow. The entire 400 square inches of radiator front surface must force air through the 200 square inches of fan opening in the shroud. This is why some install passive flaps to allow airflow through their shrouds. IOW they cover the radiator, only to have to devise a system to uncover the radiator.

Yes, I've tried shrouds on my cars, but it seems like my fan runs too much. I've had better luck letting the radiator breathe.

.

Re: Electric fan setup?
 

https://www.ebay.com/p/3-Core-Perfor...d=163168971034 has anyone used this? my "original rad is leaking getting price to recore".. but v8 sits very low with no shroud...

Re: Electric fan setup?
 

MPC - agree with you on fan shrouds that sit right on the radiator - seems like you're leaving some cooling capability on the table that way.

On my T-shirt fan shroud, the face of the fan is about 2" off of the radiator and the clearance all around the sides is at least one inch, so theoretically the big SPAL fan should suck air all across the face of the radiator - probably better in the 200 square inches directly in front of the fan though.

I think you'll find that the flaps on most production fan shrouds are there to let air flow across the radiator at highway speeds. When air pressure from forward speed is greater than what the electric fan can generate, the flaps bypass the fan. I think most production cars with electric fans can turn them off at highway speeds too.

BTW - the radiator in my photo is for a GMC AD truck. GMC engines were longer than the Chevy, so GMC sunk the radiator further into the core support and put a goose-neck filler on it to access the radiator. I believe it is about 1.5" deeper in the shroud than a Chevy.

Re: Electric fan setup?
 

MiraclePieCo is right, you don't need a shroud. Our trucks have a big radiator and a big grille - lots of air. That shroud is going to restrict air-flow thru the radiator and you're going to have cooling problems. These electric cooling fans are not full time, they turn on and off as needed. Yours will be on full time.

Re: Electric fan setup?
 

To each his own, I guess.

Around here, most custom cars/trucks have problems keeping the engine cool in stop and go traffic with the ambient ant 115F and the additional heat load of an AC condenser.

It really doesn't matter how big the frontal area of the truck is when it is stuck in traffic, because there's no ram air effect stagnating air in front of the radiator and creating pressure differential across the radiator- all that matters is the amount of airflow the fan can pull across the radiator. And it is just physics that a fan in a shroud (correctly designed) is more efficient than a fan just hanging in the airstream.

I can't recall a single production car I've seen in the last 20 years that didn't have a shroud to direct air through the radiator. Both electrical and mechanical fans seem to work, and anecdotally, it seems like there's a lot less overheating problems now than there was when I was a kid 50 years ago and these truck were commonplace. Engineering marches on.

It is your prerogative to run unshrouded like the fan in the pic of the previous post, but I'll stick with a shroud and a big fan where I can idle in stop and go traffic without overheating when it is 115F outside and 140F on the black asphalt. I'm resigned to sticking around this god-forsaken hell-hole in the summer, and I don't want the aggravation of overheating while enjoying my truck.

Best of luck with yours.

I've got to stop answering posts like these with a drink in my hand!

Re: Electric fan setup?
 

I had over heating problems with my truck with the new electric fan I put on. I didn't like it at all. I couldn't get all the switches, relays, thermostat and on/off plus the shroud I made (which did not work like I planed) wiring etc to work together. I decided to go back to the old flex fan I had before with new shroud design. This one worked really well. No more overheating problems. If you are interested in how I made it can be found in my build thread #333 thru 348. I went back to mechanical because there are way less things to worry about. Lotta work but well worth it to me.

Earl

Re: Electric fan setup?
 

I don't really care whether production cars today have shrouds. My truck will run just fine with no fan at all at normal road speeds. It does need the fan in traffic, stop and go stuff.

I'm guess I'm at a disadvantage here. Besides being a hot rodder for 65 years, I spent over 40 years involved in automotive powertrain development, mostly with GM. Included in that at one time was prepping prototype cars for climate wind tunnel testing at Harrison Division. Harrison made GM radiators.