I'm looking for input on electric fans for our b-body's. I have a big horsepower Indy 572 Hemi in a '68 Charger. I'd like a double fan with shroud but after cruising all the likely websites haven't found any I liked. I need a shallow depth of less than 3 inches, or have considered a pusher fan, lotsa room up front. Car will see street and strip activity. My radiator is a 26 inch wide, top and bottom tank aluminum. Similar in fit to a stock piece. quality fans with quality shroud. Ideas??? Thanks

for what it's worth, i'm not a fan [i know, poor joke] of pusher fans because they have a tendency to block airflow in a normal, going down the interstate cruise situation. they may be a band-aid for when stuck in traffic, but that's about it. since your car is not stock, and you have minimal clearance in front of the engine but lots in front of the core support, if you can't find something to fit where you want, i would consider modifying the core support to move your radiator to the other side of the support to gain the couple of inches needed for a puller fan assembly. maybe not the answer you wanted, but certainly not a hard or difficult job to accomplish, even though you are already painted up nice. also, make sure your electrical system is upgraded to support the needed amperage draw a good fan system requires. just my opinion of course. your results may vary......

very nice charger by the way ! mine will never be that nice.....

Technically, doesn't a pusher and a puller fan block a radiator the exact same amount, but the difference is in the turbulence caused by the electric fan the real issue on which side its located?

Your depth is going to limit you. The higher CFM fans typically have thicker motors. A pair of staggerd 12 inch fans mounted to a custom shroud may get you there. We just shoehorned a pair into a 70 GTX with a 440 and a serpentine setup. I like Spal and Flexalite fans.

If going electric you MUST get fans that pull heavy amperage.

Forget CFM. That is an unregulated number. They can hang a fan from the rafters in a gymnasium and say it flows 50,000 cfm. Then, you get it home and it barely moves 300 cfm with a radiator in front of it.

The only way to see how much work it will do is to look at the amperage. Do not consider anything under 30 amps. Expect to see 60+ amps on startup.

Those monster Mercedes fans we played with may not fit in the room you have. Even with the soft start feature they would draw over 60 amps on start and pulled 50 amps while running.

Look for OE paired fans that are split. You may be able to squeeze them into your engine compartment.

If it's on the shelf at Pep Boys, Autozone, O'reilly, etc then don't bother. Walk right on by.

Again, avoid pushers if at all possible. I ran multiple tests and found that they always blocked air on the highway.

Did you use a premade shroud? or make your own? I planned on using twin puller fans if I can find a shroud that works. So that will give me allot of clearance being offset from the pulley at center.

Im not a fan, lol, either of pushers. But haven't had much luck find a shroud that worked for me with the limited space available. Which one wouldn't think would be hard to find in the first place. I'm not the first guy to do this by any means, lol. And thanks, she did turn out pretty nice!! If I do say so myself

"If going electric you MUST get fans that pull heavy amperage. "

Wish this had been from another source here, because its always a rock throwing contest, BUT I believe it is so misleading by omission, that it should be disputed. I can give a bunch of analogy's, but the number one measurement of a fan's effectiveness is how much mass of air it moves evenly, thru your installed radiator, amperage alone is a poor, and not a direct factor, in measuring that task.

It's all about your combination. New cars have electric fans but their job is to cool at low speeds or stop & go traffic. All aftermarket manufacturers claim a CFM but that's an unrestricted flow rating. Look at it this way. If an electric fan pulls X CFM, that flow would also be equal to the flow at X MPH. Once you exceed that X MPH, the constant speed fan is useless. Now the flow needed has to be greater than the restriction of the fan body and the shroud.
I started with thin flat shroud that had about 1-2 inches between the shroud and the radiator core which was too close. The shroud had some openings with small rubber flaps to allow excess air to pass but were to small to make a difference. I had two 10" fans (22x18" radiator) that were the highest advertised CFM I could find. Obviously, at speed the combination became a big restriction. All the air had to funnel its way through the two 10" holes with fans in them and with only 1-2 inches clearance between the shroud and core. I finally got it right, lesson learned. Would that setup work on a different car, absolutly.
Sorry about the long winded post. Congratulations to the guys that got it right the first time and good luck to you.

A few more pics of the car from Mopars in the Park last month.

so what did you wind up using? I can see the argument from both points for amp and cfm, so yes I agree it's a "right combination" issue.

I used the mercedes fan in my 67 Coronet and it works great with the champion 3 core rad. But it is a very tight fit. A member here sells the controller so there is a nice soft start plus it only runs hard when it needs to. I'm also using a gm 140 amp alt. which handles the additional amperage. I have A/C and a high horsepower 493 and my car stays nice and cool.

Do a search here on moparts and you should be able to find all the info you need to install it.

Ford contour dual fan set up.

We made the shroud as there was nothing available.
As far as the Amperage vs CFM comment, There is some validity to the comment, However, a high amp fan motor with a poorly designed blade will draw the amperage but not move the air.
An efficiently designed fan and motor will move the air while drawing minimal amperage. The trick is to find a supplier that does not "FLUFF" their numbers. Again, I like Spal and Flexalite.

Welcome to the world of Cooling

What about an oem fan setup from a later model vehicle? My brother ended up getting a used electric fan off a supercharged Pontiac Bonneville (iirc) in the wrecking yard for his Oldsmobile steet/strip car. The setup has two small individual fans side by side with built-in shrouds over each one and is pretty slim. The engine is on the verge of being not streetable (11.7 compression, and a hefty solid roller cam) and this junkyard fan setup handles it with ease.

The Mercedes fan like Feets recommended, Lincoln Mark 8, 4.6L Thunderbird, HHR, all good candidates for fans.

" Look at it this way. If an electric fan pulls X CFM, that flow would also be equal to the flow at X MPH. Once you exceed that X MPH, the constant speed fan is useless. Now the flow needed has to be greater than the restriction of the fan body and the shroud. "

If you are assuming the the electric fan does not have forward facing into the airstream intake, because if it does, the cfm will be higher then the cfm at standstill.

yes, i think i didn't explain correctly. both fans [if identical] will move the same amount of air. however, most cooling systems, if in good working condition, do not need a fan at "x" speed because the airflow through the core is enough to cool the radiator. this applies to mechanical and electric fans both. where the pusher fan creates a problem, is the fan and brackets block this air flow through the core by the amount of area the fan system takes up. a puller, by contrast does not because the full square inch area occupied by the fan system is behind the core, and the airflow through the grille opening to the core is as much as it can be [or is designed for]. where the majority of turbulence comes into play is when a pusher fan is used with a puller [of either type]. i "think" each type kind of work against each other even though the fan blades are designed to make the air flow toward the engine. not saying a pusher system won't work, but i really haven't seen an aftermarket setup that impresses me. and if using a mechanical fan and a pusher "just in case", i would rethink the whole system, including fan, water pump, radiator, and definitely use a shroud. without seeing the OP,s setup in person, i really can't offer a solution, but i think a pusher fan setup is not going to be it. remember, just my opinion.

What radiator, and how much clearance from radiator to water pump pulley?
Are you running A/C too?
I just changed my Coronet from a Champion 4-core with Ford contour fans to a slightly thinner Griffin dual 1.25" core radiator with dual 13" Spal puller fans that are the "thin" 2" design for clearance these are rated at 1,250 cfm and 10-amps each. They are actually from Be Cool #75039, which had a rebate when I bought them and they come with mounting hardware which is an extra cost if ordering from Spal. If you have the clearance, the standard thickness (3.4") fan will pull more air (1,710 cfm.)
The fans are mounted diagonal across the radiator and cover most the radiator.
I made this change over the winter, and I don't have the suspension finished on the car to tell how these changes work.
I also have A/C and I may mount a 17" pusher in front of the A/C condenser wired to only come on with the A/C?

Not much help here sense you already have a radiator, and if you stay with the twin fan idea.

I'll just show my combo for the single fan idea.

70 RR 475" Hemi, ported Stage V, small roller cam.
26" Glen Ray with Max Cooling core.
Mercedes "Monster" fan.
Roughly 2800 miles on the combo.

I wanted a close to stock look with better than stock cooling. hooziewhatsit's controller decides what fan speed is needed.







I shaved & also cut through the shroud flange to get more clearance from the pump pulley. Used some sticky backed felt where the shroud touches the core,...might sound be a little thicker felt. Also cut the pulley bolt heads down & the shaft too, to be able to get a belt through with a small pry.

But, so far haven't been able to pull the Fan/Shroud without pulling the Rad, because of the inlet nipple.

PS: I should've left the most outer flange (in that next to the last pic) on the shroud for better cosmetics,... & strength.

I use the electric fan/shroud setup from a '03 Viper on my cuda. Pretty cheap if you have a friend at a dealership get it for you w/ their discount. It has 2 speeds...I just use the lower speed setting. Cools my hemi good.
I do have a big Griffin radiator that does a real good job too.

True about a poorly designed fan drawing excessive amperage.

The OEM fans all draw fairly high current because of their capacity. There's no free lunch. Hard work requires hard effort.

The Mercedes fan shown above is by far the most powerful I've dealt with and is a really nice fit on our factory radiators. It spikes over 60 amps on soft startup and pulls more than 50 amps at full speed. Lower speeds obviously pull less amperage.

Spal makes good stuff. I've used their fans. Flexalite is hit and miss. Their low priced fans are too weak for primary cooling.

What's the part #, application & pricing on that Mercedes fan?

The radiator is a significant obstruction to air flow. A properly set up car will control the air well enough to shove it through the radiator at speed. It will reach a limit and begin to spill out around the front of the car.

The reason you see chin spoilers under and behind front bumpers is to create a low pressure area in the engine compartment. That helps draw the air through the radiator.

A pusher fan has to be crazy strong. It is hanging out in front of the radiator where air flow is highest. If the fan isn't capable of moving air as fast as the natural flow it will become an obstruction.

I have tested this myself. A pair of typical parts house fans, when installed in a pusher location, caused higher engine temperatures when powered up. The engine cooled back down when the fans were turned off. Various speeds were tried. At 45 mph and above the engine heat increased.

Putting the fan behind the radiator gives it a lower velocity and lower volume air flow to deal with. Powerful fans perform well in this position.

Shrouds are just as critical with electrics as they are with mechanical fans. In one pair of tightly shrouded puller electrics I experienced heating problems at speed. I cut openings in the shroud and made flaps that were slightly larger than the openings. The fans would draw them closed at low speeds and the natural air flow would blow them open at speed.

Mercedes C230 through C320 from 2001 to 2006.

Aftermarket fans will require Hooziewhatsits controller (in the Moparts Products section). A direct 12 V line will burn them out quickly. Some factory fans can take a direct power input without a controller but that makes them run at insane speeds full time.
Factory fans are quite expensive.

We went through great lengths to test factory Mercedes vehicles and find out what kind of signal they used to power the fans.

100%

The OP's comment about I need a shallow depth of less than 3 inches
Led me to post what I did. I am Ass-uming the Mercedes fan, nor any of the other OEM suggestions will meet his space requirements. Maybe I am wrong and mis-informed but to my knowledge, Efficient OEM fans require both amperage and space. The space is usually the issue in my experience.
When Space is lacking creativity, IE: custom build is required. Again, correct me if I'm wrong.

Expensive,... IF, looking for new & OEM.

Had a friend in the local Dodge dealership try'n get me one for cost from the closest Mercedes dealer & the Mercedes parts guy wouldn't cut any slack on it. Don't remember for sure but think it was in the $550-650 range,...been a bit to long ago!

Had to dig back 3 yrs for the receipt on the new one I found on the net at Autotech in Nashville, Tn. $489.97 ymmv. Think I paid high 300's for the twin 12" spal's 15 yrs ago.

P/N A203 500 16 93 was the type shroud i liked.



PS: My fan motor ended up being 3&5/16" from the core.

I got lucky and found mine at a junkyard for $100. Check out car-parts.com

I would,ve done that also, if I was working on one of my other "gear head" projects,...but this one,s a bit different, with most everything new on it.

I do need to measure from core to shortened pump shaft for this thread.

I went out and measured one of the mercedes fans I have in the garage. It was 3.25-3.5". It also wasn't mounted to a radiator, so there may have been some tricks to shave off some height.

I've also tested the controller with a couple aftermarket fans, and it works just fine.

I measured my mercedes fan and got 3.125" I did have to use shorter allen head bolts to mount the water pump pulley.