Electric fan vs clutch

[coloradodave]

Part of the problem with buying an electric fan is that manufacturers "fudge" the cfm ratings. There is no way to compare one fan against another because there isn't an international standard that all the manufacturers test to. When I was doing research on this I talked to a few different companies that build fans and got the run around when I confronted them with a competitor's fan that looked identical, was the same amp motor, same diameter, same blade shape but literally pulled HALF the cfms. Simply put, they lie...
Oh, BTW Al (Hemi-itis) not all of us have that huge heat sink sitting on top of our engines to dissipate heat... Another advantage to a roots blower.

 

[HT413]

Go to the junkyard and grab some fans off a 90’s - 2000’s Maxima. They’ll fit and will cost next to nothing.

 

[LemonWedge]

Here’s what I’m currently looking at...
https://www.summitracing.com/parts/der-16822

This setup looks like it would fit my radiator like a glove, and claims a decent amount of cfm. Anybody have experience with this fan?

Also, still looking for experience with a adding a clutch like this to my current setup.
https://www.summitracing.com/parts/hda-2747

 

[33 IMP]

To the question in your first post; i'm not sure that the fans for a clutch application and fixed fans have the same bolt pattern, that may need some research. If the patterns are the same, you will likely save some hp.
I would look around in a self serve boneyard for a large electric fan from a 3/4 or 1ton truck, mine gets very little use in my truck, it seems that it will last forever.
If you are primarily using your car for bracket racing i would consider an electric water pump too. My 'tina uses a 18" oem fan, electric pump, with a homemade shroud, a relay, and a temp sensor that turns the fan and pump off or on according to temp, but still has a switch that i can turn it on manually.(i tended to leave them running in the pits then forget to turn them off after the engine was cool, and run the battery down)

 

[LemonWedge]

Hadn’t thought of that, but it would appear you are correct. A flex fan like mine doesn’t look like it will mount to a clutch. Just as well, I’ll just run it as it currently is until budget allows a nice electric setup. Thanks to all.

 

[HT413]

Hadn’t thought of that, but it would appear you are correct. A flex fan like mine doesn’t look like it will mount to a clutch. Just as well, I’ll just run it as it currently is until budget allows a nice electric setup. Thanks to all.

Fan clutches have the same bolt pattern as a solid mount fan because they both mount to the water pump.

A clutch fan has a wider bolt pattern because it doesn’t mount to the water pump; it mounts to that clutch fan. It’s wider because it has to pass over the about that mounts to water pump.

So yea

 

[cudatom]

Lemonwedge I'm in the same boat as you. Since I will be racing more and street driving less. I am removing my a fixed blade fan and switching to electric. I will also be going to a electric water pump. This will help me keep the water temp the same round to round.

The troubles always would happen when I go closer to the finals. With a mech pump and fixed blades I had no way to cool the engine down fast. The electric pump and fan will fix that.

 

[747mopar]

I use the same spal dual 11' fan also. With ac, it didn't move enough air at idle with the mechanical fan. I all so use the derale PWM fan controller.

Yeap, got the controller also.. not needed but nice having the adjustability.

 

[383man]

The factory style clutch fans have a thermal valve in them that lets the fluid go into the unit and drive the fan more as the eng heats up. I believe some aftermarket clutch fans just work by rpm and pull more air at low speeds but slip much more at higher rpm. To me a factory type and some aftermarket fans with the thermal valve will work good as long as your race car is not to hot when you leave the line. I don't remember what temp the clutch fans with the thermal valve are fully locked up as that's when they will rob the most power from your eng. But when not engaged when the eng is warming up they will give more hp and rob much less since they are slipping then. If you leave the line around 160 degrees it will depend on how much the clutch fan is engaged as to if it will rob much hp. You might want to look up when the clutch fan is fully engaged as I don't remember. The one you posted looks to have a thermal valve on it so it works by temp. I do remember on my Ramcharger when I would drive 3 hrs to the beach in the summer when I would come to a redlite and sit a few minutes on a 90 plus degree day the fan would engage at the lite because when I took off and got in third gear it sounded like I was still in second from the clutch fan engaged. But once I got rolling to 60 mph it only took a minute or two for the fan to disengage as I could hear it stop pulling. Ron

 

[LemonWedge]

Your point is very important to a bracket racer such as myself, Ron. I realized that a clutch-fan is a horrible choice for a bracket car where I am trying to make the car as consistent as possible, and predict what it is going to do. Once I thought about that, I quickly decided to wait and get a nice electric fan setup.

 

[Mike Gaines]

Your point is very important to a bracket racer such as myself, Ron. I realized that a clutch-fan is a horrible choice for a bracket car where I am trying to make the car as consistent as possible, and predict what it is going to do. Once I thought about that, I quickly decided to wait and get a nice electric fan setup.

As I have said above, I use an electric water pump (Meziere 53 gallon model, they make smaller ones) in combo with my Twin Spal Electric Fans and my Big BE COOL RADIATOR. When I come back to the pits, or back to the staging lanes, I turn off the motor, switch on the electric fans and water pump and the motor cools down to 110 degrees in about 15 minutes (if I am hot lapping it in late rounds of eliminations I can get it cooled down to at least 130 or 140 degrees in about 10 minutes).
I then use this setup when I am pulling up and stopping in the staging lanes when they are getting us to run because I like to pull into the water box and maximum of 135 degrees. When I come out of the water box and I am pulling up to the line the temperature has then risen to around 160 degrees. When I go thru the lights the temp is around 180 degrees and then goes on up to around 200 to 205 degrees coming back down the return road to pick up my time slip and go back to my pit or the staging lanes.

 

[383man]

Your point is very important to a bracket racer such as myself, Ron. I realized that a clutch-fan is a horrible choice for a bracket car where I am trying to make the car as consistent as possible, and predict what it is going to do. Once I thought about that, I quickly decided to wait and get a nice electric fan setup.

I understand what you mean but we also have to be sure our street/strip cars don't overheat. So in that respect a clutch fan is not a bad idea but if you race a lot you cant beat the electric fans and electric waterpump. Good luck , Ron

 

[66Satellite47]

Very good topic. Since I headed toward more strip use than street. "Back in the Day" on my bracket Coronet, I ran an electric drive WP with a plastic fan switched, worked good. On my Arrow two electric fans & electric WP drive. Having the switch ability to use the pump & fan sure is an advantage in my opinion. My clutch fan on the Satellite does work great though.

 

[BlooDSMeaR]

For the budget minded: I used a mid 90's ford Taurus fan and shroud for my 73 RR. It cost all of $10 bucks out of pick n' pull, and fit my radiator perfectly.

 

[Budnicks]

Did anyone even mention ?
the Hp pick up boost & the snappy/better throttle response too
(I know it's nominal but every little bit helps with a racecar or performance applications)
not using a mech. fan resistance & belt driven mech. pump ?
yes it may need more Amps from the Alternator, than a stock 48 amp
(I run a "chrome" 75 amp Powermaster)

I run a thicker 3 core 22" down flow custom alum. rad. from Mancini Racing
can't remember how much I paid & a 20#psi cap (all parts & prices are from 2005-ish)
remember the cap pressure is a big part of the cooling too

I'm running 1 - Perma-cool #prm-19115 - $157 Summit Racing
electric fans 1- 16" puller/Alum blade
(you can reverse/flip over the fan blades, to make it a pusher or puller)
rated at 2950cfm in a custom shroud, it moves some serous air
especially with the shroud
it's only appr. 3-1/8"-3-1/4" off the radiator...
It's one of the shallowest electric fans/fan motors, I found
with enough cfm to work properly, it's offset slightly to the
intake side of the rad./bottom hose side
I have very little clearance to have another fan or OE crap on the inside...

& 1- is a Prema-Cool #prm-19113 - $153 Summit Racing
1- 13" pusher/also has alum blade,
rated at 2600cfm (I see they are rated at 3000cfm now) in front of the rad.
slightly offset to the output top hose side of the rad.
for just in case if it gets hot 'in any scenario'
I'm not a big fan of the plastic blades, but that's just me...

(sorry the old photo sucks)

I also run an electric Pro-form 35-37gpm water-pump (was $190 Summit)
& I still had to restrict it's flow (of the water-pump)
(a 5/8" hole in a washer/made out of a piece of stainless steel,
inline where the thermostat normally would be)
so the water stays in the radiator long enough 'to actually cool it down',
& not just forced/flow thru it
mounted in a MoPar Perf. alum. w/p housing (sorry the old photos suck)

everything electrically is always ran thru 30 amp Boshe relays
(any electronics, electric motor or pump, all are always on a relay)
& I also have manual arming on/of toggle switches just in case

I refer it as a "Street-beast" sort of a drag car, in search of a corner...
I even still have a heater-core & hoses
It's driven on windy mountain roads & few beat runs, 1/4 mile etc.
It rarely gets over 190*, even in 100* Calif. summer dry/heat
& rarely ever need the 2nd pusher fan, but it's there, just in case...
(albeit pusher fan spins like crazy when It's going down the road I'm sure)

 

[66Satellite47]

I will say again, if you are a bracket racer, you need to run an electric drive water pump. My stock water pump with the 26" radiator did well. Late rounds need quicker cool down.

 

[BlooDSMeaR]

I will say again, if you are a bracket racer, you need to run an electric drive water pump. My stock water pump with the 26" radiator did well. Late rounds need quicker cool down.

Thats where the bags of ice on the radiator come into play

 

[Tex013]

its a bit like choice of beer , each to their own . As a bracket racer you should know your car and be able to dial accordingly . As a heads up racer , yes you want all of the power you can get . Depends if you have a dedicated race car or race your daily . I run a mechanical waterpump , Mopar 5 blade clutch fan and a 12" electric fan offset on the front of my radiator . I rarely need to worry about heat when racing , worst case it might go 190 but being judicious with running in the lanes helps . On the street even in peak hour over 100F the motor will only go 205-210 , once it gets moving down it comes .
I also like how a clutch fan rarely fails completely but electric can , same with waterpumps .
Here I , and others , have fitted Ford Falcon dual fan units with Davies Craig controllers . They are very effective with cooling all sizes of motors .

Tex

 

[LemonWedge]

The issue with bracket or index racing with a clutch-fan is that you can’t easily control when the fan is engaged vs free-clutched. Thus, depending on temperature, the parasitic loss will vary. The static mounted fan may rob you of more hp, but at least you can count on the same equation every time. When dialing or trying to hit an index, consistency is what you want.

 

[LemonWedge]

I will say again, if you are a bracket racer, you need to run an electric drive water pump. My stock water pump with the 26" radiator did well. Late rounds need quicker cool down.

Last year I got myself a good industrial fan to throw at the car between rounds. I was surprised how well it worked at cooling the car down in just 10 minutes or so. But late in races you’re typically going straight back to the staging lanes with little or no down time, so an electric pump would definitely work best in those situations.