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Discussion Starter · #1 ·
HI,
I have a 454 with an electric fan that is pulling 1600cfm. I have problems overheating on any hot day when stopped at a light or in stop and go traffic. I am going to get a new fan as I have a new 27x19 in summit radiator.
I want at least 4000cfm and there is only one aftermarket fan that i can find that puts that out. Its a derale dual fan with shroud and runs $265 at summit. My question is should I go that route or should I buy a Ford Taurus fan that puts out 4500 cfm and go that route?

anyone have any experience with either?

thanks,
david
 

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Discussion Starter · #3 ·
It is a 1963 chevy c10 with a 454 with about 500hp. It has a 292 isky cam with a .590 lift. its about 4800lbs and running a 1600 cfm flex lite electric fan right now. as long as there is airflow from me driving it does fine, but once i stop for a short period on a hot day it just starts to heat right up. On a 65 degree day its hard for it to get above 185 but on anything hotter than 80-85 then it just climbs like crazy at stops. I talked to summit racing and they said i need at least a 3000cfm fan and a shroud and the derale fan is the only thing they carry that fits my size radiator and is powerful enough.

I have a chrome alternator and not sure what the amps are on it since it has the chrome plating over it. I am worried if I get a taurus fan and it just eating up my electrical system due to the amps it needs. Im leaning towards the new derale fan since i think it will give me less trouble in the long run and requires less amps. I just dont have the extra money to get it and have been trying to find cheaper ways but something that will last in the long run and not just a short solution.

THanks,
david
 

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Never used an electric fan and never will. The bulletproof solution is a big block sized radiator, full shroud, 18 inch, 7-blade OEM steel fan, thermostatically controlled fan clutch and driving the whole mess off the water pump.

The very small gain that is realized using an electric system isn't worth the hassle to me. Either way, it takes power to turn the fan, whether it's electrical power made by the alternator which has to be turned by the crank or whether it's mechanical power off the water pump which has to be turned by the crank. In the end, it takes power off the crank either way to cool the motor.

I've been doing this stuff for over 50 years and have never had a problem with a properly engineered mechanical system. Many of my buddies have used electrical systems and I get to hear all the horror stories, just like yours.

Here's a link to a wiki article that may provide some pointers for you....
http://www.crankshaftcoalition.com/wiki/Bulletproof_cooling_system
 

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Discussion Starter · #5 ·
thanks tech for your response.
What would be the adiquite radiator size for my application? The reason why i have the size i do it that is the biggest that will fit without cutomizing it.

thanks
david
 

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Discussion Starter · #7 ·
so would a stainless steel 7 blade 18inch flex a light fan work? My only question on the mechanical fan is, If my heat problem comes when im idling, isnt that not going to work as well since my rpms will be the lowest then and therefore the fan will be spinning at the slowest it can?

thanks again,
david
 

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daveid said:
so would a stainless steel 7 blade 18inch flex a light fan work? My only question on the mechanical fan is, If my heat problem comes when im idling, isnt that not going to work as well since my rpms will be the lowest then and therefore the fan will be spinning at the slowest it can?

thanks again,
david
Above 30/35 MPH, you don't need a fan at all, so it's all about low rpm, low speed cooling. This is where an OEM-type system works best. It's about the diameter and pitch of the fan blades and a good shroud that fits close to the radiator core and completes a 360-degree circle around the fan blades, with the fan blades half-in and half-out of the shroud opening. Also, the fan blades need to be close-fitting to the shroud hole on the diameter. An 18-inch fan with a 19-20 inch shroud hole will work just fine. The shroud hole needs to be large enough so that the blades will not contact the shroud as the motor rocks laterally on the motor mounts, but not so big that the blades cannot pull a good vacuum between the blades and the radiator core.

It sounds like you're hung up on a flex fan. You don't need a flex fan with a fan clutch. You need a solid steel OEM 18-inch, 7-blade fan with a thermostatically-controlled fan clutch mounted on the front of the fan blades. (actually, the fan clutch mounts to the water pump and the fan mounts to the fan clutch). A good fan will have a pitch of around 2 1/4 to 2 1/2 inches. Lay the fan down flat on the floor and measure from the floor to the edge of any fan blade to find the pitch. I used a fan from an Olds diesel once when I was skeptical about being able to cool a high-compression motor in a tight engine bay. The pitch was 3 inches.

Also be cautious when choosing a fan for a conventional vee-belt drive application that turns the water pump in a clockwise direction as you're looking at the front of the motor. If you use a fan from a late-model application that uses a serpentine belt system and turns the water pump counter-clockwise, you'll be blowing air toward the front of the radiator. The pitch is reversed on those fans. You cannot turn a fan around to blow the other way, it won't work. A fan blade will only blow air one way, no matter which way you mount it, correctly or backwards. You must use the correct fan with the correct direction of pitch for the application you're building to. If you're using a conventional vee belt water pump that turns clockwise, then use a fan that was designed to work with a clockwise water pump. If you're using a serpentine belt water pump that turns counter-clockwise, then use a fan that was designed to work with a counter-clockwise water pump.

While I'm on this subject of fans and fan blades, I want to bulletproof it for everyone. I'm not very good at describing this without an illustration, but try to follow along.
You know how you hold a tire/wheel when you're mounting it onto an axle or hub? Hold the fan the same way and then move it down to the floor, with your head directly above the fan so that you're looking down on a blade. If the blade orientation is northwest/southeast, it's a conventional vee belt drive fan that is meant to rotate clockwise as you're looking at the front of the motor. If the blade orientation is southwest/northeast, it's a serpentine drive system fan that is meant to rotate counter-clockwise as you're looking at the front of the motor. Further, any fan can be mounted frontwards or backwards and will still work the same way, however one way it will be efficient and the other way it will be inefficient. Any fan blade needs to have the concave, hollowed-out side facing the motor, with the convex, rounded-out side (like a fat man's belly) facing the radiator.
 

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Tech and Vince do make some good points,, But I do have to disagree about the electric fans.. When they are set up right, there's no problem's..Sorry.. I'm not by all means trying to get in a pi**** contest.. But I have ran them with excellent results... Here in La we get days that hit well over 100* .. and 75% of the hot rods here run elec fans.. I just don't get the problem's some here had.. :confused: And yes at idle it is hooked up.. Not turning as slow as a reg fan...Tech and Vince if this p**** y'all off I'm sorry.. But this forum is about info.. Good and bad.. But just because yall don't like them don't make it wrong to run one..It can be done, and is still being done...Like I said.. I don't want anyone mad.. But I do Know first hand, That it does work well,, And I have ran them On some very hot big block's, and 100* + Days..The size of your rad is most important ...Good luck with what every you do..
 

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NEW INTERIORS said:
..Sorry.. I'm not by all means trying to get in a pi**** contest.....Tech and Vince if this p**** y'all off I'm sorry.. But this forum is about info.....Like I said.. I don't want anyone mad..
Hey dude, you'll never p*** me off voicing your opinion. I'll fight to the death for your right to say what you think, unlike some other narrow-minded people on this board..... :boxing:
There are those who like Chevys, there are those who like Fords and there are those who like other make cars/trucks. There are those who like mechanical systems and there are those who like electrical systems. That's what makes the world go 'round. If everyone was the same, it would be a very dull life.
 

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Discussion Starter · #13 ·
Thanks guys for all the info. Vince, I do not have a fan shroud and just started looking on where to find one. You know a good place to buy one?
Tech, I looked for a 7 blade steel fan but i kept coming up with a flex a lite stainless steal fan. Do you know a good place to buy the oem style ones?


Thanks,
david
 

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techinspector1 said:
Hey dude, you'll never p*** me off voicing your opinion. I'll fight to the death for your right to say what you think, unlike some other narrow-minded people on this board..... :boxing:
There are those who like Chevys, there are those who like Fords and there are those who like other make cars/trucks. There are those who like mechanical systems and there are those who like electrical systems. That's what makes the world go 'round. If everyone was the same, it would be a very dull life.
I do fully understand tech.. :thumbup: I'm glad you understand where I was coming from... Thanks.. ;)
 

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American Muscle said:
If there is enough space can a electric fan and mechanical fn be used at the same time?
Yeah, it's possible to do, but is not normally done. Choose one or the other and optimize it for your application. I've seen some fellows install an electric pusher fan in front of the radiator while using a mechanical system behind the radiator. Problem with that is, the pusher fan blocks the flow of air at higher vehicle speeds where you don't need a fan at all.
 

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daveid said:
Thanks guys for all the info. Vince, I do not have a fan shroud and just started looking on where to find one. You know a good place to buy one?
Tech, I looked for a 7 blade steel fan but i kept coming up with a flex a lite stainless steal fan. Do you know a good place to buy the oem style ones?
Thanks,
david
Any boneyard that has an old big block equipped car, station wagon or pickup truck (396/402/427/454). You can usually rescue the shroud if the motor is gone. If the motor is still there, you can also rescue the fan, fan clutch and any brackets you might need (AC, PS pump, alternator, etc). Tall deck 427/454 motors such as found in schoolbuses, dump trucks, etc may have different brackets, but the shroud/fan/clutch should work on your short deck motor. Early 70's Impala station wagons with a 402 used to be my favorite find.
 

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Some old Mercedes diesels used a little pusher " overheat " fan. I don't really know if they did anything in an overheat situation, but that is the only time they come on.. I'v got 1 and I jumped 12v to it, and it worked, but didn't seem to move much air.. this is also the only factory situation I know of using a Mech fan and a Electric fan
 
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