Thread: Electric Fan Help

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I have a 69 460 10.5:1 comp. that generates alot of heat.Would i be better off installing a electric fan and removing the clutch fan (which should generate more horses) or keep the clutch fan and install a pusher fan?Would I see a temp. drop with a pusher & clutch fan?My clutch fan moves alot of air.I can't see how those little electric fans could out perform the good ol' clutch. Thanks Guys............Dennis

I'm no fan of electric fans ( pun intended )

Have you thought where you free up horsepower if you remove a clutch fan ? Firstly they operate on engine temperature, they have a bimetal on the front of the clutch hub. As the air flow temperature rise the bimetal expands and the fan kicks in dragging air in through the radiator and shroud thus increasing airflow and bringing the water temp down. Now if we think about it when dont we have airflow ?, when the vehicle is stopped with the engine running and we are getting no ram effect of the vehcle moving along and pushing the air through the radiator. So underhood temps climb and the fan is going. Now the question to ask is how much horsepower do I have to generate while the car is sitting still ? awnser none because your not going anywhere while you wait for that big red stoplight. Once you start moving and the slipstream starts moving through the radiator again underhood temps drop and the clutch disengages and the fan windmills in the slipstream, so basicly no horsepower is being consumed.

To me a clutch fan is an excellent high performace design, it may not look light and pretty, but they do a great job.

A few more points to add onto dennys, is the radiator fins clear ? no debri like rubbish bags or dead ducks and insects blocking the fins. Is the fan belts tight ? Is the shroud on correctly or is it damaged. You see you can get a cooling problem from 2 things either it's a water flow problem or an air flow problem.

i took the thermostat out, the clutch fan is new, the radiator is new,the trans cooler is new, the shroud is intact.The hotter it is outside the hotter the engine temp.This is my 1st 10.5:1 460. i had 8 other low comp. 460's that ran cool.Is it normal for these engines to run a little hot?The gauge reads about 2 clock on the factory gauge on a 69 mark 3.The only thing i have not done is adjust the carb because it leaks from the jet.could this bring the temp. down if properly adjusted? I'm gonna get a Edelbrock intake and carb in the spring.Thanks for your replies.

My suggestion would be to install a mechanical temp gauge and see what the engine is actually running... Hi compression engines will run a bit higher, especially in traffic. I had a hauler with a 460 in it, ran at 200 degrees all the time.

Put the thermostat back in. It is an intregal part of the cooling system and actually serves as a restrictor plate to slow the coolant down to allow better heat transfer from the motor to the coolant and then from the coolant to the radiator.

What vehicle is this 460 in? '69 Lincoln? They should have come stock with a 10-1 compression big block. When does it get warm, only in traffic or going down the road too? How are you hoses? Especially the lower radiator hose, make sure they are not collapsing. Do you have a coolant recovery system, do you see the water level going up and down in the reservoir?

Pat

it seems to run hotter at higher speeds.Its fine at 45-55 but at 75- 80 it runs a little hot. i use 50 weight oil in the summer thanks

I have no resevoir bottlle but when i park the car after a ride in july the coolant seeps out from the over flow tube onto the street Thanks Guys P.s. the ignition timing is dead on

I agree with every thing so far, but on the timing deal how does it start after heat soak? If it starts right away then u have a cooling prob like air flow getting around the rad instead of thru it. Or with no thermo. the water is not slow enough. Motrcycle guys sometimes get their bikes cooler by dialing in more fuel whivh helps to quench some of the flame. And sometimes with fords u cant set the timing totally with a light. Hope this helps I have a many a big block rodeo, but I still go back for more. RDHOTFRD

Could be that your water channels in the engine block are full of crud,,,,,if it's not that,,then i'd be looking at the volumetric efficiency of the radiator you have in your vehicle.
An electric fan is not going to help you at 80mph,,,,,you should have sufficient cooling to do the job at that speed even without a fan.
I'd definately look at increasing your rad core number,,,,and give your engine block a realy good flush.

If, if, if it will clear put your electric fan or 2 smaller ones behind the rad to pull air and keep the stock fan. Putting it in front will actually block off flow. You can switch the electric on manually if you're stuck on traffic.

If you have a vehicle and don't know if or when the cooling system was last cleaned out by all means get the radiator rodded out and pressure tested and have the block flushed.

Really make sure your clutch fan is working...... They can be a total pain in the rear to figure out. I had a vehicle that for years gave me the same over heating problems.. FOR YEARS!! I had to drive to the temp gauge.... I changed the radiator. I changed the water pump. I changed thermostats 6 times!! The fan always turned, "obviously", it was working. Then in the middle of a hot trip in Oregan blahhh the fan failed! Took a few hours to go a few miles, pour water on radiator drive a mile... step and repeat to a motel. Walked down the street got a new clutch, oem replacement.... put it in in the hotel...(they weren't pleased)... and HOLY MACKEREL the heating problems left FOREVER...

I have done nothing more in 87K miles and it never, EVER, exceeds the thermostat temperature. That included a heavy 6,750 pound 4WD Suburban loaded to the gills, 4 people, in Death Valley, in the summer.

Right there I learned that a spinning clutch fan is NOT necessarily a functional clutch fan. If I ever have an overheating problem in a vehicle with a clutch fan again I will replace the clutch first!

The clutch can fail, essentially limiting the horsepower to the fan. Instead of maybe 6HP running the fan you may be getting only 3HP. But no one can look at a fan and perceive that difference. But to the cooling system that is the same as covering half your radiator with insulation.

Kcress,,has something there!!!
It's an easily overlooked problem,,,,,try swapping out the clutch fan with a new one,,,,or put a set of flex blades on her.

Yo DennyW you did indeed! I felt in further posts the clutch was getting the short shrift and is tough to test. There is one failure mode that is very tough to test. As in my fan's case the failure was not a failure to engage.... It was a failure to engage fully. My fan always made the appropriate roar when expected. It just was slipping while engaged. So while your test will detect it engaging/disengaging it may not show engaged-slipping. That's why sans some complex dynamic test system it may be easier to just change out the dang thing. For that vehicle, guessin 69 Lincoln, your talking $40.

I don't want to completely hijack this thread which is for Ford 460s with fairly high C.R., but what about a mild 350 SBC with 9:1 C.R.? Everyone tells me to use an electric fan, particularly at idle, but what about a flexfan? It's either/or since the electric fan does not leave room for a flex fan. What about a flex fan with a shroud for a mild 350 and a '29 replica "Cobra" fan? Can I use a flex fan with a small electric fan mounted high up on the radiator or is there just no room?

Don Shillady
Retired Scientist/teen rodder

Personally... I hate flex fans. They are only rpm controlled. This means they have no idea what the engine is doin workwise.

Examples:

Low gear hill climb: High rpm, hard work, lots of heat, flat fan = no air.

Long gradual freeway downhill: Low rpm, no heat, maximum fan = why?

Both electric and clutch fans deal with these types of situations because they are temperature controlled as fans should be.

Electric fans have a few drawbacks. They use a hell of a lot of electricity! 20 to 30 amps is not unusual. This is not a minor increase in a vehicles electrical budget. Often it requires eventual electrical system modifications. Often you soon discover any electrical system shortcomings. They often mount with strange radiator modifications, hanging the fans on things plunging into the very radiator cores. This creeps me out in the age of $700 radiators. On the upside they cool a lot at idle if needed, (helps the A/C). They can cut all fan related energy consumption at freeway speeds and in cold weather.

Clutches: They can allow a very large fan load if desired but shut down when not used. As mentioned they can fail in nasty subtle ways. They are a heavy item to rotate quickly.

If you want maximum reliability a solid fan is it. Big loud!

Next would be a clutch which drops the noise level and increases the gas mileage.

Electric when engine mods or other things preclude other methods.

Fiberglass... Sim pel, cheep.