Electric radiator fans?

[volare 77]

I would only do it if I needed to. If what I have is working for me then I leave it alone. My car doesn`t care what is keeping it cool. Why spend the money for no reason. For the street nobody is going to feel 5 hp. I`m not going to do it just for the cool factor(no pun intended). Sure belts have been lost. Maybe one in my lifetime. Usually I have a spare with me though. Seldom do I drive my car 100`s of miles at a time and I do keep a eye on the condition of the belts and hoses.
Now if it was a daily driver that I needed to depend on 100% and I was having issues then that would be different.

 

[Oldiron440]

Nobody who buys an electric fan setup will want to think they wasted their money.
No doubt a properly thought out and installed electric system will have marginal advantages over a stock system in good working order in extreme conditions.
To quote popular opinion on older Citroen cars; "It's a complex way to achieve not very much".

Roger.

We all have our opinions

 

[Rustyroger]

We all have our opinions

Of course we do, and I respect your right to be wrong if you so wish.

Roger.

 

[Oldiron440]

Of course we do, and I respect your right to be wrong if you so wish.

Roger.

Typical Chrysler owner to cheap to change a thing calling a 35 year old beatter a classic.

 

[BudW]

Cooling system changes (or no changes), cooling fan design (non-flex metal, flex fan, or fan clutch) and/or even going with electric fan motors will be debatable for decades to come (possibly).

Also, everyone’s response, so far, is correct as I see it (unless I missed a wrong response somewhere . . .).

I do ask that all participants here to be civil to each other. Stating facts and opinions is one thing. Please refrain from saying someone else is wrong for doing this or having that.


I have LOTS of opinions to things (possibly, a few, might even be correct . . .).


Vehicles have been using engine driven cooling fans until the FWD (Front Wheel Drive) car came out (for Chrysler, it was 1978). It is somewhat difficult to have an engine driven fan on a transverse engine. The first few designs of electric cooling fan motors that Chrysler used – were, well good for a short time before going “poof”. Personally, I think Chrysler used an HVAC blower motor, to turn a large fan blade and found out the motor just couldn’t take that much of a constant load. Moving a lot of air through a radiator is different than moving air though dash vents.

By the mid ‘80’s, the electric cooling fans were starting to last for long time and were physically smaller.

I might be wrong, but I don’t think anyone (domestically) is making a vehicle with an engine driven fan cooling system, now days. It might be because of overall exhaust emission output, it might because of CAFE guidelines (Corporate Automobile Fuel Efficiency), It could be for overall manufacturing costs – I don’t know exactly. The bottom line is factory’s have gotten away from engine driven fan systems.

Until the rollout of the Magnum engines (I got away from dealership at that time), Chrysler used three different cooling fans from ’60-’90. A stiff fan blade (my ’77 wagon came factory with a stiff 4 blade fan blade and no fan shroud), a flex fan blade (used for a couple of years) and a fan clutch (mostly two different clutch designs).

The (all metal design) flex fan works good for a few years – but caused a lot of problems after a few years of usage. Chrysler didn’t have a recall on them, but as techs, we were told to check any that came into shop for loose blades. If a loose blade was found, to replace it with a fan clutch – under warranty. If a car came in with a blade that came apart (ie fan through the hood, etc.) that Chrysler was going to pay for it. The later – I saw and fixed/worked on a lot of. The Chrysler design metal flex fan is nothin’ but trouble.

Unrelated, I also seen a lot of issues with aftermarket fiberglass flex fans - long term. Short term, I think they are fine, and I don’t know how to define short term vs. long term on fiberglass fan blades – but I have seen a lot of fiberglass blades with missing (fiberglass) pieces, which makes me wonder about balance, durability, longtivity, and so forth. I would think any “component” spinning at 2 to 5,000 RPM that is out of balance – will wreak havoc on water pump bearings . . . but what do I know. I'm not knocking aftermarket (fiberglass) fans other than I have some possible concerns (which might not be a concern) - but I WILL NOT use a Chrysler metal flex fan blade (not an issue on most FMJ's).

On fan clutches that Chrysler used, there is the thermo clutch – which only engages at a certain temperature and a (not sure of exact name) torque sensitive clutch that will not allow fan RPM to exceed a certain speed. What is interesting is both types of clutches do both aspects (the thermo clutch also has an RPM limit, and the RPM limited clutch is also thermo controlled). I think Chrysler calls it by the primary purpose of clutch, maybe.
The Late 60's there was a fan clutch that had no spring on front of it. It was RPM limiting clutch that was on full time.

Thermo clutch

RPM limited clutch - with thermos properties. Sometimes referred to a HD clutch.


When I first got my ’77 wagon, it sounded like a vacuum cleaner when engine got over 2500 RPM. I took off the 4-blade fixed fan blade (and spacer) and replaced with a 5-blade clutch fan (from an ’84 Gran Fury police engine). The car still doesn’t have a fan shroud on it (came from factory without one). The car no longer sounds like a vacuum cleaner above 2500 RPM and, the engine sounds quite healthy going from a dead stop to 60 MPH (still a 100% stock car, other than fan clutch) now.
That said, the temp gauge still runs on hot side (using either fan blade type) in the summer months – but that should be fixed once I replace the 18” with the 26” radiator.


NOW WITH ALL OF THAT SAID: of the engine driven fans, I highly prefer the thermo fan clutch design, and if a choice is given: the HD version.

Fan clutches can go bad and it is not an easy thing to diagnosis. A fan blade should not have more than ¼” (6.3mm) free play front to rear. After engine is hot and turned off, the fan blade should be rather difficult to spin in place. When engine is cold, the fan blade might have almost no resistance to spinning to a lot of resistance.

Also, on any fan clutch system, when vehicle is warming up – you will be able to tell when the thermo fan clutch engages for the engine fan will become noticeable by air flow and by noise.


When a car is traveling over 30 MPH (50 KPH) – there is enough air flow through the radiator that a fan (electrical or mechanical) is not needed.
It is those periods below 30 MPH that a fan is needed.


Once I convert my cars to (daily driven) fuel injection – I also plan to convert both cars to electric cooling fans as well. Less rotating mass, more room underhood, easier to access the big block oil filter (which is a pain – no matter what) and have te F.I. computer control the fans. I also plan on using "a factory" dual motor setup – so (single) fan motor and water pump won’t try to occupy the same space. Which fan motor(s) hasn’t been decided upon, yet – but several will fit with little to no modifications to 26” radiator.

By then, I will also have my electrical system upgraded as well (alternator, wiring harness (wire thickness), relays, etc.). Personally, I prefer to use the externally regulated alternator for a handful of reasons – but I will not say anything negative if others prefer to use the simpler internally regulated versions. Having a trunk mounted battery is also recommended for most people (especially for those with big blocks) – but that can be troublesome for those driving wagons.
BudW

 

[Justwondering]

BudW
Thanks for the indepth info.

My hand goes up with a question:
Why do you want to mount the battery in the trunk?
(Assuming I ever figure out how to stop the slow water leak into it when it rains..)

JW

 

[80mirada]

The battery is a sizable chunk of weight, and moving it to the trunk helps shift the weight balance closer to 50/50

 

[Oldiron440]

I think he has said he is trying to free up under hood space.

 

[80mirada]

That helps too, but the most common reason is to transfer weight to the rear.

 

[Oldiron440]

The thing I don't like about the battery in the rear is the hot wire from the rear of the car to the starter ( the best way) or the starter solenoid second choice.

 

[Poly]

That said, the temp gauge still runs on hot side (using either fan blade type) in the summer months – but that should be fixed once I replace the 18” with the 26” radiator.

Have you considered a shroud for the 18" Bud ? Of course the 26" offers an extra 8" width but the 18" might be a better arrangement in the # of cores. The list of different combos is long.
And the path of least resistance for the fan blade is to pull air from the space between the radiator and engine block(without a shroud).

 

[BudW]

I don’t have an overheating problem. The temp gauge rides on the higher side on the gauge, when it’s 110’ F (43’ C) in the shade and when in stop and go traffic. That is with a stock 318 2-bbl without A/C.

I should have mentioned that my plan is to convert car to A/C and to big block – which reason for is converting to the wider radiator. The 18-inch-wide radiator is fine for now but won’t be fine with big block (or with A/C).

One might exist – but I don’t recall remembering what an FMJ 18” fan shroud looks like – or even what it will take to find one. I have three 26” shrouds in my garage, currently.
At one time, I was considering finding a single electric cooling fan and mounting it inside of a factory 26” shroud – so it had the appearance of stock, but never got any further than that.


Justwonderng,
Car battery are dense and heavy. Having that "ballast" in trunk is best place for it, because:
- Front/Rear weight distribution
- For easier access to underhood components (big block oil filter access is great example)
- To keep the battery at a more constant temperature. Battery’s (of any kind) don’t like heat. It can get rather hot under a hood after a shutdown.

The down side to trunk mounted battery are:
– need to vent the battery outside.
- Need to run larger and longer cables to engine (starter and ground)
- It limits trunk space (which is not a problem for most of us).
- It looks tacky for a station wagon (being exposed – for the world to see)
- Makes jumpstarting (either direction) a bit more troublesome.
BudW

 

[XfbodyX]

I myself never found my 440 f body car with the battery in the oem spot cumbersome at all, not even my old 440 dart presented a problem with the front battery.

The ones I do have moved is just for weight and it keeps the high heat off them.

 

[SixBanger]

By then, I will also have my electrical system upgraded as well (alternator, wiring harness (wire thickness), relays, etc.). Personally, I prefer to use the externally regulated alternator for a handful of reasons – but I will not say anything negative if others prefer to use the simpler internally regulated versions. Having a trunk mounted battery is also recommended for most people (especially for those with big blocks) – but that can be troublesome for those driving wagons.

I think it is possible to add an capacitor to the electric system to prevent high load peak of turning on the fans. Only starting fans cause peak current duo to inertia mass etc. For 14" fans I see an continue current of 7 amp. Peak should be higher without capacitor, 2-3 times ish.

 

[89.Fifth]

I think it is possible to add an capitor to the elektric system to prevent high load peak of turning on the fans. Only starting fans cause peak current duo to mass interia etc. For 14" fans I see an continue currwnt of 7 amp. Peak should be higher without capitor, 2-3 times ish.

Good idea. Do you have a schematic of what adding a cap would look like?

 

[Poly]

I don’t have an overheating problem. The temp gauge rides on the higher side on the gauge, when it’s 110’ F (43’ C) in the shade and when in stop and go traffic. That is with a stock 318 2-bbl without A/C.

I should have mentioned that my plan is to convert car to A/C and to big block – which reason for is converting to the wider radiator. The 18-inch-wide radiator is fine for now but won’t be fine with big block (or with A/C).

110 in the shade is definitely getting toasty. I'll be looking forward to your build if you have a thread on it.

 

[SixBanger]

89.Fifth. I take a look on the web. Couldn't find an good electric scheme for cooling an car radiator. But it should be the same as for other aplications. The link shows how the circuit would work. "A small capacitor accross the motor will reduce the speed of the possibly fast voltage transitions, which causes less radiation and limits the dV/dt the transistor is subjected to"

Purpose of the diode and capacitor in this motor circuit

Or for 220/110 ac aplications, duo to 90 deg phase shifting. https://www.quora.com/Why-is-a-capacitor-used-in-a-fan

I don't have dig in the electric fan system to much. But I have seen this on an standalone cooling system on work. So that should be an AC fan instead of DC. Maybe this could give you some ideas.

 

[XfbodyX]

Why not just use two fans or possibly one better suited for the job, a capacitor just ads more to the loop and more parts to fail.

I think the more you research the less appealing the idea will be for a rad cooling fan fix.

 

[SixBanger]

Drive today for long time on the highway. But now with cold weather, its getting some colder in the car. Cooling level is oké, and the fan doesn't have an thermoclutch. But the lpg evaporator also absorbs heat from the cooling system. For converting lpg to gas takes ish 140 kWh (10 kg/h).
So an electric controlled cooling system can also improve performance of converting lpg to gas and heating the passenger space.
So only thing is to think of an rigid system. I will start an topic soon.

 

[Duke5A]

Dropbox - Electric Fan 26in Radiator.pdf

There is the link to the write up I followed for my fan and radiator setup. It was originally done by a member over on Moparts. I'm posting this to give you and idea of wiring. I'm not recommending this setup because by the time you're done you'll be $600 USD into it and that's without all those crazy taxes you have on top of that. This setup is more for a hot V8. You can get by with a single fan that fits you're radiator (I'm unsure of what size you're fan is). Dual speed setups are nice because they cut down on the noise level.

Use a controller that takes temperature input from a sensor that threads into the coolant flow somewhere. Those ones that just have a probe you stick into the radiator are crap.

One last thing though, if you're doing these upgrades simply trying to get some kind of return in fuel savings you're never going to see it. If it's a project you're undertaking just because you like to tinker then that's another story.