Droshki

So, basically because it is ugly and clutters up the engine compartment, I am thinking of removing the clutch fan and its HUGE shroud and replacing with an electric fan while I do my engine swap in my `76. While you're in there, right?

I'm sure that Im not the first to do this and I will get considerable opinions.

What CFM do I need to look for, and is a shroud as big an issue with an electric fan? I read somewhere recently that a lot of this is kind of moot, as the original clutch fan only provides cooling when stopped or at slow speeds, because at any appreciable speeds it cuts out and airflow thru the radiator is sufficient alone to cool the engine.

Let's hear it-

Photos , prices, and sources welcome!


Oh and the goofy ram air looking thing that comes over the top of the radiator- I suppose at one point it was connected to the stock air cleaner. Not much stock under the hood anymore. Is it worth keeping for ducting cool outside air into the engine compartment? Or would I be better off blocking off this area to promote all air coming in the front of the car to pass through the radiator?

Durango_Boy

Electric is a good way to upgrade but it can also lead to more cooling problems if not done right. First is you need a large fan with...it's own integrated shroud. They are VERY important.

Two single fans to look for at ANY salvage yard.

Lincoln Mark VIII fan. Large diameter blades, shroud, VERY powerful motor and moves a lot of air. Custom, but a good fit.

Ford Taurus fan. These are the same motor so very powerful but the fan is 1" smaller diameter, and the shroud is a much better fit for the C3 radiator. It covers almost the whole radiator face.

Of those two, the Taurus fan is a better deal in my opinion.

You can use a T-stat in the intake manifold to control it's operation so it only comes on when the engine is hot.



I installed a set of Ford Focus fans. Dual fans, one constant, one switched, for very effective cooling. A tight fit but it works and I probably have 4000+ CFM when both are running.



I can help you find any one of them if you need assistance.

Also, if you're going to electric fans, seriously consider upgrading the charging system to a more powerful SI alternator or even better upgrading to a more modern 100 amp CS alternator.

http://photos.imageevent.com/durango...%20Install.pdf

Droshki

Nice response DB. Thank you.

The thought of buying anything except from Jegs/Summit didn't occur to me. Probably because I wouldn't have had a clue of what kind of donor car to look for. I think the Taurus sounds great, because I'm not looking for any more problems here. A simple installation would be nice. Do you have idea how many "while you're in there" projects are spawned while the motor is out? Damn good thing I'm not married

I will have to check with the local junkyard. What do you suppose a reasonable price to pay is? I'm good on the wiring, (thats actually my background) but that's an excellent suggestion with the thermal switch. I am going to get a prefab relay and harness just because they make it nice and neat. I will add an override switch in the cockpit next to my electric fuel pump switch, just in case.

Thank you also for the alternator link. I will have to consider seriously that upgrade too, but I think I'll wait on that until later. That's something that will be easy to do later after I get the new motor all in/tuned/bugs worked out.

I suppose if I wanted to get clever I could rig it to come on when the A/C is engaged too, but that will be so rare. I almost always have the tops out of my cars here in Florida, except for the dead of winter. The only reason I am even making the A/C functional on this car, is that you can actually reach things with the motor and headers out of the way. It seems impossible to tackle that VIR otherwise, unless you're double jointed. It was a breeze standing in the engine compartment to do it

PS I notice you have specced 185/165 on/off. How do you think that will go, I had planned on running a 180* engine thermostat. Think I should drop to 170? I know there is a lot of debate on this subject. FYI motor will be roots blown 383.

Duke94

I installed a Flex-a-lite low profile dual fan on my 78'. Works great. It covers up the entire rad so all the air pretty much goes through the rad. I kept the stock cool air inlet ducting.

curtis74

That's what I got as well. It only give me some problems in high outside temps in the summer when I'm at low speeds. Other than that it's a clean fit.

Frankenvette

I purchased a used electric fan for about $45.00, a Painless Wiring harness from Summit for around $50.00 and made my own mount from flat and angle aluminum purchased from my local hardware store. On the dyno I picked up about 15hp and 13 ft-lbs of torque.

Jim

SteveG75

Dual Spal fans.

Both wired to the same temp sensor. 195 on, 185 off. I run a 180 thermostat and the fans never run above 30 mph (even if it is 100 degrees out) and only cycle in traffic.

IMHO, there is no need to run an electric fan constantly. Above 30 mph, airflow will keep the car cool (that is why the clutch fan basically disconnects at speed, the fan is moving faster than the hub).

If you have AC, you can add a third relay controlled by the high pressure switch to turn the fan on when the AC is on. That will ensure good AC in stop and go traffic.

270

When the ZZ383 went in my '76 so did "Be Cool" radiator and dual electric fans and a "Painless Wiring" kit. Works great.

baxsom

what type of custom fabrication is required to mount the single fan and shroud (like the taurus) to the radiator. any specific year taurus fan

Durango_Boy

The Taurus fan has it's own quite large shroud so almost no fabrication is required except a way to attach the fan to the core support. Usually custom upper and lower brackets are needed but that's just anything your heart desires and can be fun designing.

I bought an almost new Taurus fan off of Ebay for $25 a few years ago and I think you can get them in salvage yards all day long for about that amount. Just make sure the blades spin without making a grinding noise. If the hoods sit open and the fan gets weather it can be prone to issues.

The 170 T-stat wouldn't be a bad thing in my eye at all so long as you weren't using it to fix a cooling problem...which it wouldn't do. To me it just allows the fluid to flow faster and 170 is a safe temp for that.

I too installed a manual override switch on my constant fan so I can work with the IGN on and not worry about the fan draining the battery.

...Roger...

I am not a fan of the electric fan setups because IMO it is a step down from reliability and maximum cooling that can be achieved from a really good clutch and 7 blade fan.
That said and because you said your doing this to clean up under the hood I would agree with Steve that the fans should be such that they don't have to come on (most of the time) while driving above 30.In other words the fans and shrouding should not restrict free air flow through the radiator.

Droshki

Good replies guys, thanks, keep it up.

I am not looking to do much custom fab. Like I said, "while I'm in there" has already turned into heater core repacement, VIR replacement, suspension rebuild, new calipers and pads, valve spring upgrade, and new headers and sidepipes. (I'd like some AFRs too but I checked my stocking, and Santa does not seem to be forthcoming on this issue, I guess I was naughty this year.)

I understand what you are saying DB. I'm not trying to fix a overheat problem, I had great temps with my 355 in there. I am just thinking 383 = more horsepowe = more heat. I've already bought a 180*, but was second guessing this for this reason. Pretty much I think the blower has to be removed to change the thermostat (snout too close to it) so I would rather not have to reattack this later after it's together.

Specific years on the Tauras to look for? The price seems great, given the cost of aftermarket fans. They seem to go form about $90 to "are-you-kidding-me?"

Anybody have price/specs/photo/part number on the Flex-a-lite low profile dual fan ?

More thoughts on the "cool air inlet ducting"?

Stop and go traffic not much of an issue in Panama City Beach unless you are on front beach road during spring break trying to show off for the bikini clad co-eds-ooops I am guilty of that

...Roger...

Not sure if anyone brought up the possible alternator upgrade you might need.Matt can give you info on that.

Durango_Boy

Thanks Roger. Yeah I posted that information at the bottom of my first post.

I'm not really sure what years, but anything from 1990 and up, maybe disregarding the 500 / Taurus, should be what you're looking for.

baxsom

ebay is selling 90-95 fan and shrouds foor about 90 bucks.
will those work

Durango_Boy

Yeah they work but imagine the high mileage on those fans, unless they are new...then go for it.

SanDiegoPaul

Hmmm. Reliability issues? Not if you buy quality stuff. I put the motor in my '76 several years ago...like six. Brand new copper/brass radiator at the same time.

When I made the swap to electric fans, I went the dual Spal fan route and used the original brackets from my shroud, to hold them on to the radiator. That was four years ago and there's been absolutely NO reliability issue at all.

Droshki

What did this cost? Pictures please? How did you use the original brackets? Did they come with a shroud? Did you keep the cool air inlet duct thingamabob?

Inquiring minds want to know!

couperdecar

15 hp ! Our clutch fans are eating up 15hp ! Anybody else do a before and after dyno? I thought the fan would eat "maybe" a couple horse. If a fan is using that much horse - it might be time for an upgrade.

...Roger...

Here is a link to discussion on the subject.If you do a search using the words "no free lunch" there are several threads with some testing.
http://forums.corvetteforum.com/c3-t...ater-pump.html