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My ‘69 350 4spd coupe as purchased has the engine mounted fan and the pictured radiator mounted fan that is currently wired hot off the alternator with a console switch. I don’t like manually switching the fan on/off. As it is now, it cools fine. No problems other than I think it looks dumb with 2 fans and possibly forgetting to turn fan on especially if someone is driving my car.
My question is do I need the engine mounted fan on a Tennessee car? Any suggestions on electric fan operation? Ignition only, ignition with thermostat, or just thermostat?
Thank you in advance.
Last edited by greg37027; Dec 28, 2021 at 12:37 AM.
Just an opinion..and welcome..
but post up details..year, engine, tranny, any issues etc..what radiator u have..
i think you need shrouding in either direction you go…others are more knowledgeable..
post pics of how wired in..not a fan …..of flex fans..do you have any of the original parts like fan and clutc and shrouding?
edit i see its a 69..you also need bushings in a arm..post up lots of pics! Especially how wired near alternator
Spal sells a proper wiring kit with 2 choices of on/off temp for 40ish give/take
If you put a shroud on the mech fan you should never have a heat issue
With no shroud that flex fan is doing little to no cooling. The kit for the electric is sold by Jegs and Summit
Once s yr I like to flush the fins out with a garden hose from the backside of course. Makes a huge difference in airflow
With no shroud that engine fan is not doing much of anything except making noise. The flex fans are also known to come apart at higher rpms. I would ditch that fan. The one mounted on the radiator is better but still has no shrouding around it. They do sell kits that run the fans off a thermostat so they go on only when the temps hit a range than back off at a lower temp. Pretty easy to wire in also.
The stock style fan, with proper sealings on the radiator, and a factory shroud is more than adequate......worked on millions of cars. No need to re-invent.
The stock style fan, with proper sealings on the radiator, and a factory shroud is more than adequate......worked on millions of cars. No need to re-invent.
I agree on this but he has none of those parts. No stock fan, no stock shroud ,no stock radiator so a stock fan shroud will not work in his case nor does he have the thermostatic fan drive. His cost to replace all that is going to be quite high. The stock system works well if you have all good parts.
Ditch the salad cutter and fine a dual fan setup with shroud.......that fan in its current state is doing nothing but making noise.....
Vette's need a shroud for airflow along the whole radiator rather than a 14" circle........
As stated, the OP is effectively starting from scratch. Starting from a working stock system, I converted to a dual-Spal electric fan setup for about $400- total. I also have the tools, background, and interest in electronics, so this was a fun project for me. YMMV.
There are advantages to both systems. Removing the spinning death wheel and making room for a strut brace were reasons enough for me to switch to electric fans. Depending on the car's application, the OP may also see a significant HP savings in the useful range of engine RPM.
A local member here in Florida has a 69 with a 383. He removed the stock fan when he put aluminum radiator & electric fans in. He said he found that most of the air was moving UNDER the engine, and the top of the engine bay was getting VERY hot. So he re-installed a mechanical fan. It doesn`t help much with cooling.... but it DOES move air across the top of the engine bay & out the side vents as intended. I did the same on my 71... I`ll keep the stock mechanical fan in addition to the twin 12" electric fans.
the C5 fann setup works good and is cheap and easy to find. right size for our cars. and oem stuff is designed to last. aftermarket stuff is designed to get you to buy it...
Yes,
1.But NOT that fan...flex fans SUCK.
2.Additionally, someone mounted an electric fan totally improperly, without a air gap plenum. (nor ram-air, at-speed flappers. which Chevy actually provides for. 30% of the cooling flow is BYPASSING the fan.
3. Someone has been throwing 'I give up' bandaids at this car...they removed the fan clutch!
4.Someone made a half-assed ATTEMPT at gasketing the radiator but FORGOT the entire section across the top of the radiator core support. So that's another 25% of available cooling air BYPASSING the radiator. Let alone what we can't see in the photo.
5. Someone REMOVED the FAN SHROUD, so the fan is mostly INEFFECTIVE ANYWAY. (extremely effective at pouring mixed hot air into the open element air cleaner!)
I'm saving this picture of 'WHAT NOT TO DO'
I have a 69 4 spd L-46...which does PERFECTLY WELL in blazing hot Phoenix Arizona....here is the formula;
1.CHEVY big block 7 bladed fan.
2.CHEVY big block 180 degree (early lock up) fan clutch.
3. Chevy fan shroud. STOCK RADIATOR,
4. 180 degree thermostat.
5. Spring in the lower radiator hose.
6. Foam surrounds (super anally) all around the radiator. EVERY molecule of air HAS TO go through the CORE of the radiator!!!!!
You cannot overheat my car even at 115 degrees.
As an Aerothermodynamic Engineer...all I see is horrorshow!
Cant help but wonder if (as one poster said) he may have a timing/tuning issue causing warmer temps. Many overlook that
I like the idea of having both types on there so if a belt or the electric fan fails you are still getting home.
OEM fans are probably the most reliable out there, need to look into that myself.
I run the stock mechanical fan set up on my ‘69 with a 396 sbc and vintage air with no overheating issues. I would return this car to the oem set up with the proper fan and shroud.
I like the C5 idea but I will also look into the spal options. Does the C5 dual fan and shroud set up have the thermostat internally installed
or is there additional wiring needed?/
I don't have any cooling issues or I wouldn't be wanting to lose the flex fan. I think it looks ridiculous to have 2 different fan systems and would
like to lose the spinning death wheel and have the ability to lower temperature once the engine is shut off (without it running and draining the battery).
I appreciate all the responses. Some of them are beyond my current will but I will keep them in mind for future use!
All Corvettes WERE tested right here in AZ at the Mesa proving grounds. You can still see the big circle on Google maps. They closed it down a few years ago and moved testing to MX.
10,000 Chevy Engineers can't be wrong! It's VERY HARD to do better than the OEM heavy duty cooling system.
Yes a BB fan will suck up up to 5 hp at max revs.
However Electric cooling fans are not FREE either.
I have seen more blown up alternators for that ONE REASON.
Alternators don't even really work at idle either...so you're sucking your battery dry at low revs.
To me, electric fans are the 'DEBIL'. lol So mis-understood!
I have 4 cars that have electric cooling fans as standard....they work terrifically...All have been designed that way from the beginning. All have PLENUMED fan shrouds. All have rubber ram-air flappers, All are two speeds. All cars have alternators designed for that load and thermostatic switches (2 spd). All have the fan shrouds covering the ENTIRE FACE of the radiator with gaskets!
All are watercooled VWS! (10,000 VW engineers can't be wrong EITHER.) Especially as VW's proving grounds were HERE as well!
Aftermarket fans= push the tin out the door with VERY LITTLE real world testing.
From: Arizona - If you don’t know CFI, STOP proliferating the myths around it...
Like mentioned...ditch that flex fan POS and move to either a stock GM fan assembly with shroud like designed OR install dual fans with a shroud. Either way should work. It always appears that Bubba has a much better way to do things than the engineers did.
Do I really need the engine mounted fan?
