Hello all. I’m having over heating issues while standing still. Have any of you installed an aftermarket electric fan? I bought one, but the under side of the hood hits it before it gets to the lock out position. Anyone know of a super thin fan with at least 3000 cfm? Thanks all.

 

2200 cfm low-profile E-fan will do the job unless you are set to buy a thick 3000 cfm
E-fan.....and make sure all the weatherstrip is inplace....
I could not get proper cooling in traffic until I installed new weatherstrip around and across the top of the radiator

 

most of us run twin electric fans. look at Summit for fans that fit corvette or just about any Corvette supplier. Some guys run a ford fan,a DIY kinda thing if your on a budget. I'm sure someone will chime in with which ford fan that is.

 

Thanks fellas. I’ll check out the 2200 cfm e-fans and seal up the radiator. I also have an old radiator. Would you guys suggest buying an new more efficient one?

 

Travis, we know nothing about your car. However keeping engine heat down on C3 Corvettes is a common problem. over the years there must be a hundred threads on the topic. I would suggest you do a google search or two on C3 Corvette overheating. most things google will pull up will lead you back to this forum. Also at the top of this main page is a sticky called Aluminium radiator's and related topics, please read it. TONS of information in it. Cheers.

 

Are you trying to add a pusher fan to the outside (front) of the radiator?

Like many, I added a dual-Spal fan as a Puller fan to the inside (back) of the radiator. The one I bought has it's own shroud, so I removed the stock shroud and clutch fan setup.

But please post photos, and search the forum! There are lots of ways to do this, and you may find that a radiator is easier for you, and lets your stock clutch fan work just fine.

 

What engine do you have?
If your timing is off, clogged fins hindering airflow, corrosion on the inside those can all contribute.
Most alum radiators these days make a very noticeable difference. I was surprised going from a 4 row to a nice 2 row alum piece how much quicker it cooled down.

Unless you have something fairly radical a 16 in spal should take care of most issues.
I like the idea of a new OEM fan. Any truck, luxury car...heck even a 6 cyl car I bet are better than most aftermarkets plus the longevity issue.

 

Yes.... you should flush your radiator or look at getting a newer aluminum radiator. Look at a puller fan not a pusher and get rid of the stock fan all together. You will need to up grade your alternator to 100 amps if yours isnt near that. Then you ill need to add a new charging wire from the alternator to the main starter lug.

 

the fan normally goes in the side of the radiator closest to the engine not the front of the rad.. thats the only way it would hit the underside of the hood when you open it.

I put these on my car to replace my stock clutch fan and shroud which I tried getting to work better first with a new clutch and foam noodles to seal up any gaps.... Temps used to creep up over 190 just sitting for 10-15 minutes in traffic. Now they havent gone over 174. even when I left it running in my driveway for 20 minutes yesterday when I got home as a test. I went with dual fans for the added safety of having one if the other fails to prevent catastrophic overheating https://www.ebay.com/itm/271870684127?hash=item3f4cc16bdf:g:fy8AA MXQ~6VQ7kxV

I did upgrade my alternator to a 105amp version and added a second heavier wire from the alt to starter..

 

There's your problem. Put in an aluminium rad. Electric fan set ups are expensive and you don't need it. Replace the clutch on your mechanical fan if that's wore out but replace the rad first and see how that works out.

 

Depending on the faulty condition of your radiator, you might be able to clean all the old gunk and deposits out of your present radiator with radiator CLEANER (not radiator flush). Or you might just 'bite the bullet' and replace your 40 year-old radiator with a new aluminum unit. There are several good quality aluminum radiators available for very reasonable $$$ (around $200). As mentioned, your thermal clutch type fan is just fine...as long as the thermal unit is working OK. There is no benefit to installing electric fans, as BOTH types use the same amount of power to get the same job done. One uses mechanical power (thermal fan) and one uses electrical power produced by a harder working alternator. Why spend $$$ on electric fans and upgraded alternator and wiring if you don't NEED to???

You might also consider replacing your thermostat with a new 180*F unit. If the thermostat is defective, cooling system can overheat, as well.

 

I guess it depends. I paid more for the champion radiator than I did for my fans..but with the accessories needed it was a wash and I had already upgraded my alternator when mine died years earlier... In my case not only did I buy a new 3 core aluminum rad, I did waste money on a new clutch and multiple thermostats and even lower rad hoses only to find out it wasnt the reason for my higher temps so YMMV..

And I guess we will just beat a dead horse here but unlike some of the people posting above I actually HAVE the additional experience of having both the stock cooling system and an all new stock cooling system as well as that same cooling system with different hoses and electric fans on the same car which I am using for the basis of my comments...

Electric fans cool more effectively at full rpm while sitting at idle... clutch fans are limited to the rpm of the engine (when you actually need them the most they are literally being powered by the lowest rpm the engine sees)... Clutch fans always run to some extent putting parasitic drag on the engine.. Electric fans do not they only draw power when they are needed period, thats a huge difference in itself. have you ever seen your mechanical fan turn off while the engine is running regardless of temp? No the clutch still provides resistance and drag and theres a decent time delay before the clutch both comes up to and down in temp.
Electric fans draw an estimated 1-3 HP when they are on and the alternator is charging the battery they are running off... Multiple tests done by multiple people have shown mechanical fans draw as much as 10 times that HP from the engine depending on rpm but the more rpm your engine is turning the more power is lost. Dont just take my word for it or the folks on this forum though... Do your own research... Heres one such thread elsewhere on it recently shared in another thread here. https://www.speed-talk.com/forum/vie...hp?f=1&t=63452 The general concensus opinion on the actual performance /hot rod oriented forums are a shifted bit differently than just the classic car enthusiast forums and this is likely for a reason.

 

A good one should...so many out there that are lackluster. not impressed with the 2200 spal I guess its borderline for my app anyways but compared to any mech/flex fan the electric doesnt move much air. Time to upgrade
Ideally a mech with an electric as a secondary is ideal . Believe in bulletproofing systems.

Running in a driveway vs in traffic or driving with a load are two totally different things.

 

Mostly anecdotal comments...very little data in those "observations". The thermo fans do not draw much air at idle IF THEY ARE NOT ENGAGED (not hot enough to call for them). When engaged, they do draw significant amount of air at idle, as evidenced by the much louder fan doing its work. Obviously, the mechanical fan at idle does not have the same flow capacity as electrics; but at idle, they shouldn't be needed at all.

The whole purpose of the thermo fan concept is to keep the engine noise as limited as possible, but still have the capability of enhancing cooling, when needed (and not using any more mechanical energy--and fuel--than needed), Unless a vehicle with a thermo fan is moving very slowly on a hot day (and maybe with A/C running), the fan is not likely to engage at all. Certainly when at speed, there is no need for it. If electric fans were to operate similarly, they would not only "run", but would regulate their speed based on coolant temperature....max fan speed when approaching upper 'comfort' limit of coolant temps.

 

Way to go captain obvious. But your statement that hey are not needed at idle is incorrect


I too wwent through multiple set ups and have to agree that the stock set up isnt up to par at all. Yes there is a difference at idle and at full load on the highway, THe electric fan with a PWM contoller wwill keep the car cool by contolling the fan speed from low speed to full bore, the stock fan wont do that. At full load on the highway neither fan is doing jack, its just forced air through the radiator

I had a small block dewitts radiator and the full stock fan and shroud with all new seals....at the beach it wasnt cutting it putting along the hot asphalt at rolling speeds.... More than once it barely got me out of there before it overheated. Same thing happened in construction traffic on a hot summer night. Once the traffic got moving I was fine....because the fan was out of the equation. I ditched the stock fan and shroud for a full plastic shroud and asingle big *** spal fan..Its obscenely loud but kept the 350 hp motor cool. Once i started upgrading the 327 internally, THe small block radiator wwas lacking. II added a bigger air dam and it kept the temps cool on the highway but the hot slow beach traffic again got to be an issue. SO I went to a big block radiator with no other changes and the temps came back down to about 180*.

Now I have a big block with 10.5:1 and .540 lift. THe same system keeps it about 175* at idle and on a cool day on the highway. Its about 195* on a 90 degree day at 80 mph. Still very good

 

The speed-talk thread, https://www.speed-talk.com/forum/vie...hp?f=1&t=63452 , was very a interesting 6 page read. At least one well known member, tuner, called out EM's 30 hp loss at 6000 rpm with a clutch fan. He wasn't the only one who questioned that amount of hp loss although most over there agreed there is a loss but nowhere near 30 hp.

Anyway, I still use the clutch fan with a hd aluminium rad and it cools effectively just like electric fans, I guess. Not sure what is meant by effectively by other members definition but mine is that it keeps the car at its normal operating temperature at idle up to highway speeds. Gauge doesn't move very much at all. Very happy with the clutch fan.

 

Engine masters covered all the fans a year or so ago...the forum already had this conversation. THey found they lost 20hp with a clutch fan. THe non clutch flex fan also lost quite a bit of HP.. They also did a water pump and alternator test as well

 

You won't ever hear me argue against installing a high-CFM puller-style electric fan. But if the OP ever does return, here's my simple list of things to do, roughly in order from easiest to hardest. It is very likely that the OP can solve his problem long before getting to the end of the list. Note that this is a general list, and not specific to the OP's problem at idle/stopped.

• Post some photos of your car!
• Use an infrared thermometer to check your upper radiator hose while running, and see what temps you are actually getting to.
• Check for leaks
• Check your belts, hoses, and (when cool and safe too do so) make sure your radiator is topped off
• Feel that the lower radiator hose spring (internal) is intact
• Check that the seals around the radiator are intact
• Check that the chin spoiler is fitted (not sure about 68s)
• Make sure the clutch fan is working properly, and you have a proper fan (not a flex-fan)
• Check your heater core for leaks
• Have your rad cap tested
• Check your timing. Something as simple has having the vacuum advance on ported vacuum can cause extra heating at idle
• Flush your coolant, refill with 50% deionized water, 50% ethylene glycol concentrate (green stuff, unless you have aluminum heads). Pull the plugs in your block, and flush the engine.
• Replace the thermostat with a 180 degree high-flow unit (Milodon makes them, for example). Drill a small hole (3/32") in it so there is always a small amount of flow, and air doesn't get trapped when filling. A good time to do this is when flushing the coolant.
• Upgrade your radiator to aluminum.
• FINALLY, correctly install an electric, high-cfm, single or dual, Puller fan, correctly*, and remove the clutch fan.

*I leave the electric fan for last because it requires significant alterations to the electrical system, including a high-output aternator, fuses, relays, and charge circuit wiring changes. Done correctly and hired out, parts and labor should cost two to three times what a new radiator would cost.

 

I've never seen an electric fan that moves anywhere near the air an engine driven fan can move, so when it comes to cooling you will not beat the engine driven fan. The electric fan is a good compromise to HP vs cooling. Even at idle the OEM fan will move more air when fully engaged then the electric fan.

The best electric fan on the market is the Mark VIII fan when it comes to moving air, airflow vs amps vs voltage, Mark VIII is on top with around 30 amps draw.

flush your radiator, check condition of the interior of the radiator it may need cleaning, make sure the core support seals and all there and still in place, verify the fan clutch is working as intended.

Neal

 

I have the dual 11" spal "clone" sold on ebay .. I decided to do more testing on it today. One of the 2 fans is almost enough to maintain temps at idle after a long drive but the second fan is needed to kick on and off after idling in the driveway for a while and the engine reaches about 182 degrees. Once the second fan kicks on the temp drops back to 174 or so pretty quickly and it kicks off for a while but the temps did creep back up requiring it to kick back on a short while later. Oddly enough while putzing around town the temp never goes over 174. I also added a large auxilary trans cooler in front of the main fan (fan that kicks on first at lower temp).