I installed an electric fan and now it runs hotter!?!?

for what it's worth, this sounds like an airflow issue. i had a big block in my '51 chevy and i live in the desert. on the freeway i'd be fine, in stop and go traffic (mostly stop here), my temp. would climb to 230 and beyond. bad, very bad.
since the grill opening of a '51 chevy is small, not offering much airflow across the radiator, and modifying the grille/body was not an option i wanted, the next best thing was to make the cooling system bigger and get more air across it.

here's what i did, i made a copper plumbing pipe "circuit" that ran down underneath the passenger's side of the car and back up several times, a total of about 30 feet of pipe, increasing the cooling system by over another gallon and allowing the hot water to cool off more before entering the engine again. it was tucked up under so you didn't see it when standing near the car, but low enough to get air flow to it.

cheap, slightly time consuming, but WELL worth it in the end!

 

The only thing that was changed was the fan and shroud, so that has to be the main problem. He said it stays cooler at speed, so I doubt that air coming in around the radiator and inhibiting flow through it is the problem.

 

also, not to be a total asshat, but is the fan installed correctly?

it is possible to have a fan blow hot air the worng direction and heat things up a bit...

 

The shroud, and aggressive 7 blade fan from Speedway. That was a game changer....I wish I could fit a clutch but room doesn't allow.... I still am shocked at how much of a difference the shroud I made, and proper installation, made in my truck.....

A/C on, brass 2 core radiator, 85 degree day,,,, I am runnin 160 movin, and 170 in traffic..... I think I need to up my thermostat to a 180....

 

Like I said in my earlier post though, even a regular "nothing special" five blade flex fan created more air flow that the highest rated electric at the time. That was WITHOUT a shroud. That may have cahnged in the last 7 or 8 years or so, but I still would never go back to an electric fan, at least in my city's cooling situation. Nor would I ever install one on a customer car.

 

The radiator is a 4 core becool direct replacement for the Merc...and there's no shroud with this electric fan...it's just mounted directly in the middle of the radiator...the thermostat in the water pump is a 180 degree...

 

The water pump pulley is big...just like the crank pulley, so they're running 1 to 1...I drove it to work today...80 degrees outside...it was fine until I had to sit at stoplights...180 until then...at the first light it went to 200, back to 195 when I started moving, and then 205 at the second light...it went up to 210 when I was parallel parking it...

 

And I checked the iarflow on the front of the radiator before shutting it down...it'll pull in a piece of paper towel, but only from about 2 inches away...

 

Am I alone in wondering why you put on the electric set up after you got the mechanical on working right? Then my frustration is compounded by the fact that you won't just go back to the mechanical set up that you got working right in the first place...

 

I changed it because the shroud wasn't quite right for the radiator...lots of airgap and it was a real hokey 80's plastic truck shroud...

 

sounds like you still need to build a shroud for the electirc one.

Think what different from before when it cooled to now when it doesn't. Three Things :
1. how the fan is driven(electric)
2. the lack of a shroud
3. how the fan is activated (thermal clutch fan or electrical therm switch)


My money is on improper CFM of elec fan + no shroud. (with out being able to put my eyes on it.

-Levi

 

The location of the fan and the shroud is very important.

The blades shoud be almost touching the shrowd and the center of the blades (when looking down) should be at the end of the shrowd. (1/2 inside and 1/2 behind the shrowd)

 

Part of the problem is here, Change the WP pulley to a smaller one to spin it faster.

 

There is your problem..... Not enough air flow.... The radiator is plenty big.

I cant remember if your runnin the 4 blade, or the electric. But I think your runnin the electric..... And it aint enough...

Go to page 204 of Speedways catalog.... The fan that I am runnin is a
910-1575-17.... and I made a shroud.... There are many threads on here, regarding home made shrouds out of steel garbage cans that look great.

You simply aren't movin enough air....

When I put the fan on, it made a big difference with the A/C on up to 85 degrees, but when I made the shroud, I was standing at least a foot in front of the grill and it felt like a breeze.... At 1000 rpms, I can suck a shopping bag out of the air against the grill which is 18 inches in front of the fan

 

My friend's big block 65 El Camino ran hot. We went to an aluminum radiator, tried dual electric fans, Edelbrock high volume water pump, with no improvement. Put on a mechanical Flexlite plastic bladed fan and solved the problem.

 

Kid , check if your distributor vacuum advance is operating at idle speed and is it connected to correct port on carb. My 37 with Caddy mill always ran hot at idle and slow speed traffic , around 200- 215 degrees. with out a vacuum advance. Installed vacuum advance and it won't go over 180 in traffic now. It was running two electric fans behind rad. and one in frt. of it. now frt. fan not needed and back fans don't run as much as before.

 

And I guess these have been the first real hot days here in Texas, so it may have not been working properly with the mechanical fan either...I figured switching it over would be better, but maybe not...I haven't noticed a detonation problem anymore...it did it when I first moved here, and since then I've switched the points to a Pertronix unit...

 

If the shroud and fan don't work, then go to the pulleys..... Smaller on WP and Bigger on crank..... Overdrive pulleys.......

I am absolutely sure its your fan and a shroud... Those 2 will be the game changer...


PS a great universal shroud is on the 67 elcominos with the A/C option..... Its a great template for making one.....youll get the idea

 

Electric fans are for when you have no room for a mechanical fan, period. Then you deal with the shortcomings out of necessity.

Wait until your first one fails. Then your second. It doesn't even have to be the fan itself. I've had a lot of failures with those damn temp switches.

Put your time into properly setting up mechanical fan and BE DONE WITH IT.

 

one more thing that hasn't been mentioned is where on the radiator does the fan (either one) sit? if it is low on the radiator it will not cool as well as it would if it were higher.

 

Post 21 in this thread is great !

http://www.jalopyjournal.com/forum/showthread.php?t=733710&highlight=homemade+fan+shrouds&page=2

 

LISTEN TO THE DOCTOR!

Hope I got your attention...

#1 If you hooked up the distributor vacuum according to what Edelbrock told you in the instructions, it's WRONG!
You need MANIFOLD VACUUM to the distributor to run cool at idle and in traffic. It's the port on the driver's side. If you have your transmission vacuum modulator on there now just "T" them together. IF you have it on the passenger side port, moving it to the driver's side will probably cure your problem.
#2 That car had a rubber seal that kept hot air from going around in circles through the radiator. If it's not there now with the different radiator, invent one to seal the whole core support from the hot engine compartment

 

I'm looking at this issue not so much as a fan problem but an air flow or radiator issue. My position is to avoid electric fans as much as possible. A good mechanical fan, not one of those crap flex fans, is your best bet. Accompany this with a good fan shroud and position the fan close to the radiator to insure a good flow.

You didn't say how many tubes were designed in the radiator but many of the lesser priced aluminum radiators do not have enough cooling tubes so they have a tendency for the engine to run hotter than expected, you should have at least a 4 tube radiator core.

The next issue to address is air flow, you can have all the fans on in the world and you cannot cool down if you cannot get the air to flow thru the engine compartment. You say that the fan only draws from about 2" away so that is a sign that the air does not flow thru the radiator or flows thru and cannot escape the engine compartment. The inner wheel wells form a pretty closed compartment on this car plus the larges size engine blocks more area. I'd say some of your heating issue is due to the fact you can't exhaust the incoming air from the engine compartment and the air flow stalls out. With your engine running do you paper towel trick again inside the wheel wells and under the engine to determine if you are EXHAUSTING air from the engine compartment. If you have a low air flow or only air flow directed under the car, louvers placed in the inner fender panels will improve the air flow and help bring down the engine temp. Think of your engine compartment like a paper bag, if you fill it with air it gets harder to fill as the bag increases in size or more air is contained, poke a small hole in it and you can pump air thru it all day. Before you go purchase a bunch of parts try the air flow trick first.

 

re-install what works and doesn't fuk up your engine. keep the hood closed on cruise night

 

My 2 cents: If your still using the stock vertical flow radiator, they suck. Make sure the core is clean and flows properly. (radiator shop can test) Everything else will have to be right on in order to survive. Max anti-freeze mix 50-50, too much anti-freeze will raise the temp. The engine sounds like it's lean, a definate heat adder for sure. Go with a 160 stat and a lower temp switch, also 160. I would use a 16" spal puller fan, 2-14" ones are better. Check the timing as mentioned but don't retard any more than you have to or that will add heat too. Good luck!

 

Did ANY of you read the question I asked, and the answer he gave about sealing to the radiator with the fan? Whats happenning is the air is being pulled around the electric fan sides and not through the fins. Makes a HUGE difference. Air will flow the path of the least resistance.

Take everything else off the table for now. Yes, timing and fuel can cause it. Yes, a mechanical fan can cool better than electric, not always. Yes, electric are not traditional. Yes, he shouldnt smoke.

But, until he cures that sealing problems, you will be throwing out ideas what it COULD be till the cows come home.

 

OK, not directly related BUT: when I drive up to the stop lights or any situation where I know I'm going to be stopped for a bit I put the shifter into neutral.

That way the motor can rev a little faster (if you're running a mechanical fan it can be handy) and there's no load on the motor, it's not 'fighting' the torque convertor.

And I only have one large electric fan that operates from a switch on the dash via a relay, never had it overheat - but then a '55 F100 radiator is BIG!.

 

Some interesting stuff being posted here.

If electric fans are so terrible, the OEMs must be just about penniless by now. This is because just about every cooling fan for the past 15 years has been electric. Replacing 2 electric fans a year on each car sold must really add up for those OEMs, huh?

Thermostats ... 160 degrees? For what purpose? So your temperatures don't climb too far when stopped? They shouldn't climb much at all when stopped. If they do, the system isn't working properly. A lower temperature thermostat is a band-aid.

 

Its pretty clear.... He has an air flow issue..... No biggy.....

 

Normally, an engine will run approximately 10 degrees higher than the thermostat rating if the system is operating normally. Since he is not concerned with reburning engine fumes and blowby for pollution control, why start with a 190 stat when it will never run below that temp unless it's warming up? That's the purpose.