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Cooling issues electric fan and aluminum radiator upgrade
So I decided to upgrade
I have a 400sbc with vortec heads and stock bottom end
i have a 2 core 1” tube aluminum radiator brand new
i installed 16” 3000cfm (supposedly) electric fan
toggled between 180 and 190 thermostat, the one for the fan switch is a 200 on and 180 off switch mounted in the port next to the thermostat on intake manifold.
regardless of the set-up while at idle the temperature increases past 220 at which point I shut off because it’s still climbing it takes a solid 10 min to get there but while driving around st a stop light it goes faster
while I am driving down the road the temp is perfect to what the water pump thermostat is
COOLS PERFECT WHILE DRIVING
so... I installed a 110A alternator thinking the fan was not getting enough amps at idle.... to no success
i am NOT running a shoud is this my issue?
what do you all think I am doing wrong?
edit: it is overheating WHILE fan is running at idle
edit: it did not do this before with brass/clutch fan set up same timing etc. it would
climb at idle but stop at 210 now it goes beyond
Last edited by Averystingray75; 12-29-2018 at 10:47 AM.
Since it is cooling well while driving, the missing foam seals around the radiator and support are not an issue. It seems like you have an air flow issue while stopped, that would be the fan. Are you sure it is installed correctly, as in correct rotation and using a puller fan, not a pusher on the wrong side of the radiator? Another issue is timing, going through the tune and getting the timing right with the vacuum advance hooked to manifold vacuum will help it run and idle cooler. If you want to optimize the tune and timing, email Lars at v8fastcars@msn.com .
Another issue is timing, going through the tune and getting the timing right with the vacuum advance hooked to manifold vacuum will help it run and idle cooler. If you want to optimize the tune and timing, email Lars at v8fastcars@msn.com .
Same fan, switch same thing. Its going to heat up at low speed/idle til you start moving or the fan comes on. If you use the 185 on switch it will run constantly.
They make adjustable controllers but have yet to see a reliable one. I have a shroud on mine...cools down a little quicker when stopped thats it
Unless your timing is way off its doing what its supposed to.
I work on the 1984 to newer Corvettes that no longer have a water pump driven fan on the water pump and they only have electric fans.
Knowing you have an electric fan....somewhat like what GM used on the Tuned Port engine cars. BUT GM does have a nice shroud assembly for the fan so it can pull air through the entire surface of the radiator core and NOT just one area. The engine can sit idling and get all the way UP TO 226 degrees Fahrenheit and THEN the cooling fans would come on and cool it down to about 201+ degrees or so. This is NORMAL.
So...knowing you cooling temps are fine when driving it....just like the 1984+ year models...Because a 1987 sitting in a bank drive thru idling for while will do just like what you car is doing. I feel you do not have an issue IF...and I repeat IF the fan when idling will pull the coolant temps DOWN when the fan is on when idling.
Now this fan is not going to pull it down to like 150 degrees...just down to the point where whatever type of thermostat you have it is bringing it down to that temp value some what. And knowing IF your coolant temp gets pulled down to like 190 or so..I would not worry.
Because when I am testing a cooling fan circuit function on a 1986+_year model Corvette I let it get hot enough to turn the fan on ...then when it cools down and the fan shuts off ...is sit there and watch the temperature begin to climb again and wait for the fan to come back on an cycle a few times so I know it is working.
I seriously doubt you have any timing issues....from what you wrote.
NOW.....if you car is an A/C car.....this electric cooling fan can possibly not be good enough due to tit may not pull enough air across your condenser when idling and your high side pressure can skyrocket and get dangerously high.
The fan running will not cool the engine alone I must drive it to cool it if it is sitting and st
idel and fan is running the temp
will continue to climb until I shut the engine off, or drive until adequate airflow cools it
The car has NO AC only an external a/t transmission cooler
other questions my timing is set very high (30 degrees total with vacuum) vacuum and everything hooked up properly
set up worked before with clutch fan and brass radiator it would climb at idle but not this fast and bad
Not to mention I want this fan set up to cool anythinfadvanced timing etc
A far more advanced engine will go into the future and I need this cooling set up to work I want it too cool at idle in a desert regardless
of the engine
I have a similar setup on mine, and have no issues what so ever. The aluminum radiator has 1 1/4 inch tubes, but other than that the same setup. My fan is a Spal 16 inch 3000 cfm fan driven by a PWM controller. It will spin up the fan slowly as temps rise at idle, and be full on at 190 degrees. When the temps drop it will slow back down, or even stop running when not needed.
FWIW my 406 runs 36 degrees timing locked out. Cam is huge, pushing about 540 horsepower for now....
I think you may want to check the coolant level. These cars with the radiator tilted back and lower than the T stat are all but impossible to completely fill. I jack mine up in the front as high as I can on the passenger side, fill the radiator with the engine hot and running till it spills out, and then cap it. Be sure the reservoir is full. When it cools down you'd be surprised how much the reservoir goes down. Usually takes a few cycles to get all the air out of the system.
Last edited by The Money Pit; 12-29-2018 at 10:56 AM.
You'll need a shroud on that fan for when you're stopped or running at low speeds. The issue you might have is that you may need "flaps" in the shroud to allow air flow at highway speeds, and most of the "flaps" you can get are designed for a vertical installation. With a tilted radiator, they don't work the way they need to.
Honestly, I avoid aftermarket/"performance" electric fans as much as possible. If I must use an electric fan, I find a used OE setup that fits the radiator. Common potential donors are Ford Taurus/Mercury Sable, Chevy Impala, Dodge Caravan, 4th gen F Bodies, C4 or C5 Corvettes, Dodge Intrepid. You need to measure your radiator, and take your tape measure to the parts yard and see what comes closest.
3000 CFM is a little marginal, too. In the aftermarket, that's a "high flow" fan, but it's really not all that great. Most of the OE fans I've mentioned actually exceed that by a good bit (most of the ones I mentioned are between 4000 and 6000 cfm for the fan or set on the cars mentioned). OE fans have to protect the engine for the entire warranty period. No aftermarket fan manufacturer will wafranty anything more than the fan itself. Partly, that's because they can't stand behind the "engineering" of the installer, but it also tells you something of the quality of the parts you're getting.
I’ve run a lot of cycles and topped off coolant
I removed and replaced the old brass radiator and never had problems
I’m confident it’s as full of coolant as possible.
so the setup with spark fan howmis it mounted to the radiator? Is it right? I have a small gap on mine wondering if that’s the problem? Mine are not a name brand fan it’s generic.
Without a shroud, you have air flow only directly in front of the electric fan. The rest of the radiator has no airflow if the vehicle is stopped, and does little cooling. That's your biggest issue with it idling at a stop. Nothing but a good shroud system will fix that.
As I said, the best approach is to get a "stock" electric fan setup from a similar weight vehicle.
It's really tough to beat the factory mechanical fan and clutch (with the factory shrouding) for cooling. That factory fan moves a lot of air, even at idle as long as the clutch is well maintained (replaced regularly, and always as a unit replacement when water pump is replaced). The "horsepower losses" are minimal if the clutch is working. The fan freewheels when you're at highway speeds. You might loose just a little bit off the line starting in hot weather, but once the air is moving and cool enough, the fan clutch disengages.
Fan shroud.....i did same thing with similar symptoms. I ended up following some on here and used ford focus fans. Worked well for the higher compression 383 sbc and cools my ls3 still at idle.
I saw a lot of people running shroudless so I figured I’d give it a try
concerned it would cause restrictions while driving and rendering me dependent on the fan instead I wanted it only to run while at idle and turn off while driving.
so I was thinking Maybe getting second elec. fan for more surface area or should I really just get a shroud?
You've got to have a shroud. Period. I've got a 3300 cfm , This one...https://www.summitracing.com/parts/flx-180 , It has an integral shroud, and keeps my 440 sb cool in the heat of summer, 170°-190° at all times. It would not function well without the shroud.
I saw a lot of people running shroudless so I figured I’d give it a try
concerned it would cause restrictions while driving and rendering me dependent on the fan instead I wanted it only to run while at idle and turn off while driving.
so I was thinking Maybe getting second elec. fan for more surface area or should I really just get a shroud?
Go to the junkyard and get an electric fan and shroud from something there. If you're concerned about the state of the bearings and electrics, go to the $tealership and get a new motor for that fan. It will be way, way higher quality than any Chineseum fan from eBay, and higher performance than anything sold by any online "speed shop."
Get one that the shroud is about right for your radiator.
And I'm having brain farts here. Does the top of the C3 radiator lean forward? Or backward? If it leans forward slightly, then most conventional "flaps" in factory fan shrouds will still open, but might take higher speeds to fully open. If it leans backward at the top, you might have to put some foam and/or plastic to frame the partially open flaps, to close them off when you stop and prevent the fan from sucking air in through the flaps instead of through the radiator.
Last edited by C6_Racer_X; 12-29-2018 at 01:22 PM.
I have a similar setup on mine, and have no issues what so ever. The aluminum radiator has 1 1/4 inch tubes, but other than that the same setup. My fan is a Spal 16 inch 3000 cfm fan driven by a PWM controller. It will spin up the fan slowly as temps rise at idle, and be full on at 190 degrees. When the temps drop it will slow back down, or even stop running when not needed.
FWIW my 406 runs 36 degrees timing locked out. Cam is huge, pushing about 540 horsepower for now....
I think you may want to check the coolant level. These cars with the radiator tilted back and lower than the T stat are all but impossible to completely fill. I jack mine up in the front as high as I can on the passenger side, fill the radiator with the engine hot and running till it spills out, and then cap it. Be sure the reservoir is full. When it cools down you'd be surprised how much the reservoir goes down. Usually takes a few cycles to get all the air out of the system.
How does your car behave with ignition locked out vs using a curve?
Im on the verge of needing to do it. Car runs great but could use a little more initial. Manual trans if it helps and never lug it
The shroud will help draw air across the whole radiator instead of the fan diameter area. It is possible the fan doesn't have enough cfm too. Just let the fan tstat/controller setup control on/off of the fan(s). The focus fans arent a perfect fit but is close and still barely fits between the a arms.
My cam is 254 degrees at .050 and with a LC of 108. Idle vacuum bounces between 6 and 8 inches at 1100 rpm idle in gear. Drove me nuts for a year trying all sorts of vacuum cans, distributer recurve kits, and carb tweaking. Finally locked it out and low and behold....it'll idle all day in gear. (Mines auto with 3000 stall) A manual would not have been a problem at all.
There is no hard start, no hesitation, surging, pinging, or any issues other than a slight loss of mpg,....but who cares. I have a Quick Fuel 750 with annular boosters, billet metering blocks and throttle body, with no choke tower. A few weeks ago I fired it up after sitting for months,....in 28 degree weather,...still had snow in my driveway, and took it around the block with open headers.
12-29-2018, 09:15 AM
Cooling issues electric fan and aluminum radiator upgrade
