Electric cooling fan temperature

[AFD 792]

What on/off temperature are you setting your electric radiator fans at? I'm currently running with the fast ez2 efi system that's controls duel fans, I've tried 180*-205*. My issue is that the car will run in the garage for as long as you want, fans turn on and off keeping around 195*. Driving seems fine until you hit a continuous speed and the temperatures will continue to rise to the 230* plus range and doesn't seem to be able to cool down idling. If you turn it off and let the fans run for 10 minutes it will drop back to 200*. I've read that electric fans can actually block air flow at certain speeds. Car starts and runs great for the first 20-30 minutes. Specs are 600hp with the efi controlling everything, timing and a/f are good, Griffin 2 row radiator with spal fans rated to cool 800hp. Any advice is appreciated

[WHITE AND RED 69]

At speed the fans shouldn't be needed in most cases. The airflow should be enough to cool it down so it sounds like the coolant isn't staying in the radiator long enough to cool down or not enough air flow. Or there is air in the system. What water pump and thermostat are you running? Are the fans pusher or pullers? Do you have a spring in the lower radiator hose to keep it from collapsing?

I have mine set up to come on at 190 and turn off at 175.

[AFD 792]

White and Red
-I've tried the high flow and standard water pump. It's a Eddie Motorsports serpentine system that is counterclockwise rotation at the water pump, but haven't seen any issues. No difference
-160* and 180* thermostat with a bypass hole drilled in it. Did try a coolant restrictor with 5/8 hole. Can see a nice flow. No difference
-2 puller fans just under 1000 cfm each with a shroud and extra air flow holes in it.  There's not much room between the fan and pulleys
-The lower hose does have a spring in it.
Seems like I need to get the fans to turn off at a certain speed.
Talked to a "tech" at Fast, zero help.

[igozumn]

I put a dual electric Ford Contour fan on my aluminum radiator, after putting the Fitech on.  One of the reasons, well, benefits really, with the Fitech, was the dual fan control on my particular unit.  It cooled fine around town, sitting in traffic.  But seemed to run warmer out on the highway, or at least start to creep up a degree or two, another degree or two and so on.  3.91 gears and N50-15, the engine wasn't running redline at speed, so, shouldn't have been an issue.  Aluminum water pump housing, Milodon pump (if I recall), when I converted to the Fitech.  Like mentioned above, most if not all cars on the road should cool properly on the highway without a fan, in theory.  Coming home from a car show, I decided to experiment.  I turned off the fans in the Fitech controller on the highway and watched the temps climb.  Turned them on and watched them come down.  Did it again to double check.  Went so far as to pull the electric fan unit out, and swiss cheese the shroud to try and let more air flow through at highway speed.  Didn't really help. 

 Was about to experiment with the old, OLD deep pitch flex fan I had taken off and had since '89, or a stock 7 blade original fan and clutch, when I put a 5 speed in with the .64 overdrive fifth.  I'm now turning 2100-ish at 70-ish.  No more heating issue for now.  

I know that the old carb I had was running super rich.  And that the new Fitech has leaned it way back to what should be normal, if not slightly leaner maybe.  Obviously it's running hotter than it was before, but better of course.  It's running hot enough, I can feel the heat in the interior, which was never an issue.  It's running hot enough with the stock exhaust manifolds, it melted the plastic bearing retainer at the end of the steering column.  

I will also say, my stock temp gauge had not been accurate.  So, until I put the Fitech in, I didn't have any real grasp of the actual operating temps.  Had a couple people recently say, maybe I should go in and adjust the target AFR, to combat the heat issue a little.  Maybe.  We'll see.  

[WHITE AND RED 69]

If all the normal culprits are not the issue then time to move on to the rest. What is the timing set at?

Any photos of the fan setup?

[AFD 792]

Timing is set at 16 and 34 total. A/F ratio 14 cruise and 12.5 WOT. Plugs look good. Coolant temp appears to drop about 20* from top to bottom, but has a wide range depending on where you shoot the temp gun.  I'll work on getting pictures this weekend.
Does anyone use a coolant restrictor in the bottom of the radiator?
What should a minimum cfm be?

[forphorty]

If I understand correctly, you are spinning the water pump backwards? Can't imagine that working well.

[darbgnik]

I think I have my electric fans coming on at 185 and the second at 195, maybe. Don't have an issue with a 3 speed auto and 3.55 gears.

That being said, electric fans will never flow as much air as a mechanical fan with good shroud. So in that aspect they are not an upgrade per se.

[flyinlow]

I have always used fan controls that sense the temperature of the radiator not the engine water jacket. They come on around 160* keeping  the coolant in the radiator return below the 180* that the thermostat regulates at.

I have EFI and thought about moving one fan control to the ECU so the fans would  be staged ,but have not done it yet.