Has anyone successfully replaced the viscous fan with an electric one?
If so, any caveats, and what size, brand, and from what other vehicles
would work in a W124?

During track use at Willow Springs, the viscous fan at lock-up seems to be drawing 10-15HP.

TIA,
:-) neil
1988 360TE AMG

I don't have the actual article anymore, but HotRod magazine did a comparo on how much horsepower was "gained" simply by turning off and/or disconnecting electrical components during drag racing. Theory was that excess electrical draw caused the alternator to engage at an earlier stage, therefore causing loss of horsepower.

Whether an electrical fan is more draining than a viscous fan would have to be tested. A more extreme application would be a second battery to power the fan directly as I would estimate the weight of an extra battery would be less a drain on horsepower vs. the other methods of cooling.

Just my $0.02 worth of speculation.

__________________
krahe :~)
85 300E euro-spec., twin-turbo AMG aero kit
89 300CE AMG aero kit

Ke6dcj,

Don Swinford changed his engine fan to an electric, and so far I believe he has been pleased witht he results and all.

You should get in touch with him to find out whta he used.

Alon

__________________
'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon

Brothers of The Benz, Neil and Hi Alon you rascal you!
I have a electric fan on my 1987 300E and it does quite well.
It is electronic thermostatically controlled using a 35amp mini-relay fused at 25 amps. The thermostat thermocouple is at the rear of the radiator held tight against same.
My first fan was a 16 inch straight blade without the fan schrod.
It would not maintain 90 C when stopped with the A/C on. The cooling system would go to 100 C but that isn't too bad(212F).
I replaced it with a 16 inch "S" blade higher cfm using the OEM schrod and now the radiator temp is constant at 85-90 C.
There is still a problem with battery capacity. With both fans on, the OEM and the new one, the current draw is more than the alternator output has at idle speed.
When stopped in Neutral and A/C on, I increase the engine speed to 1000-1500rpm and I have no problem.
As for the increase in performance, maybe 10% in fuel economy and a much smoother and quiter engine with an improvement in throttle response.
Good luck.
Happy Trails Beep Beep from The Spiderman in Houston!!!

I am going to replace engine driven fan with electric on my 126. The viscous clutch went out and I feel now is the perfect opportunity to test the electric fan theory. I plan to put dual 14 inch fans on that are thermostatically controlled. should save on fuel as well as a slight increase in horsepower. I gets pretty hot in Georgia in the summer so I hope the fans are up to the challenge!! If anyone has tried this, I would appreciate any feedback, otherwise, I will let you all know how they work.

Regards,

Matt

I'd check out the flexi-a-fan brand of electric fans, specifically the "Black Magic" series.

Supposedly pulls over 2500CFM.

Let's us know what happens.

:-) neil

I have gotten the fan installation completed. Installed 2 14" electric fans in place of original fans. They are controlled by a single thermostat which I wired to individual relays to handle the power consumption of the fans. I did not get the good brand fans because this was kind of an experiment, and I didn't want to throw away alot of money if it didn't work. Just went down to the local auto parts store and bought 2 cheap ones and 1 thermostat. Then went to the electronic store and picked up 2 12v 30A relays. Went home and dug in. About 2 hours later I was done. Now for the test... after adjusting the thermostat to proper range I turned the air conditioning on max and let the car idle while I watched and waited.. SUCCESS!!!
After 45 minutes of idling with the A/C on the temp was perfect!!! However I did save the original fan, fan shroud and hardware for potential resale in the future.
So anyway, there you have it... electric fans will work, and work well

How loud are the electric fans? I too am thinking about replacing my viscous clutch-driven fan with electric units.

Thanks,

Satish

The fans I bought are not loud at all, you cannot hear them from inside the car at all. If you are outside the car and the engine is idling and the fans are on, you can hear a slight humming. Inside the car... the only way you can tell they are on is by watching the temp gage. Fans that I purchased are made by Hayden and I have 2 14 inch fans that come on at the same time. You might be able to get away with 1 16 inch fan but remember the idea is to cover 70% of the radiator at least.

Any idea as to what brand and model number of fan? Also, do you the CFM it can pull?

Thanks,

:-) neil