Mechanical cooling fan vs electric

[Dino01]

Interesting vid. The Tundra in my sig is pure mechanical, the RX and Honda are all electric, but the Mercedes has both mechanical and a couple electrics on the front of the engine; and when comparing engine temps in extreme conditions (never scanned the RX) with my SGII, I've found the Mercedes to easily be the most effective. Of course the others are just fine, but the MB seems to be the most "stable."

I've never seen the Benz exceed 100*C even in the most extreme conditions, think 120*f out in the desert with the A/C blasting and climbing up a mountain pass at somewhat slower speeds. It has a "real" temperature gauge that is always reflecting what's going on in the engine, rather than a dummy gauge, and you can enter diagnostic mode with climate control unit to get an accurate temperature readout digitally accurate to 1*c apparently. In any case, in the same conditions I've seen the Tundra and Honda both exceed 110*c, still not too alarming given the conditions, but the big Benz V8 seems to top out around 100*c and not go any higher. Of course when you pop the hood on a hot summer day all have a lot of air moving, but the Mercedes has A LOT more air moving around the engine bay than anything else I own, perhaps they are onto something.

 

[SHOZ]

A bigger radiator will go a long way for cooling. I put in a double thick one on my Gen Coupe 2L turbo and it can idle for 10 minutes in the hot summer before the fan comes on at 200f.

 

[brave sir robin]

I thought about switching over to electric fans in the Electra but decided on a proper thermal clutch set up. All I know is that whenever I go to car shows there are always people complaining about overheating yet I can sit there all day long with the ac running and have idle temps never go over 200*. At engine speeds above idle the temps drop to closer to 180* with ambient 100*

The secret is properly engineered designs whether they are electric or mechanical.

 

[SteveSRT8]

Originally Posted By: OVERKILL
Originally Posted By: funflyer
Originally Posted By: Olas
I wonder why mechanical fans are still in use with the availability and benefits of electric fans.
Good video though, illustrates how much difference can be made by something you wouldn't normally give a lot of thought to.


Extreme cooling requires extreme CFM, something that no electric fan can do compared to a proper mechanical, engine driven fan.


A Mark VIII can move upwards of 5,000CFM. There are VERY few applications that it cannot keep cool.


Seems my old 05 Silverado had 2 big electrics on it, sounded like a hovercraft from outside, never ever got hot at all, sat right on the thermostat.

My wife has done reports in the SRT, sat in 107 degree heat for an hour and a half, never got hot. Fans on that car rarely go on high speed except for a 30 second burst. Must be adequate airflow as AC is amazingly effective.

All our service vans are mechanical only, the RAM has a tiny electric up front which seems dedicated to AC function. Big mechanical fan also.

I have used that Ford fan on projects before, it is a small hurricane with commensurately large current draw...

 

[OVERKILL]

Originally Posted By: SteveSRT8

I have used that Ford fan on projects before, it is a small hurricane with commensurately large current draw...


Yes, it is pretty much the "go to" for any build that somebody needs to keep cool that is going to make a ton of heat. But as you noted, it draws a ton of current to get moving. When I've used one, I opt for an RV relay, which is essentially a solenoid rated for constant duty and looks just like an old Ford starter solenoid. I've never had one fail, whilst that puppy will melt your common fan relay setups in no time flat.

 

[SteveSRT8]

Originally Posted By: OVERKILL
Originally Posted By: SteveSRT8

I have used that Ford fan on projects before, it is a small hurricane with commensurately large current draw...


Yes, it is pretty much the "go to" for any build that somebody needs to keep cool that is going to make a ton of heat. But as you noted, it draws a ton of current to get moving. When I've used one, I opt for an RV relay, which is essentially a solenoid rated for constant duty and looks just like an old Ford starter solenoid. I've never had one fail, whilst that puppy will melt your common fan relay setups in no time flat.


Yepper, I ran one on a project truck we built here. It drew something like 50 amps IIRC! Had to get a bigger alternator and upgrade the wiring!

 

[Ducked]

Originally Posted By: Shannow
In he '1990s I was muckeing around with Cooling Systems (sent some stuff over to Gary Allan).



......and took the seal strip off the rear of the bonnet, .....


Mine came off. Been wondering if I should bother to stick it back on....

Apparently not.

 

[Falcon_LS]

After watching that and now that I think of it, I like the PCM controlled Electro-Viscous (EV) cooling fan used in GM's GMT360 platform for a number of reasons; better efficiency in stop and go traffic, improved fuel economy, reduced fan noise and it ensures the AC compressor operates at a lower head pressure. The fan uses an electronic solenoid, using a PWM signal from the PCM, and will automatically be commanded to 100% if coolant temperature hits 264 F, ATF hits 304 F or AC head pressure exceeds 240 PSI. Certain DTCs will also cause the fan to operate at 100%, and turning on the AC will automatically add 10% to the fan speed. The solenoid will go bad at some point and when it does, often you'll hear a "whoosh" sound from the fan, like an aircraft taking off, along with noticeably reduced power. That will definitely set DTC's though.