Replace mechanical fan with electric fan?

[Hahn007]

I am considering replacing the mechanical engine cooling fan with an electric fan.
Chassis is 1985 P30 454 CID.



A few questions:

   
• Has anybody out there does this already?
• Any idea of CFM requirements?
• Any recommendations for reliable brand names?
• OEM from wrecking yard vs new aftermarket?
• One large fan or two medium fans?

Thanks in advance for your responses,
Chris

[MotorPro]

Most p-30s have both mechanical and electric fans.

[TripleJ]

I did what you are describing.  When I had the front of my engine disassembled, I thought it would be worth it to replace the engine fan with electric fans.  It will reduce weight/prolong the life of the water pump bearing, give me more space to work on the front of the engine/change belts/etc., I can run the fans on max even while idling in traffic, more airflow around the engine bay with the mech fan shroud removed, plus some other reasons I can’t remember right now.

I opted for a factory replacement part instead of an aftermarket fan.  I thought a factory type part might be designed to be a little more reliable in the long run.  The fans I chose were based on packaging rather than cfm requirements. Altho by my uneducated estimate, the tight clearance-less packaging of modern engines, where the engine is pretty much a little insulated heating element with ONLY the radiator providing ANY heat exchange... I figured I could be flexible on actual cfm...

I wanted a dual fan, puller configuration, with a built in shroud that would cover the majority of my radiator surface.  I read that having a complete fan shroud is more important that having super hi-tone fans, that is - smaller fans properly shrouded will cool better than larger more powerful fans with no shroud.

Lastly, I am cheap.

Anyhow, my fans are the dual fan replacement assembly from about a 2003 Chevy Impala.  I bought the assembly new from Oreillys for about $100.  I made some efforts to find used parts, but the easiest way was to browse their shelf for the size assembly I was looking for, plus people around here seem to think their used fan assemblies are made of gold.  The guys at Oreillys know me and my RV and are pretty cool about letting me find stuff when the books/computers lead to a dead end.  It took quite a bit of modification â€" more than I wanted to do â€" in order to fit it like I wanted, but that’s the way it goes retrofitting…  The fan assembly in the factory vehicle is capable of low/high speed.  I had a schematic at one point that showed the fans running in series for low speed, then switching to their own dedicated circuit for high speed.  Right now I only operate them on high speed or fan off.  At some point I will wire them for low/hi/off.

I used inexpensive fan controllers from amazon (like $15 cheap). They are adjustable, use an air probe and are annoyingly cheap.  However they have functioned for the past thousand or so miles.  I have two controllers mounted next to each other. Only one controller is connected, controlling both fans.  I figure if I start having problems I can just swap the wires over to the other controller and make it wherever I’m going OR it would be quite easy to hard wire the fans permanently on in a emergency.

The controller switches the fans through separate 30 amp relays.  I bought a pile of 30amp relays from amazon for like $10 because the Oreillys price pre relay was ridiculous. 

So far I haven’t had any close calls or temperature emergencies, but I don’t think Ive pushed my engine very hard yet.  The biggest pull Ive had to make is the Zilwaukee bridge, but I doubt that it is ½ mile long.  My BIGGEST complaint is that the cheap fan controllers I bought seem inconsistent.  Sometimes they come on and never seem to shut off, sometimes they cycle like normal, sometimes they are running when I key-ON after sitting for a long period where the engine should be mostly cool.  I intend to get a better quality fan controller that uses a probe into the coolant in the near future. 

[TripleJ]

Not too easy to see, but you might get the idea.

Here is kind of a shot from atop the engine looking down.  Although still awkward, changing belts is much easier now



This is why there is no pusher fans on my P30


Im certain I have better pics, but I guess I didn't upload the into my bucket yet

[GONMAD]

Very nice! Now you will never have to listen to that NOISY Clutch Fan again! You're way ahead of the game by the use of an aluminum radiator, not only saving precious weight but can't be beat when the heat is on under load. As far as the controller quality, get the best & maybe two ( one for backup. I used a Robertshaw thermostat from a Cacilware coffee maker to control the cooling system on one of my Nomad builds. The only change I made to it was to flip the contacts opposite the way they came & it worked great. These thermostats handle the heating element in the coffee maker tanks, the same as a home electric water heater & will do the job. Although the relays are the way to supply the power putting less strain on the components. I'll dig up the pics & post them soon. I could adjust the engine temperature from the dashboard. Once again nice job.     GONMAD

[Hahn007]

Thanks for the replies so far, especially the pics.

[eXodus]

electric fans are the way to go. sucking power only when needed, and provide cooling when engine is not reving high but is on high stress like stop and go an a hill.


converted all my cars to electric fans, always saved a ton of fuel and noise.