Electric fan or Mechanical. Which cools better?

in my many years of reading HOT ROD magazines all the articles on cooling seemed to say mechanical fans are the way to go.

of course over the past few years "tech" articles mostly cover installing products from various advertisers, so the results may be different these days.

 

In a properly designed and built cooling SYSTEM, a quality fan of either type will do the job.
The problem is, if the SYSTEM is not able to handle it's job neither will fix it.
The original post doesn't mention this, but the update does.
BTW, I prefer a good thermal clutch fan unless ther eis simply no room. It follows the KISS rule.

 

Exactly. Traditional hot rod stuff here, not street rod(street rod-old body with modern **** underneath). Even my 2011 truck has a mechanical fan, works fine. MY '65 Buick has drum brake and mech fan-works fine too.

 

Lame excuse for poor planning. How'd they do it before electric plastic fans came around?

 

Mechanical Fans don't break down.

 

Check:

1 - Fan Shroud (you must have one & seated agaist the rad.)
2 - Thermostat (Cost $4, change it)
3 - Timing
4 - System Flush
5 - Water Pump
6 - Catalatic convertor (Offen overlooked. Clogged will cause it to overheating)

 

Come to think of it, 100,000+ miles, new Cat.

 

Which one cools better? The one that moves the most air thru the rad when you need it.

 

1) There were pretty much as many if not more *original* pre-65 hot rods out there with electric fans than with air conditioning (the latter number being near-zero)

2) Of course, they didn't have fancy molded nylon-fiber-reinforced plastic shrouds, so maybe you ought to start bending some aluminum especially if you're running a pusher setup 427 Cobra style.

3) Engine-driven fans can be more effective just based on the sheer power available

4) Fans are needed at very slow speeds (when an engine-driven fan is semi-useless) and at slow-to-medium speeds but very high loads (heavy towing uphill) and don't forget that at higher al***udes the same reduction in air density that affects air-fuel ratio also affects cooling.

5) In the first of those cases an engine-driven fan is nearly useless unless it is VERY large and well-shrouded

6) A very large engine-driven fan is a HUUUUUge power drain at higher RPMs unless clutched but a big, modern, nine-blade plastic fan with a thermostatic clutch isn't a whole lot more 'traditional' than an electric.

7) Old Detroit unshrouded stamped-steel X-fans were slighly less effective than standing in front of the radiator and urinating, but of course it's difficult to find someone to do that at speed and the side-effects for the driver, particularly in a roadster, are an even greater limitation. It might, however, be fairly traditional if the guy on the bumper is drinking PBR.

8) Back in the day the 'traditional' equivalent of the electric fan was the canvas bag dripping in front of the radiator. Usually filled with water, not PBR. Sometimes Schlitz.

9) Engine-driven and electric fans each have their own noise-level problems (primarily an issue for the factory NVH engineers) mostly a function of fan-blade speed.

10) Because of this you also see very steeply-pitched slow-speed fans driven by hydraulic motors on some high-end late-model hardware.

 

Mechanical fans do cool better and look correct on a hot rod,,I've used electric fans when I didn't have room for a Mechanical,,and as
Tommy said,,poor planning on my part.

If you like the electric fan use it,,but the are still ugly in my book! HRP

 

One thing that hasn't been mentioned (I think) is that with mechanical components, fan and water pump, you are affected by motor rpm, particularly the water pump. The higher the motor rpm's the more water you will be moving through the block and radiator. I know you will be limited by the thermostat choke point, but still there is a difference. While sitting idleing, you are not moving as much water through the system as at a higher rpm. An electric water pump allows water to flow at at set rate no matter what rpm the motor is at. I guess my view on "old school" hot rodding was to get the most hp out of the set up I was running. With the mechanical fan (not so much with a clutch) and water pump, you are using motor hp to turn them.

 

Gator,
I'm with you on this. Our 57 Chevy truck has a stock 350, with a stone stock radiator and 7 lb cap, 5 blade mechanical fan with no shroud that sits two inches away from the core and it never goes over 190 in traffic with a mechanical SW temp guage

 

A few years ago I contacted Vintage Air in reference to a fan and A/C questions. The technician,keep in mind he sells electric fans, stated there is NO electric fan that in its's overall efficiency is as good as a mechanical fan. The big reason for the use of is,space and FWD. If you notice now a days when you see electric fans in late model RWD trucks they are huge. We generally are not lucky enough in old hot rods to have that much space.

 

There's different ways to contribute to cooling depending on the car design. Are you working on the shoebox in your avatar?

I use a header panel to strengthen the hood latch and channel all incoming air through the radiator instead of losing any up and over.

I experimented with a 3,000 cfm spiral blade Spal repositioning both push and pull, but got the best results from a 7 blade clutch fan and full shroud.

Full inner fenderwells and even little things like rubber caps over the A arms keep things flowing through for best cooling.

Every little bit helps...................

 

Would love to put a clutch fan on wifes 50 Chevy but only have 2 3/4 inch between radiator and nose of water pump pulley. Have an unknown size (CFM) 16" electric offset on the rad now which works for the most part but will allow the ZZ3 to heat up on extended low speed stuff. Will be heading to Eastern WA. in a couple weeks where temps will be much higher and plan to use the A/C. Should be interesting.

Looking at the Sidewinder but it is in redesign right now with a "new more reliable motor" and probably won't be available for another couple of months.

Expensive solution but if it works I'll be happy.

 

I'm with you on this. Any kind of parisitic loss is bad in my book. Another thing to keep in mind is how fast you plan to spin your motor. Mine see's 7200 PRM's and not to many fans are even rated for that speed.
As for the guy that siad machanicle fans don't brake, I can ***ure you thay do. A cracked fan blade or a failed fan clutch can cause a whole lot of damage.

 

I gotta agree with the boss here:
Quote:
Originally Posted by Ryan
Electric fans ****.



Electric fans are ugly.
Electric fans are ugly.
Electric fans are ugly.
Electric fans are ugly.
Get it yet?
Brand new Mustangs are real fast and cheap. But this place is about traditional hot rods, not going fast as possible as cheap as possible with plastic ****. How ****ing complicated is it?

 

Well, to the OP, based on the previous intellectual answer, a mechanical fan cools better because electric fans are ugly. Disc brakes **** *** too because, well, they also are ugly. Dont even get me started on the HEI, man those things are really ugly!

 

****in' A right they are! This is '65 back, not 70s smog rods!

P.S. Of all the cars I've owned, the only fan problems have been electric fans.

P.S.S. I don't like electric fans.

 

all I know for certain is that this one is a pain in the ****. wouldn't be so bad in a fenderless HOT ROD but it is a pain in a big truck.

 

Disc brakes are an ignorant arguement here, so quit trying to be bad-***es by bringing them up.

This thread is yet another about electric fans. Electric fans don't fit the HAMB. Amazing how few people actually understand what this internet forum is all about.

Looka at it as a "don't ask, don't tell" scenario. Run whatever fan you prefer- but don't argue about them here. Pretty simple to figure out- you'd think.

 

Good point. Why do I try to argue? If they don't get it yet, I guess they won't.

 

And the original question? Which cools better? An electric motor the size of your fist, or one spun by a 200+ C.I. V-8? What do you think?

 

I've run both, but prefer a mechanical fan if room allows. If the fan does not show with the hood shut, the look of an electric is not a big problem for me. If the engine is exposed, then an electrical fan looks out of place. The other thing about an electrical fan, no matter what the application, is the noise (sounds like a shop vac, and detracts from the tone of the engine).