Electric fan conversion

[L31MaxExpress]

Goes both ways champ. I don’t see a reason to crap on what some dude wants to do to his truck despite how much you don’t like what he’s doing.


Then why did the entire auto industry switch to electric fans?
How come everyone except you is trying to fit one in their classic car for better cooling? If it were a step backwards then it wouldn’t be a viable option. Notice no one swaps in a clutch fan.

So?

Rant over.

The entire industry did not switch to them. GM still uses them, Ram uses them, Nissan still uses them, Ford still uses them.

Electric fans are not better cooling in any way or shape. My ac works better with a clutch fan than it did with electric fans, pointing to the clutch fan pulling more cfm.

People have a tendency to tack on electric fans when space prohibits using the OE style shroud. Case in point I tuned a 6.0L in a 2 door Tahoe that kept running hot. Switched it back to the stock shroud and the L31 tow package fan and you can not make that Tahoe run hotter than 200F now. That truck had the 34" wide radiator and later model GM fans as well like my van did.

When you drive a road that is 50+ miles between towns and it takes 2-3 hours for a tow truck to arrive, it may be of concern how long the electrical system will continue to run that vehicle in the event of a charging system failure. It is the difference between being stuck on the side of the road or making it to the auto parts store in the next town.

Years ago I bought in to the hype of the Ford Crown Victoria electric fans. I put one on my G20 van. After 3 dyno pulls on a 100F day it was spewing boiling coolant into the overflow reservoir. I put a clutch fan back on it and saw very little in the way of power and no change in fuel mileage. I later tried the GM dual fans on the Express and experienced the same results.

The last couple of weeks the Small Block and Big Block groups I follow have had multiple people posting about cooling issues from electric fan conversions.

 

[OutlawDrifter]

People have a tendency to tack on electric fans when space prohibits using the OE style shroud. Case in point I tuned a 6.0L in a 2 door Tahoe that kept running hot. Switched it back to the stock shroud and the L31 tow package fan and you can not make that Tahoe run hotter than 200F now. That truck had the 34" wide radiator and later model GM fans as well like my van did.

I have 6.0L's in both my Z28 and my '49 GMC...neither has a large radiator or grille opening area. Both run electric fans(Z28 stock fan/radiator, ,'49 aftermarket for both), and both can sit and idle in 100* 70%+ humidity temps just fine. The fan in the '49 is a 2-speed and has never kicked on the high side other than when we commanded it to when tuning it.

Niether is candidate for a clutch fan, and I highly doubt either would benefit. My Suburban has a clutch fan and the factory aux. electric, I would never change the clutch fan out for an electric, but it's also a 3/4t rig that I tow with. I'm most certain it would produce lower AC vent temps at idle low speed with a nice dual OEM electric setup, but it's not worth the added expense. Another example that is different than your findings, my Tundra has a HD cooling clutch fan. On super hot days after the engine bay has heat soaked, I can still hear the fan running while on the highway....this is completely unnecessary and costs me .5 MPG at the pumps. I track every tank and as soon as the hot summer weather hits, (I run my AC when it gets in the mid-70s because I don't like "hot" weather ), my mileage goes down. When its 85* or less outside, the fan never runs on the highway, above 90* its miles out of town before it finally free wheels, and this is at 68ish mph. It also eats HP, you can tell with a 4.7l V8...definitely a large parasitic draw.

There is no 1 size fits all answer. I'm glad that a clutch fan works out for your vehicles, but there are just as many success stories with electric as the horror stories you're promoting.

 

[Erik the Awful]

You do you, there's no significant difference.

I've had both a factory clutch fan and an electric fan on WCJr. Both failed. An electric fan might free up a couple horsepower, but honestly, my butt-dyno doesn't even notice the drag of a clutch fan. I really liked ditching the clutch fan on my RX-7 for an electric because it revved like a chainsaw. My race car has electric fans partly because it was easier than trying to build a shroud for a non-factory clutch fan on a Cadillac engine for a Chevy radiator in a Jaguar chassis.

Just make sure you have a fan on it and be happy.

 

[L31MaxExpress]

I have 6.0L's in both my Z28 and my '49 GMC...neither has a large radiator or grille opening area. Both run electric fans(Z28 stock fan/radiator, ,'49 aftermarket for both), and both can sit and idle in 100* 70%+ humidity temps just fine. The fan in the '49 is a 2-speed and has never kicked on the high side other than when we commanded it to when tuning it.

Niether is candidate for a clutch fan, and I highly doubt either would benefit. My Suburban has a clutch fan and the factory aux. electric, I would never change the clutch fan out for an electric, but it's also a 3/4t rig that I tow with. I'm most certain it would produce lower AC vent temps at idle low speed with a nice dual OEM electric setup, but it's not worth the added expense. Another example that is different than your findings, my Tundra has a HD cooling clutch fan. On super hot days after the engine bay has heat soaked, I can still hear the fan running while on the highway....this is completely unnecessary and costs me .5 MPG at the pumps. I track every tank and as soon as the hot summer weather hits, (I run my AC when it gets in the mid-70s because I don't like "hot" weather ), my mileage goes down. When its 85* or less outside, the fan never runs on the highway, above 90* its miles out of town before it finally free wheels, and this is at 68ish mph. It also eats HP, you can tell with a 4.7l V8...definitely a large parasitic draw.

There is no 1 size fits all answer. I'm glad that a clutch fan works out for your vehicles, but there are just as many success stories with electric as the horror stories you're promoting.

Idle cooling is not where electrics have caused me issue. It is exactly where you say you hear your clutch fan spooled up. At 75-80 mph my clutch fan still cycles on and off. The temps would climb, the electrics would turn on, then the electric fans would be screaming on high, drawing 50 amps and the thing would still overheat.. In the same conditions the clutch fan engages and the temp gauge drops like a rock.

My idle ac temps stay about 40F, they dropped from 140F to 50F in 1 mile and to 40F in 2 miles in 100F and 48% humidity a couple of days ago.

 

[GoToGuy]

I'm not sure but is the OP taking about single electric fan GM added for extra cooling at low vehicle speed and add extra effeciancy to condenser operation?
You don't have to be a rocket scientist to know a pair of fans, of the correct, for engine size, flow volume with ducting, shrouding would be more efficient and effective. More cooling potential at low, or no vehicle speed. And no parasite drag on engine power at high speed due to ram air effect cooling.

 

[b454rat]

I put a Taurus fan in my 79 Malibu with a 454. I put the biggest radiator that would fit, small compared to what these trucks come with, didn't have a shroud, other than the one that the fan had. They were a 2-speed fan, but wired it up on a switch to the hi side. It would be over 200 sitting there at idle, flick it on and could watch the temp go down. Any movement at all, it was off and let the air flow through the radiator. It never got hot, boiled over or had issues running hot. It was 10:1, iron headed, dark blue car. And if you ever saw a big block in a G body you know there isn't alot of room. I wouldn't hesitate to run another fan, but would have to be an OEM, not paying what aftermarket crap is.....

 

[L31MaxExpress]

I'm not sure but is the OP taking about single electric fan GM added for extra cooling at low vehicle speed and add extra effeciancy to condenser operation?
You don't have to be a rocket scientist to know a pair of fans, of the correct, for engine size, flow volume with ducting, shrouding would be more efficient and effective. More cooling potential at low, or no vehicle speed. And no parasite drag on engine power at high speed due to ram air effect cooling.

Does not take a rocket scientist to figure out that blade diameter, chord and pitch can be changed to get more airflow and that a properly functioning clutch allows the fan to practically free spin when not needed. Also ram air on some vehicles is no enough to adequately keep them cool and some form of fan will be necessary even at 60+ MPH. The more load your engine sees at cruising speed the harder it will be to cool. A lightweight car that only requires 30 hp to cruise around at 60 mph will require less CFM than a motorhome that requires say 150 hp at the same speed.

The fans I had on my van cool a 6.0L in a GM 1500 truck but GM did not use electric fans in an 8 lug truck or an Express/Savanna for good reason.

 

[eXo0us]

At 75-80 mph my clutch fan still cycles on and off. The temps would climb, the electrics would turn on, then the electric fans would be screaming on high, drawing 50 amps and the thing would still overheat.. In the same conditions the clutch fan engages and the temp gauge drops like a rock.

In my GM P32 based RV I built baffles to direct the air into the radiator.
Basically a giant ram air scope for the Rad. As soon as drive 45mph+ the incoming air is enough to cool and the clutch fan doesn't engage anymore.

It essentially only engages when I rev up a hill at low speeds. Or at idle in stop and go traffic.

So my opinion on the topic is:
When you design the aerodynamic of the vehicle right - you shouldn't need clutch fan. Electric should be fine.

 

[GoToGuy]

And yet Ford installed an electric fan on any Crown Vic ordered with Law Enforcement option, instead of clutch fan.
Hmm..

 

[Orpedcrow]

I will be purchasing a fan relay wiring harness

Make sure you get something reputable, I’ve had terrible experiences with Hayden products. So much so that I’m going back to a mechanical fan.

There’s a sticky thread about mark VIII fans somewhere in here. He had a cool setup using a bmw temp switch and Volvo relay pack.

I’ll change the thermostat to a 170 as well.

I don’t know that this will be a benefit. Our trucks usually have better efficiency with a 195*