Hey Guys.
I would Like to Change my mechanic Fan to an electric spal Fan. How strong should it be? Found one with 3400m3/ hour. Will that be enough? Its around 16 Inches tall.
How does the Fan Turn on? IS there a way to Put a Switch in the Radiator?
Would really appreciate any help

 

You should have a look at this Sticky post about aluminum rads and electric fan conversions.....lots of info to educate yourself there.

Aluminum radiators and related topics - CorvetteForum - Chevrolet Corvette Forum Discussion

 

What kind of car and more specifically which engine are we talking about here? I have 2 different Corvettes and 2 different radiator cooling philosophies. My 427 has 2- 11" SPAL Fans on a shroud and it is rated for 3168 CFM. My 1988 C4 has a big Puller fan behind the radiator with a shroud and it moves a lot of air (above 2500 cfm, I suspect). The C4 was equipped with the Auxiliary Cooling Fan that was on a switch and would turn on and off all on it's own. The primary (Puller) fan was controlled by ECU through a relay mounted on the firewall. The Auxiliary Cooling fan was a 16" (Pusher) Fan and it was in front of everything and Blew air into the Condenser and then the radiator.

The second system is bone stock and works very well. If you don't have an ECU then you can put a variety of different controllers to operate the cooling fans.

On my 1968 I use a DeRale Pulse Width Modulation Electric Fan Controller and it has been great. It will turn on the fans at whatever preset temp you put in, the BIG benefit is the PWM control of the fans allows you to start them up at 50% speed as as the engine continues to warm up the fans speeds will increase to keep the engine as cool as possible. This keeps the noise down to tolerable levels.

The most important thing is to get a good fit on the Radiator Shroud. It needs to cover pretty much the whole backside of the radiator to work most effectively. I used Rubber seals between the shroud and the radiator tubes. The shroud came with built in flaps that open and close depending on the car speed. When the fan is running they pull tight to the radiator sealing the shroud and forcing all the air to come through the radiator.

Here in the U.S. there are several alternatives to only using the later Corvette cooling equipment. There are a lot of people who swear some Ford cooling fans and shrouds work very well with little modification.

The more air you are to move is a good thing, the down side being noise unless you use a auto manufacturer's parts which are typically pretty quiet. My 1968's 427 Needs "all the cooling it can get" and the 1988 small block 350 just the normal amount of heat and this factory system works fine for the car.

 

I've tried a couple different styles of electric fans on my 77 through the years. So speaking with a great deal of experience. My C5 fans, (fans and shroud out of a C5 Corvette), work the very best of everything I have tryed, in every department. And cost me the least!
As per switching them there are numerous ways. A thermo switch in the intake manifold connected to a relay is generally the easiest.

 

my 71

fan relays

fan stats / trips

One trip is 170 deg, the other is 190. Has been on the car for 15k miles and 4 + years, no issues .

 

 

That's very helpful information! Thank you.

 

The single 16 inch puller fans are very loud, two 11 or 12 inch puller fans can be setup to come on independently and will cool very effectively. I used a Derale pwm controller, it was very expensive and didnt last very long. I use the Dakota Digital fan controller with bluetooth app for setup. It works great .

You definitely need a good shroud that will let air pass through little vent flaps on the highway while controlling airflow at slow vehicle speeds in traffic
You need to run a 100 amp alternator and upgrade the charge wire from the alternator to the starter. As well as the new wires with fuses and relays for the fans