Pusher Fans

Yes air should flow to the rear, you can hold a sheet of paper in front of the front grill while the fan is on. If it sucks up against the grill then it is correct. If it blows away then reverse the motor wires.

As I understand, The blades must turn in the direction of the arrow, regardless of polarity.

If you want to reverse the direction, as shown by the arrow, pull the fan blade from the motor and flip the fan blade. Now you should see the arrow in the opposite direction, Set the polarity according to the arrow. If checking air flow direction, be very careful powering the motor/fan while holding. A mismatch of of the arrow and polarity will still provide push or pull air but not optimized.

Indy, yes this concept is true...However, these fan blades appear to be completely symetrical from one side to the other, so i chose to leave them in place.

Thanks for the confirmation.

The fan problem in addition to the wrong thermostat, in addition to air in the system has made for some frustrating evenings as I try to get 4507 out on the the first road test! Now, it seems to idle for long periods of time and stay under 200 in about 85 degree ambient temps.

Blue, Do you have the information on how to bleed air from system?

What thermostat is in the car?

Are the fans running off the OEM relays/system?

Original radiator?

cant get my image to come up, but I THINK I have the Hall pheonix radiator and the Meriah Fans. They are on relays, whether they are the correct ones...remains unknown. I have a mod-podge of information i have collected from this site on how to bleed/burp the air out of the system.

I pulled a Windsor 160 out of the block, replaced it with a 190 cleveland thermostat and added the brass orifice plate which was missing. Now the problem has been with the fans, and figuring out how i am going to change these hoses...which i would like to do before i get too far.

When I used to have Meriah fans on my car, one thing I found out while testing airflow was you must have at least a one(1) inch space between the fan blade and the front of the radiator fins. This Is about the maximum distance you can pull the fan back in the bracket because of the limited space.

When you have the fans too close, a lot of the airflow bounces back on the tightly spaced fins of the 7 core radiator. Mine only had a 5 core brass(also made by Hall) but also had the same effect with the fan blades too close.

I recently installed Mariah fans on my car, too. I remember having to check the direction of fan rotation by wiring it directly to the battery. The result was that the red wire coming out of the fan motor, conventionally the +Battery wire, had to be affixed to ground. Once I reversed the motors polarity the fans rotated the correct direction, pushing air through the radiator towards the back of the car.

Blue 72,

In your original post you mentioned wanting the fans to come on at the same time. My understanding is that the fans are designed to turn on in a staged manner. There are two temperature sensors in the radiator to accomplish this staged function.

Is there an advantage to this, other than drawing amps off the battery? It would seem desirable to me to have the fans turn on and cool the fluid as much as possible via airflow before that coolant returns to the engine.

If they are designed that way than I suppose I dont have a "problem" just something that I might re-design as a side project.

There are contributors more knowledgeable than me on this subject, but I am running a Big Block with what appears to be the same radiator/fan setup as you. I have not experienced any extended idle temperature issue using the conventional staged fan operation. I recently was stuck in a traffic jam on a 90 degree day and the temps stayed well in-check. Both fans were running, as expected when things got hot, but the staged fans seemed to maintain a consistant gauge temp. One caveat: I am using a thermo-controlled electric water pump.

It would be very easy to wire the fan relays to a single temperature sensor, but I don't know of any advantage in doing so.

I would recommend you take a look at Pantera Electronics, Radiator Fan Controller. Jon Haas is an automotive engineer and fellow Pantera owner.

The Radiator Fan Controller isolates the fans from the Pantera electrical system.
It decreases and increases the fan speed as needed. This is truly a work of art.

http://www.pantera-electronics.com/rfc.htm

Also take a look at the ATO Fuse Panel. This is a “plug & play” replacement. It eliminated electrical issues I struggled with for years.

http://www.pantera-electronics.com/fuse%20panel.htm

The original radiators were set up as two pass with the flow across the front and retuning across the rear. The temperature sensors were thus both reading the leaving water temperature and truly staged the fans. The improved radiator changed the tank baffle from vertical to horizontal thus moving water through the bottom half and returning across the upper half. The sensors now read leaving water temp on the top pass and engine temperature on the bottom half. If you are running a 180 stat then the entering water will be at 180 or above regardless of how well the radiator is working so that sensor is essentially useless causing the fan to run almost constantly. I and others control the fans based on the temperature of the water leaving the radiator and this has worked well for me for 20 years. Just my opinion and I know there will be some who feel strongly about other methods.
Forest