TWO B&M 70268 Coolers In Series?

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Hi, If you tow the cruiser stays much cooler with an additional 70268 and it blocks very little air flow. Mike
 
I can bring more to your concerns than one might expect. There are numerous structural and aerodynamic variables. The most obvious/predictable factor is the direction of the fan. It is tempting to just swap the polarity of the power to change pusher/puller, but with this fan that will not have nominal results if that is done. The reason is that the fan blades are designed to be most efficient turning in the direction of the blade sweep (not pitch). This is a common design now in advance turboprops like the A400 and latest C-130 mod. This fan's direction (push or pull) must be done by flipping the rotor.

Structurally, this type of fan will benefit most whatever device its shroud is flush against; as a pusher against the condenser, or a puller on the back side of a radiator. In my installation, the fan is being tasked to do double duty. It will be most efficient at a pusher through the condenser. But its effectiveness as a "puller" for the transcooler is proportional to the cooler's distance from the fan; the closer the better. There is a happy medium, though, to be found in this installation. As a pusher for the condenser it needs to have some ambient temperature air draw. The transcooler is designed to benefit from ambient air flowing through AND around it. The 12" fan does just this, but providing more velocity at all times. The fan is also not pulling strictly transmission-heated air from the cooler; plenty of ambient temperature air flows around the transcooler. Hence my prediction that this will be a very effective configuration.

By the way, my background on airflow is from my background as a military pilot (retired). I refered to those "heavies," but that's not what I flew. With one exception (the A-10), what I flew was faster than a scalded-ass ape. :D

The airflow of an electronic fan is based on its ability to move air (pitch, quantity of blades, amperage/motor) and the air resistance.

A small electric fan isnt meant to make pressurized air, just move air. This is why just about every electric fan I've looked at (and I had major issues with the FJ40) is far better as a puller than a pusher CFM-wise.

Your fan is already in its lesser capable state as a pusher, then adding resistance (the cooler) in front of it.

If we were talking about something gas powered that can create pressure because the ability of the engine/motor powering the blades isnt all that dependent on the resistance of the blades/air around it. A small electric fan is going to be negatively impacted in situations where air flow becomes restricted.

Just trying to help here. While moving at speed there will be no issues as the electric fan should be off (as at speed it would become a restriction).
 
The airflow of an electronic fan is based on its ability to move air (pitch, quantity of blades, amperage/motor) and the air resistance.

A small electric fan isnt meant to make pressurized air, just move air. This is why just about every electric fan I've looked at (and I had major issues with the FJ40) is far better as a puller than a pusher CFM-wise.

Your fan is already in its lesser capable state as a pusher, then adding resistance (the cooler) in front of it.

If we were talking about something gas powered that can create pressure because the ability of the engine/motor powering the blades isnt all that dependent on the resistance of the blades/air around it. A small electric fan is going to be negatively impacted in situations where air flow becomes restricted.

Just trying to help here. While moving at speed there will be no issues as the electric fan should be off (as at speed it would become a restriction).

I appreciate the good intentions, but I can't see how your perspective applies in these applications...other than anecdotally. I'll offer my own anecdotal experience with the installed 12" fan. With the engine off, there is definitely a good flow through the condenser and radiator. Yes, testing it with the engine running it is impossible to measure its effectiveness...except with regards to the condenser. There is a reason that modern vehicles have a (pusher) condenser fan. A few years ago we started to notice that at long stops in idle in the summer, the A/C started getting too warm in our older Sequoia. There didn't seem to be a problem with the A/C itself. Turns out the condenser fan had weakened just enough to cause this. It was not visibly or aurally perceptible. I replaced it, and the problem went away and has stayed away. Do you doubt that such a fan would be beneficial in our Cruisers in such conditions? "Disadvantage" is tough to define, and maybe more so in practical terms. Effective is as effect does. We Cruiser drivers often find ourselves as the research engineers and test pilots. :)
 
No, I was not suggesting its innefectiveness on it's own. I'm saying its ability/CFM capacity will be lowered by sandwiching it between a condenser and a trans cooler.

It isnt able to produce pressure and it will have reduced capacity as it attempts to pull through the trans cooler when set up as a pusher (for the condenser).

Is there a modern day vehicle with that type of setup?
 
Congrats on your solution. I hope that it works out for you when the temperatures start to rise. I know you take this very seriously, since you are in Arizona and its a warmer climate.

I am not an expert in these areas for temperature control so its pretty cool to see what others have done and see if it works or not.

Who knows, maybe this is the right way to to do it and no one on MUD has thought of it (or shared it yet) or was too afraid to try it on their rig.

As I get deeper into these mods on the truck, I really appreciate it when a fellow Mudder goes off the beaten path and creates something new. Innovation I guess!
 
@toyotaspeed90 and @hygge...hi guys. Since we were talking about all this, I've completed my work and testing on this. I thought you'd like to see the dramatic results.


 

Users who are viewing this thread

Back
Top Bottom