Adjustable Pitch Fan - How to Adjust

[rv_safetyman]

The Shepherd charge air cooler issue continues.  Those of you following the saga, recall that I have installed a hydraulic fan.  It is 24 inches in diameter and is a Breeza fan made by London Fan company with adjustable pitch blades. 

On this trip, I finished wiring the two speed valve for the hydraulic motor.  I thought that applying 12V would speed up the fan.  Instead it slows it down.  That was a bummer, since I need to get more air flow.  It now looks like I will need to adjust the blade pitch to get more flow.  The location it is mounted in does not make that a fun job, but life is never easy.

When I got the fan from one of the great BCM readers, the pitch was set very close to the feathered position.  I increased that pitch to about 20*.  I have not found a document on how to adjust the blades.  I want to set the blades at the max pitch, but I can't find a document that tells me what that is.  I did find a sales document that mentions a range of 5* - 40* but that max pitch is not defined in any technical document I can find.

Anyone have any experience?

Jim

[luvrbus]

Jim, why don't you just do like Eagle did it they used 1 shroud and a 9 blade 32 inch fan.
Prevost has a CAC that goes on the outside of the radiator that well works for them.
I know you spent a lot cash trying to make it work but there comes a time when you need to cut your loses and go with a proven factory setup. 



good luck

[rv_safetyman]

Think I need to restate what the situation is. 

My radiator/engine cooling system is essentially stock (belt drive, aggressive fan, good shroud and rebuilt radiator) and works great!!!  Engine never gets over 192* under the worst conditions - even with the AC on.  With the engine offset to the driver's side, I can't put a charge air cooler in front of the radiator like the Prevost.  I have toyed with the idea of using the stock Eagle Series 60 set-up in (like Byron Pigg's), but both the radiator and the charge air cooler are very size compromised in my opinion. 

I had no choice but to put the charge air cooler on the passenger side where the AC condenser was.  Without the miter box, there is no way to put a belt drive over there like the original Eagle (other things in the way now anyway). 

My charge air cooler is pretty big and is new, so that is not the issue.  Getting air through it is the issue.  The electric fans I used (four) could not overcome the static pressure (area shrouded so that I am not fighting the engine radiator fan) .  I am sure the hydraulic fan will do a fine job when I make the pitch more aggressive. 

The issue is, how far can I go with the pitch (what is max effective pitch on these fans).  I have the number of the distributor (Nebraska), but I had hoped to get some real world experience from this group.

I should add that the present pitch keeps the air within a reasonable range for all but the long steep hills where you are putting out 90-100% of load for a long time.  That is with a pitch setting that looks to be about half of what I can use.  I suspect that the affect of the pitch is not linear, so I should be able to blow some pretty decent air after I reset the pitch.

Jim