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Topic: Wax Capsule Fan Controller Adjustment (Read 1089 times) previous topic - next topic

Wax Capsule Fan Controller Adjustment

Replacing my wax capsule hydraulic fan controller with a new version with a higher set point has been on my list for several years, probably ever since reading about the improvements by others such as Caflashbob.  My fans seemed like they were always on high at any reasonably warm engine temperature.  Any power taken from my relatively small Cat has a big effect on driveability, and the fans were taking a lot of it.  I was looking into purchasing a new controller last week and found one on Ebay for a good price that said it was adjustable up to 210deg.  David S suggested that maybe all of them are adjustable and, sure enough, my OEM controller is adjustable. 

I removed the Allen cap screw and inserted the same Allen wrench into the oil inside the controller to find the set screw at the bottom.  With no reference for how much adjustment was needed to bring it up to ~199deg, I turned it 1/4 turn counter clockwise and drove it a couple of hundred miles in 90+ deg heat.  My engine temp never got above 187deg and usually stayed between 180-185, which has always been normal for me.  Transmission temp also stayed normal.  I stopped at several points during the trip, including at the 187deg reading, and could not hear the fans without putting an ear to the radiator.  I used to be able to hear them after opening the front door.  They never ramped up to high speed.  Engine temps never rose above normal range.  And it made a HUGE difference in driveability.  I can now climb hills, with little or no speed change, that used to cost me 10 mph or more.  Acceleration from a full stop is much better.  I can now use the transmission economy mode where it was rarely used before.  I had too much generator time to confirm but I suspect there was a nice mileage boost as well.  It drives like a different bus now. 

I still don't know exactly what my high speed temperature set point is but will continue to monitor it and readjust if necessary.  So far there appears to be no downside to this adjustment.  It would have been worth buying the new controller ($250~$700 new?), which makes this the best "free" mod I've made.  Wish I'd known it was adjustable and done it years ago.

Re: Wax Capsule Fan Controller Adjustment

Reply #1 –
I just did a 700 mile trip to cali and back... hadnt really been able to test mine.. the way its set now ..on the way back to Las Vegas on the back of bakers grade.. 210 hottest with my foot in it...it was hot out sunday.. so far that works for me and will keep it set at this point.. I did notice on the way back my mpg went up.. averaged 9 mpg in a few places and even 11 at one point.. so far I am happy. it was cheap upgrade so it paid for itself this last trip

Re: Wax Capsule Fan Controller Adjustment

Reply #2 –
See I wasn't crazy was I?

Re: Wax Capsule Fan Controller Adjustment

Reply #3 –
A remote reading laser tachometer would be useful for this testing.

Re: Wax Capsule Fan Controller Adjustment

Reply #4 –
Quote from: krush –
A remote reading laser tachometer would be useful for this testing.
Harbor freight has them cheap.. that's how I set mine to handle the manifold temps at lower speeds.

Re: Wax Capsule Fan Controller Adjustment

Reply #7 –
But it's the good kind of crazy.  We are upgrading and testing out prepper power alternatives

Even paranoids have enemies

Re: Wax Capsule Fan Controller Adjustment

Reply #9 –
Just got this information from MFG on the wax valve-- According to them the inside screw has nothing to do with changing temperature
Chris
Picture didn't transfer I'll try again

Re: Wax Capsule Fan Controller Adjustment

Reply #10 –
wax valve information
Chris

Re: Wax Capsule Fan Controller Adjustment

Reply #11 –
Maybe I'm not understanding the difference between adjusting the temperature and regulating the pressure at certain temperatures, as their reply says.

"This adjuster is to regulate the pressure at certain temperature as it will open or close the gap on the bypass."

Seems like semantics to me, and I believe turning the screw has made a definite difference.  I'll be interested to see if others have similar results.

Re: Wax Capsule Fan Controller Adjustment

Reply #12 –
The valve I installed has a set point of 199 degree F. (93C)-- is that running too hot?  I haven't been able to get temp over about 190 according to laser checker but vmspc said temp was 187  fan speeds also changed with engine RPM at 600 engine fan speed was
at 580 at 800 engine fan speed was 1050 at 1200 engine fan speed was 1750.  I have not seen where others have had different fan speeds with different engine rpm. "I'm confused"
Thanks for any and all guidance
Chris

Re: Wax Capsule Fan Controller Adjustment

Reply #13 –
199 is the set point that you want.  The stock version was set much lower than that...like 185?  I don't know about the fan speeds but I think you're good to go.

Re: Wax Capsule Fan Controller Adjustment

Reply #14 –
Not sure I understand it.. The adjustment adjusted the fan coming on earlier.. with temps or whatever .. it still came on at 185 instead of the 199. So not sure what they are saying.

Also when I turned it down I had a problem with the fan turning so I added the needle valve.. to fix that issue and make it adjustable to where I needed it.

Re: Wax Capsule Fan Controller Adjustment

Reply #15 –
The dynamatic fan controller starts at low speed at 15 degrees below its "set point"

So at 184 the wax capsule starts ramping up the fan speed it controls on a straight line until it hits it maximum internal fluid flow setting of 199.

Separate from the hydraulic pumps output which as you have seen in rpm controlled.

Both systems can and do work in tandem. 

Lower rpm engine speed and coolant heating cause the fans speed to increase,

Or at higher rpm the fan might not be needed  to add as much input.

As you have seen it works the same as the oem 185 max speed unit.

Foretravel may not have been aware of the 170 F. start of the fan speeds ramp up.  The older systems had a low/high not variable speed.

The 185 was correct.  Except as the end of the low fan speed setting and then ramp up to the 199.

Stands to reason now that we see the 184/199 works perfectly


Thanks to VPMS that showed a large jump of RMPG for no apparent reason.

Turns out after a years long elimination of other draws that the fan was the culprit.

Bob Rozen verified my results a few years ago.

Glad it works well.  No heating issues and more power and mpg.

Which are both good things.

I added  a resonator to max the power and mpg

And added solar to kick off the alternators load while driving during daylight after the batteries are topped off and to work with the battery auto combiner to keep both banks up in storage outdoors

If you add the ME-MW-W wireless internet connection it sends the entire systems status to a central magnum website every 30 seconds automatically.

Shows faults and auto gen run info.

Requires a constant on internet connection to send it's info out automatically.

2.5 meg transfer rate capable. Dated 2011 manual

Re: Wax Capsule Fan Controller Adjustment

Reply #16 –
Quote from: bdale –
Maybe I'm not understanding the difference between adjusting the temperature and regulating the pressure at certain temperatures, as their reply says.

"This adjuster is to regulate the pressure at certain temperature as it will open or close the gap on the bypass."

Seems like semantics to me, and I believe turning the screw has made a definite difference.  I'll be interested to see if others have similar results.



Quite likely they are two different things:

1. Full open temperature (per response above, sounds like NOT adustable.

2.  PSI to the fans at full opening temperature-- per this thread sounds like it is adjustable.  Not sure I would want to fool with this one, unless you NEVER encounter a condition where fan speed on high (engine coolant temperature to wax capsule set temperature) and still climbing.

Re: Wax Capsule Fan Controller Adjustment

Reply #17 –
Quote from: wolfe10 –
Quite likely they are two different things:

1. Full open temperature (per response above, sounds like NOT adustable.

2.  PSI to the fans at full opening temperature-- per this thread sounds like it is adjustable.  Not sure I would want to fool with this one, unless you NEVER encounter a condition where fan speed on high (engine coolant temperature to wax capsule set temperature) and still climbing.


Understood and agreed.  Replacing the OEM with a new controller set at 199 would be the better option but for now the adjustment is working great.  Driving in Texas heat hasn't sent the engine over 200deg yet.  Maybe mountain or other conditions would.  I'll continue to monitor it closely and readjust if necessary while looking for a deal on a 199deg replacement.

Re: Wax Capsule Fan Controller Adjustment

Reply #18 –
according to chart he sent the part number dictates the temperature set point.  Last 3 numbers on mine is 857 which is for 93C or 199F
Chris

Re: Wax Capsule Fan Controller Adjustment

Reply #19 –
what should the fans be turning when on high speed?
Chris