Engine Dehumidifier ideas / solutions

[Stephen]

This is to split my "..hosed CAM.." thread in vintage as the topic has dug up some interesting fodder on engine de-humidifiers as perhaps part of some mitigation to engine aspects of extended airframe ground time/humid environments. 

By way of context, this came out of discussions on dealing what perhaps may be higher susceptibility to lifter corrosion in the lifter/CAM engagement of the IO360 engines.... or rephrased: "maybe if I manage ground engine humidity,  it could help avoid having to pay for an early overhaul or IRAN". 

Here is what I dug up on the humidifier front:

DIY with desiccant media:

http://www.barkeraircraft.com/EngineDryerSportAvi.pdf   

AC condenser engine dryer. One MS'r indicated integrating the system power with a humidity switch...cool.

http://www.flyingsafer.com/p-n-2065.html 

 

 

[Bryan]

I have a TCM engine, but still the same concerns.  Just about every flight that I return to my hanger, I open the oil cap and let the crankcase breathe out the steam while I push-back and clean the plane up. I do not do this when remote. I am unsure it does anything but it cannot hurt as long as I cover it back up before leaving for the day.  I also acquiredan "Engine Saver" on the cheap that de-humidifies the engine thru the breather tube.  I have used it and it seems to do what it was designed to do: pump low humid air into the engine to "dry" the engine from normal condensation generated from combustion.  Again... I figure it cannot hurt.

[Seth]

Stephen-

Byron has created a DIY dehumidifier he uses with his and his wife Becca's M20J.  Byron or Becca, either of you two around?

-Seth  

[Andy95W]

4 hours ago, Seth said:

Stephen-

Byron has created a DIY dehumidifier he uses with his and his wife Becca's M20J.  Byron or Becca, either of you two around?

-Seth  

@jetdriven

[jetdriven]

We bought a Tanis engine dehydrator and then put orange and white beads in it because the blue ones are toxic. Cobalt.

Then I modified it with the humidity sensor and switch. Because the stock configuration it runs all the time and depletes the beads quickly.

Edited June 17, 2019 by jetdriven

[pwnel]

I've also recently been looking at the Black Max.  Still need to determine if it will work with the TSIO 360.  Whereas they mention that most breather hoses has an ice hole a little way up and that you need to stick the Black Max hose high up enough to go beyond that hole - the TSIO 360 has it significantly high up - possibly too far up to work with the Black Max.  And you can't get to that hole without taking the bottom cowling off.  

If you don't deal with that, the dehumidified air is just going to leak out.  

 

 

[slowflyin]

1 hour ago, pwnel said:

I've also recently been looking at the Black Max.  Still need to determine if it will work with the TSIO 360.  Whereas they mention that most breather hoses has an ice hole a little way up and that you need to stick the Black Max hose high up enough to go beyond that hole - the TSIO 360 has it significantly high up - possibly too far up to work with the Black Max.  And you can't get to that hole without taking the bottom cowling off.  

If you don't deal with that, the dehumidified air is just going to leak out.  

 

 

I use the black max on several different airframes and always place the tube and rubber stopper in the dip stick hole.   Using the cc vent results in an oily mess.  Humidistat shows excellent results.

[pwnel]

19 hours ago, slowflyin said:

I use the black max on several different airframes and always place the tube and rubber stopper in the dip stick hole.   Using the cc vent results in an oily mess.  Humidistat shows excellent results.

Thanks, but help me out here - given the breather hose and the hole I show above (similar on all K models I believe), how would you prevent the dehumidified air from  just venting out of the breather without properly circulating around the engine?

[jetdriven]

I put a thin piece of Nashua aluminum contractors tape over that hole. But before I did I put thumb prints all over the bottom half of the tape so that’s the part that goes over the hole so it doesn’t obstruct all but it does shielded by a lot

[slowflyin]

8 minutes ago, pwnel said:

Thanks, but help me out here - given the breather hose and the hole I show above (similar on all K models I believe), how would you prevent the dehumidified air from  just venting out of the breather without properly circulating around the engine?

Air does exit the breather.  Initially, very moist air is pushed out.  Actually, I'm sure dry air from the pump is  mixing with the moist air but after a very short time the humidity levels are very low within the engine.   You end up with dry air pumping in and dry air coming out.   I tried it both ways and after measuring the internal moisture levels I couldn't see any difference.  In practice the levels dropped quicker through the oil filler tube.  I assume the air exchange was quicker with zero backpressure.   For clarification, I measured moisture coming out the breather tube and by inserting a sensor through the filler neck as deep as it would go.     In the end I determined the unit was pumping a very large volume (over time) of very dry air into the engine.   

[pwnel]

3 hours ago, slowflyin said:

Air does exit the breather.  Initially, very moist air is pushed out.  Actually, I'm sure dry air from the pump is  mixing with the moist air but after a very short time the humidity levels are very low within the engine.   You end up with dry air pumping in and dry air coming out.   I tried it both ways and after measuring the internal moisture levels I couldn't see any difference.  In practice the levels dropped quicker through the oil filler tube.  I assume the air exchange was quicker with zero backpressure.   For clarification, I measured moisture coming out the breather tube and by inserting a sensor through the filler neck as deep as it would go.     In the end I determined the unit was pumping a very large volume (over time) of very dry air into the engine.   

Thanks for that clarification.  I really enjoyed reading the entire analysis Black Max posts on their website and which originally appeared in Twin Cessna Flyer - (here for interested folks).  That really convinced me of the value.

But it should be easy to apply after flying and I wasn't going to ever uncowl the whole plane after every flight to seal up the breather holes etc.  You seem to have done the remaining homework for the rest of us Mooney flyers.

Edited June 18, 2019 by pwnel

[tmo]

On 6/18/2019 at 4:31 PM, jetdriven said:

I put a thin piece of Nashua aluminum contractors tape over that hole. But before I did I put thumb prints all over the bottom half of the tape so that’s the part that goes over the hole so it doesn’t obstruct all but it does shielded by a lot

OK, I am ignorant, so I don't get this.  The tape you mention is basically duct tape, right?  Can you please explain the thumbprint / does not obstruct part?

[carusoam]

@tmo

Sounds like Byron has created a ‘flapper valve’ using duct tape...

he gave references to a specific brand name of tape...

And using his thumb (dirt/oil) to destroy the adhesive properties of the piece of tape...

Done properly, the valve allows air to escape, and inhibits air to flow back in...

Just a guess on my part...

Best regards,

-a-

[tmo]

Makes sense, thank you.  Just to confirm, can it be left in place, or does it need to be removed before flight?

[carusoam]

that duct tape would be difficult to remove each flight...

Seeing if @jetdriven is around...   ^^^^

-a-

[pwnel]

On 11/29/2019 at 4:21 PM, carusoam said:

that duct tape would be difficult to remove each flight...

Seeing if @jetdriven is around...   ^^^^

-a-

I ended up getting the BlackMax and simply had them make me longer hoses.  With the bottom cowl off, I measured how deep I need to insert the hose to go past the hole and marked it.  Now I just stick it up there up to the marker after every flight.  

[tmo]

@pwnel - do you recall / can you please measure how long it ended up being?

[Austintatious]

On 6/14/2019 at 1:34 PM, Bryan said:

I have a TCM engine, but still the same concerns.  Just about every flight that I return to my hanger, I open the oil cap and let the crankcase breathe out the steam while I push-back and clean the plane up. I do not do this when remote. I am unsure it does anything but it cannot hurt as long as I cover it back up before leaving for the day.  I also acquiredan "Engine Saver" on the cheap that de-humidifies the engine thru the breather tube.  I have used it and it seems to do what it was designed to do: pump low humid air into the engine to "dry" the engine from normal condensation generated from combustion.  Again... I figure it cannot hurt.

I have been noticing that if i leave my cap on, the next time I open it I am greeted to green slime (oil-water mix) in the cap and in the oil tube.  I have started loosening the cap and leaving it half off and this solved the problem... So YES it does help!

[pwnel]

2 hours ago, tmo said:

@pwnel - do you recall / can you please measure how long it ended up being?

I'll have to measure next time I'm at the hangar - it's about a foot.  In conversation with the guy from Black Max it's definitely preferred to stick it up the breather and the unit is tuned with regards to the pressure it produces to be used like that.  I've seen a big reduction in iron in my last oil analysis.  My next step is to be more scientific and to modify an old oil cap to lower a humidity sensor into the engine after use and compare humidity with and without the Black Max.  

Edited December 4, 2019 by pwnel

[tmo]

Sweet.  Keep me posted, me likey a project, especially if I can follow someone smarter.

[Austintatious]

On 6/17/2019 at 11:06 AM, jetdriven said:

We bought a Tanis engine dehydrator and then put orange and white beads in it because the blue ones are toxic. Cobalt.

Then I modified it with the humidity sensor and switch. Because the stock configuration it runs all the time and depletes the beads quickly.

Are you sure about that?

From the instructions 

When the Engine Saver is first turned on, it is designed to run continuously for 1 hr. This will flush all of the moist gas out of the crankcase as the engine cools, and establish a protective shield of dry air inside the crankcase and the cylinders. After the initial hour has passed, the systemgoes into the monitoring mode

[jetdriven]

I’m pretty sure that’s not the instructions for the Tanis engine dehydrator.

[pwnel]

On 12/4/2019 at 12:09 PM, tmo said:

Sweet.  Keep me posted, me likey a project, especially if I can follow someone smarter.

Realized I never answered you.  It's 12" - the tape is my mark for stopping when I shove it up the breather and it was marked visually with the cowls off to make sure the stopper goes past the hole.

 

 

 

[tmo]

As I take the lower cowl off, @pwnel posts the measurements perfect timing - thank you for making me smile, I needed it!

[Vno]

Here is my attempt at a portable engine dehumidifer. Altered the plans from the Baker .pdf. Works pretty well but I would prefer a more powerful air pump. Seems to run about 18 hours before it loses its charge. The solar aspect does allow it to recharge and run again. Total cost was around $110.00. I have had high metal counts in my oil that lowered after I added this and flew the aircraft more. So it didn't hurt it. I just recharged the desiccant (about two hours). It lasted more than a month running full time outside in the New England humidity.

Brian