Is an engine dehumidifier needed and recommendation?

Based on the corrosion problems seen with cams and the occasional inactivity by the pilots of those aircraft, are engine dehumidifiers recommended and commonly used nowadays? I have not seen comments on other forums that are very conclusive about the topic so I a hoping there are some good points of view here.

I have seen some reviewed like the Black Max (newer version of Engine Saver) and the EICU. The Black Max looks good from the perspective that it does not use a desiccant so there would not be a need for recharging it on a regular basis.

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

http://www.enginedryingsystem.com/

Dr. Randy has the setup....

I have now been running the EICU for a couple of years. Felt like it couldn’t hurt here in humid Virginia. Well my last oil sample, Blackstone’s first word was wow! What have you done to improve all of my results! EICU- my oil sample results mirror what the inventors sample results he has posted on his website.

NDRII said:

I have now been running the EICU for a couple of years. Felt like it couldn’t hurt here in humid Virginia. Well my last oil sample, Blackstone’s first word was wow! What have you done to improve all of my results! EICU- my oil sample results mirror what the inventors sample results he has posted on his website.

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How long does the EICU unit last before the desiccant needs to be recharged? I know that varies by humidity, but what would be a good average timeframe? How do you recharge the desiccant? Do you put it in the oven?

When it’s all connected and sealed up, I go 6 months between recharging.

I purchased a second batch of the desiccant, and keep it handy in an airtight container. When it needs recharging, pour it into a lage tinfoil turkey pan, 3 hours at 275 in the oven and done!

Virginia is certainly not the most humid spot, but it is humid.

Norm

I suspect that the humidity where the airplane lives and perhaps the amount of idle time, or rather the length of idle periods will have an effect on the "need" for one of these units.

In any case, I doubt they can hurt anything.....and they might just save you some money. Problem is, how will you know if it works?

MTV

I just built my own out of an airtight container, aquarium pump, desiccant and tubing... I tried to buy the EICU that NDRIII recommends but I could not get them to respond to any inquiries.. I'll post some pics of the one I built.

About a year ago I looked around at a few commercially available engine desiccating units. I wound up building 2 of my own design.
After a bit of refining I am very happy with the project and think it was worth my time and also worth the ongoing effort to keep up with connecting to the plane after each flight and drying out the silica gel when it becomes saturated.
I used a recirculating design which I think is essential to reduce rapid saturation of the beads due to ambient air exposure. I circulate into the oil filler neck and out the crankcase breather. One super interesting thing we note every time we attach the desiccator after a flight is the instantaneous moisture condensation which develops on the inside of the clear tubing coming out of the breather tube. Very evident the inside of the engine is full of moisture. I bought a small humidity meter with a probe and once the set up is stabilized, I remove the crankcase tube and measure humidity of the air being pumped out of the engine. If the beads are fresh, it is always at 10-11%. If the beads are saturated then the humidity of this air is ambient. In the summer I allow this and figure the original combustion generated moisture from the prior flight is gone, which should still be a benefit. In the winter I put a nitrile glove over the exhaust but don't know if it impacts moisture levels inside the engine. Evacuated air stays dry either way if the beads are dry.

ChrisM said:

About a year ago I looked around at a few commercially available engine desiccating units. I wound up building 2 of my own design.
After a bit of refining I am very happy with the project and think it was worth my time and also worth the ongoing effort to keep up with connecting to the plane after each flight and drying out the silica gel when it becomes saturated.
I used a recirculating design which I think is essential to reduce rapid saturation of the beads due to ambient air exposure. I circulate into the oil filler neck and out the crankcase breather. One super interesting thing we note every time we attach the desiccator after a flight is the instantaneous moisture condensation which develops on the inside of the clear tubing coming out of the breather tube. Very evident the inside of the engine is full of moisture. I bought a small humidity meter with a probe and once the set up is stabilized, I remove the crankcase tube and measure humidity of the air being pumped out of the engine. If the beads are fresh, it is always at 10-11%. If the beads are saturated then the humidity of this air is ambient. In the summer I allow this and figure the original combustion generated moisture from the prior flight is gone, which should still be a benefit. In the winter I put a nitrile glove over the exhaust but don't know if it impacts moisture levels inside the engine. Evacuated air stays dry either way if the beads are dry.

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How did you configure the recirculator? Mine pumps ambient air into silica beads to dry it then up through the breather tube... I would like to recirculate like the EICU design. The air humidity going into my engine through the breather is at 16%... But I am not in a humid climate...

I was only meaning that I set it up as a closed loop. It is not designed to be open to ambient air.
The pump is a Tetra Min aquarium device which is modified to pull from a tube buried in the desscant (half gallon mason jar). Then it pushes the same air now dried, back into the oil filler neck, thru the engine, out the crankcase vent tube, thru the dessicant, into a buried airstone and back to the pump.

NDRII said:

I have now been running the EICU for a couple of years. Felt like it couldn’t hurt here in humid Virginia. Well my last oil sample, Blackstone’s first word was wow! What have you done to improve all of my results! EICU- my oil sample results mirror what the inventors sample results he has posted on his website.

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What changed in the report? Percent of water in the oil sample? What we’re the levels of water in previous reports? Thanks, Jim

Some good threads on this website on this subject found via Google search "engine dehumidifier site:supercub.org"

https://www.supercub.org/forum/showthread.php?41542-Winter-chills-and-moisture-in-the-crankcase

https://www.supercub.org/forum/showthread.php?56335-Avoid-rust-in-the-engine-how

cruiser said:

What changed in the report? Percent of water in the oil sample? What we’re the levels of water in previous reports? Thanks, Jim

Click to expand...

I would post my last test, but the magic of gmail playing on iOS, once the email is in the trash, it will not download the attachment.

The link at the bottom here, is years of data from the maker, my last test have resulted in the same.

I don’t know that this will ever make a difference. I know from the built in hygrometer the air measured at the “out” side of engine starts at ~50% after a flight then quickly settles in and is maintained at 5-10% constantly.

Finally, no there hasn’t been any significant change in the water in the oil. The significant change has been metal concentrations in the oil sample. See these results:

https://www.enginedryingsystem.com/?page_id=59

Norm

I built my own, actually built four. This one was made out of a box I welded up. The other three used metal ammo boxes. Each end of the box has a small electronics cooling fan mounted in it, one blowing in and the other blowing out. Both are powered by an old left over power supply. You can buy a desiccant container that is perforated and has a clear window in the screw on top. That just sits in the box. I milled the cone shaped ends out of Delrin. They mount over the holes the fans are mounted to. One tube has a Delrin milled fitting that fits over and clamps to the oil breather line. The other tube has a fitting that slides into the dip stick tube. Two holes cut into the top of the box with plexiglass bonded to the inside. One to view the desiccant, not required since the need to replace is obvious. The other window has a small open ended box welded to the underside. That holds a magnetic temperature and humidity sensor.

Works well. When connected after a flight the humidistat jumps up significantly. It takes about 15 minutes to decrease to whatever level the desiccant is capable of at that point. Initially I left it on all the time but concluded that wasn’t necessary. Now I turn it on after a flight while I’m cleaning the bugs off the plane then put it on a timer that runs for a couple hours late in the evening and again in the morning. I change out the desiccant when the humidistat won’t go below about 45%. New or recharged beads will pull it down to around 10 to 12%.

Mr. Ed

There seems to be a lot of knowledge about the silca bead desiccant based dehumidifiers. Has anyone experience with an electrical dehumidifier like the Black Max one offered by Aircraft Components Inc.?

Black Max and Engine Saver (Black Max=more $):
http://www.flyingsafer.com/experimental-engine-saving.html

Also, on the website for the Black Max there is a link to a great article by The Twin Cessna Flyer about engine heating and humidity that looks very informative on the topic. There are lots of nice graphs of heating vs humidity. They also compare condition of lifters they bake (to dry) and then put in different combinations of oil, Camguard, and with or without dehumidifiers.

http://nebula.wsimg.com/1fd3c69cbb2...3181A996A1861998A&disposition=0&alloworigin=1

Dehydrator <$50.00

https://share.icloud.com/photos/00kb1BMMbhNQ1pE77xYl8I7cQ
You can make your own for $50.00.
10’ 1.5” ABS TUBING, 4 end caps, 4 brass nipples, tubing, aquarium pump, desiccant 5# from Michaels. (Filter for tubing, if not using coils of extra tubing).
In the oil vent tube, out dipstick tube, why? Heat rises.
I do not “recirculate”, dry desiccant out in oven q11-12months) in MN.
Why? Burned and unburned fuel, water vapor from combustion, volatile corrosive acids from combustion, burned and unburned fuel.
My oil looks as clean at 25 hours as at 0 hours.
Especially in the winter, you can observe water vapor exiting correlated tubing on oil dipstick tube, and then later observe more condensation in exit tubing.