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Engine Dehydrator

stewartb

MEMBER
I see them in the catalogs and don't know what to think. I built a couple to test. It's what I like to do. Turned them on at 3:00 today. I'm looking forward to seeing if they reduce the relative humidity inside the engines.
 

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Funny, headline got my attention, I was also experimenting with a dehydrator today.
Sliced up a bunch of persimmons to squirrel away for winter.
great results so far.
maybe convert your setup to fruit drying if experiment fails ?

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Stewart, make sure your hose goes up past the siphon break hole in your breather or at least cover the hole somehow or else you will not achieve best results.

Kurt
 
I remembered to cover the whistle hole, thanks.

Using a cheap digital hygrometer The current relative humidity in the hangar is 33%. After 11-1/2 hours with my dehydrator running the crankcase RH is 15%. Yesterday hangar and crankcase were equal. I didn't know what to expect but I'm pleasantly surprised. Now to see how long the beads stay blue.
 
Sterwartb

See this:

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

I have had the system for 4 years here in humid Virginia. System turns on at 10% off at 5%. Mine holds 48 ounces of desiccant, last 5-6 months in the winter and 2-3 months in the humid months. Bought a second batch of desiccant so once it goes pink, dump the spare in and take it home to recharge. My oil results are similar, matter of fact Blackstone said Wow! On my report.

I don’t know if it will make a difference, I think it’s worth the try.

Norm
 
Is that a blow pump or. Suction pump?


Sent from my iPhone using SuperCub.Org

Mike if your question is in reference to the one I posted. It is a closed loop. A fan mounted in its case sucks from the dip stick tube into its sampling “chamber” then pumps the air back into the crankcase breather and the exhaust pipe.
 
Mine is a $10 aquarium pump, a 6# (one gallon) jar of desiccant, and a few through-bulkhead plastic fittings, all from Amazon Prime. Cost about $60 per airplane.
 
Just out of curiosity, why wouldn't you just run desiccant plugs? Seems like a lot of extra things going on with the pump and all that
 
for above the piston rings there cool, this is for below and every where else it looks like. but hope it dosent draw outside air humidty??
 
Just out of curiosity, why wouldn't you just run desiccant plugs? Seems like a lot of extra things going on with the pump and all that
Plugs only protect inside the cylinders, leaving the Cam to fend for itself. Besides changing plugs in and out between flights would not be fun.
 
And now hangar RH is 35%, crankcase is 10%. Crank case dew point 3.3° F. Absolute humidity 1.33 grams per cubic meter. Pretty damn dry by any standard. Interesting.
 
Mine is a $10 aquarium pump, a 6# (one gallon) jar of desiccant, and a few through-bulkhead plastic fittings, all from Amazon Prime. Cost about $60 per airplane.

Just one way into the case with super dried ambient air? what is outlet? dipstick?
 
Have similar system only put fitting drilled into pump housing for inlet air coming from a plug in oil filler. Closed system averages 12%. Interesting during duck season when I make shorter flights (under 20 minutes) it takes an extra 10-12 hours to get to 12% and a lot of visible moisture in return hose. Oil temp usually over 185.
 
Just one way into the case with super dried ambient air? what is outlet? dipstick?

Outlet air is going out the cylinders. After seeing how fast my inert gas leaked out I don't think a vent is important. I do feel some pressure release in the new Lycoming when I open the dipstick/filler. No pressure in the Continental at the oil filler. Both are reading 10%. I need to find out if 10% is the low limit on the hygrometer.
 
Dry & Dry 6# Blue Premium Indicating Silica Gel Beads- $29.99
Rifny adjustable air pump kit with dual outlet- $15.90
Quickun 3/16" hose barb thru-bulkhead fitting 2 pack- $8.99
Quickun 5/16" hose barb thru-bulkhead fitting 2 pack- $10.99
Anpatio 19 pcs tapered solid rubber stopper plugs- $9.89
Silicone tubing-10' piece 5/16 ID- $10.99

I used one 5/16 fitting for the jar lid and one inserted into a rubber stopper to fit my breather. I made two kits so the stoppers and 5/16" hose were shared for two setups. Vinyl tubing would work, too. The aquarium pump includes plenty of 3/16 tubing for both outlets and I used the stones inside the jar so the beads can't get into the tubing.
 
Glad to see some data! I built a similar system this past spring and although it appears to be working having some proof is very comforting. I used a closed loop system where the pump sucks air from the desiccant jar and is fed to the crankcase via a dipstick cap modified with a barb fitting. I figured the engine should be pressurised so any leakage would be outwards. I used two return lines - one from the exhaust pipe and the other from the whistle slot in the breather (and the end plugged). The idea for the exhaust pipe return was that you'd dry out at least some of the cylinders above the piston (or at least more quickly). After shut-down when turned on I can feel a breeze from the whistle slot and the plastic tubing develops condensation immediately. When I first installed it you could watch the desiccant turn colour gradually radiating outwards from where the moist air entered the jar. After a couple days the distance stayed constant indicating the humidity had stabilised. Pretty neat I thought.

Cheers,

Jeff
 
I'm curious about these closed systems and how they don't lose dry air or gain moist air through the cylinders. The pressure would need to be equal to or greater than suction? Pushing air into the breather and suction from the dipstick would be easy if I had a pump with a suction input. Cheapo aquarium pumps don't.
 
I'm curious about these closed systems and how they don't lose dry air or gain moist air through the cylinders. The pressure would need to be equal to or greater than suction? Pushing air into the breather and suction from the dipstick would be easy if I had a pump with a suction input. Cheapo aquarium pumps don't.
They get their air from somewhere. Usually a opening in the case. Plug input, drill and insert fitting in housing and you have a suction port—EZ
 
Stewart if your pump is outside of the engine bay (which from the photographs it seems to be) then you will always be fighting with the current RH in the hangar, would it not be an idea to put the pump INSIDE the engine bay, plug up the engine bay air intakes and outlet, then you would create a "microclimate" within the engine bay that will mean you need to replace the silicon beads a lot less often. sure there will be leakage but the majority of the air moved through the system will already have been dried by the system. not sure how your air filter is connected (as I assume that is the natural air outlet in this case)

container with desiccant can remain outside of engine bay, its just a matter of making the tubing long enough, air pump is small enough to just sit on lower cowl push through from underneath then a shaped foam plug with a bit of duct tape closing the lower cowl outlet, then you can pop the lid off the desiccant jar and empty/exchange easily.
 
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My dehumidifying procedure: three squirts of throttle, pull six blades through, mags on, light the fire and fly the humidity right out of it!
 
but right after the fire is turned off the white snot comes on gangbusters and says thankyou for the renewed life.
 
3DA10D51-444C-4277-99A1-3BB8BE84A1C3.jpegWorks well, open system. $50.00. Open because it also removes volatile burned and unburned fuel, combustion products such as acids, etc. as well as humidity. Runs 24x7 at minimal cost for an aquarium pump. Beads last 10-12 months in Mn, before changing out with some oven dried beads.
 

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Stewart if your pump is outside of the engine bay (which from the photographs it seems to be) then you will always be fighting with the current RH in the hangar, would it not be an idea to put the pump INSIDE the engine bay, plug up the engine bay air intakes and outlet, then you would create a "microclimate" within the engine bay that will mean you need to replace the silicon beads a lot less often. sure there will be leakage but the majority of the air moved through the system will already have been dried by the system. not sure how your air filter is connected (as I assume that is the natural air outlet in this case)

container with desiccant can remain outside of engine bay, its just a matter of making the tubing long enough, air pump is small enough to just sit on lower cowl push through from underneath then a shaped foam plug with a bit of duct tape closing the lower cowl outlet, then you can pop the lid off the desiccant jar and empty/exchange easily.

Read two posts above yours. I plan to keep the current pumps running on their lowest setting now that the humidity is purged and see how long the beads last before needing to be dried. Amclosed system may last longer between drying but I want to see how this one works first.
 
I'm curious about these closed systems and how they don't lose dry air or gain moist air through the cylinders. The pressure would need to be equal to or greater than suction? Pushing air into the breather and suction from the dipstick would be easy if I had a pump with a suction input. Cheapo aquarium pumps don't.

In my case the pump had no inlet port per se but it got air via a small hole in the (sealed) plastic casing. By chance the inlet hole diameter was a tight fit on the OD of the plastic tube I used so I pressed the tube in and then routed it to the desiccant jar. I ultimately ended up mounting the pump to the jar lid so that tube is only 2" long or so.

I assume that it draws most leakage air in from the carburetor/intake via the cylinders which are not on the compression stroke, or through the gap between the breather tube and the dehydrator tube at the whistle slot. I fit a foam plug against the airfilter (square type) and in the carb heat box outlet to try and block some of the flow.

Managed to find some pictures. Here's when first installed:
20191223_123227.jpg

And after 2 weeks:
20200112_120616.jpg

It then took another 2 months before it needed a refresh.

Cheers,

Jeff
 

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I ordered a pump with an intake fitting so I can compare the free air setup to a return air system.
 

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Opinions will vary, but IMHO the main challenge to an engine will be the water and acids left in the crankcase and cylinders at the time of shutdown. I don't think that ambient humidity is such a big deal. I blow out my still-hot engine through a tube introduced through the oil fill port with dessicated air for 5 minutes after engine shutdown. I cycle the prop once about halfway through the 5 minutes. I use an air mattress pump and a homemade dessicant chamber (molecular sieves, Amazon, hardware store PVC fittings) with a couple of hardware store valves to protect the dessicant between uses.
 
I like data, and wanted to KNOW what the humidity. So I put my Dehydrator (it has no obvious intake port) into a $6 clear plastic tub and sealed it with packaging tape. My humidity measuring device sitting in the bottom shows I'm at 16%. The two hoses run through Grommets. Air goes into the case through the breather tube, and exits through the dip stick. Drilled rubber stoppers hold 1/4" AL tubing which attaches to the dehydrator. Our largest concern is not Cylinders, rather corrosion on Cam and Lifters that reside in the top of the case due to condensation of the could moist air in the case. I'm building, and this, along with dehydrator plugs is my engine storage program.
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