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Old 01-01-2021, 02:34 PM
A2022 A2022 is offline
Join Date: Apr 2011
Posts: 2,425

Originally Posted by HAL Pilot View Post
How large of a desiccant bottle does it take? If a metal one was attached to an exhaust pipe it would cook dry on every flight.
it probably would not take much but in the interest of total performance, do you really want to carry around a dense drying agent that would probably get turned to dust with vibration from an exhaust? I am thinking a total weight of less than .25 lb. some folks could justify that weight but probably not much more.
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Old 01-01-2021, 04:58 PM
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BillL BillL is offline
Join Date: Sep 2007
Location: Central IL
Posts: 7,008
Default On board is a great idea!!!

. . . Even if it is powered by shore power.

The Black Max uses a Peltier device. I tested one (peltier device, not Black Max) and it produced a 21F dew point, pretty dang good for room temperature. Note the Max has a defrost and condensate clear cycle.

My calculations indicate that 2.5 l/ min will replace the crankcase air in 30 min. A separate battery with a timer could do this.

The question not answered yet is whether there is any liquid in the crankcase that might evaporate and recharge the crankcase air. In spite of a handful of tests, the humidity meter readings are not consistent - - meaning I can not make sense of them.

I currently use a 12VDC mattress inflator to purge the engine for 5 min the pump in desiccated air for 60 min. It was getting complicated to manage a peltier device with a control so went back to the silica gel. The purge and timer process eliminated the need for closed loop and the desiccant last a long time (between regenerations) this way.

Last edited by BillL : 03-16-2023 at 09:04 AM.
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Old 01-01-2021, 05:17 PM
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BillL BillL is offline
Join Date: Sep 2007
Location: Central IL
Posts: 7,008
Default Crude test of Peltier

Here is a page from my development workbook.

-Dew Point relative to ambient temps is what is important.
-There is 2.5X more water in the crankcase than running a dryer for 2 hours at high ambient humidity
-A peliter device must have some way to defrost and purge condensate or it will plug.

Many Peltier devices look alike - be sure you get a good one. This one was inspected with a borescope and the internal passages were too restrictive even for 2 liters/hr flow.

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Last edited by BillL : 01-01-2021 at 05:24 PM.
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Old 01-01-2021, 05:29 PM
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MacCool MacCool is offline
Join Date: Aug 2020
Location: central Minnesota
Posts: 1,606

I made one for about $50. The expensive part was the dessicant, I bought 15lbs and rotate. When the one half turns orange, I switch for the other half blue stuff and take the orange stuff back home to turn it blue again in the oven. 7.5 lbs goes for about a month, maybe 6 weeks. The aquarium pump was cheap. After I put the plane back in the hangar, I just stopper the outflow air tube in the dipstick tube, and the return tube slip overs the Anti-Splat separator (crankcase vent) outflow. Takes about 90 seconds and avoids having yet one more thing mounted under the cowl.
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Old 08-25-2022, 01:45 PM
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johnbright johnbright is offline
Join Date: Aug 2010
Location: Newport News, Va
Posts: 514
Default 2065 quick and gratis repair

Quick and gratis repair so excellent service from Aircraft Components Inc.

My Black Max 2065 failed after 2-1/2 years of continuous use. Fellow on the phone said temperature sensor failed as is common, they normally expect a four year life of that part.

Cost me $21 to ship it on Aug 17, delivered Aug 20, repaired Aug 25, will ship back to me Aug 26.
John Bright, RV-6A, N1921R, at FWF
O-360, 8.5:1, vert sump, dual SDS EFI EM-5-F
Z101 as a template, links
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Old 03-16-2023, 08:55 AM
rockwoodrv9 rockwoodrv9 is offline
Join Date: Dec 2011
Location: Meridian ID, Aspen CO, Okemos MI
Posts: 3,348
Default Black Max engine dehydrator

With all the talk lately I have been hearing about corrosion I figured I should learn more about it. Im in a humid in Michigan area but try to fly at east once a week.

My oil temp never gets high enough to boil out all the moisture so I compensate by changing oil around 20 -25 hours. So far all reports from Blackstone have come back fine.

I always pre-heat my engine and with my AntiSplat oil plug heater and a 5" dox heater ducted into my plenum inlet, I can get the oil and carb to 90 + in about 3 hours starting at 10 degrees F.

I open the dipstick after landing. Im not sure if that is good or makes things worse.

My questions:
1. Should I leave the dipstick open?
2. Should I plug up the exhaust pipes and close the dipstick?
3. I prefer a solution that I just hook up after a flight and forget about it until I fly again without having to replace pellets. Is the Black Max engine dehydrator the easiest and a good solution?

There is an EAA webinar by Mike Bush saying 40% or less humidity is the goal. I am leaning to the Black Max. Any other suggestions that do not require replacing the silica pellets? Thanks
Williamston MI
O-320 D2A
Flying N376E
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Old 03-16-2023, 10:36 AM
thinkn9a thinkn9a is offline
Join Date: Nov 2007
Location: Mississippi
Posts: 337
Default few comments

- somewhere in the info on the dehydrator is a comment that it is designed for a “tight” engine,…. So, LEAVING the dipstick open is not a good idea

- I have been using the dehydrator for several years and have found on occasion that it got locked up in reset cycle. I put it on a timer to operate for 3 hours or so,… then a break for 1-2 hours then operate, and no longer have an issue

- after flying I open the dipstick immediately after shutdown, to allow natural ventilation ( and heat) to purge. There is not an air/oil separator installed. I also use a inflator pump at times
Wallace & Marietta Goodloe
9A -QB
Phase 2 has started!
Thanksgiving time, is dues time for us
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