Best Way to Preheat Engine

[IFLYIFR]

I keep my M20J in an insulated hangar. The hangar is not, however, heated. Outside temperatures have often been below zero (-12 to -5) this month; the temperature in my hangar has usually been between 30 and 35 this month (it was 26 today inside). There is no cell phone coverage at my hangar for a remote on/off power switch.

 

My question is what is the best way to use my Reiff engine heater. Option 1 - leave the engine heater plugged in continuously every day/night, even on days when I’m not flying. Option 2 - drive 30 minutes each way to the airport the day before to plug the heater in overnight (not convenient but doable). Option 3 - connect the heater to a timer that turns on every morning for 5 or 6 hours then turns off (more convenient but the engine would be heated then re-cooled every day). Option 4 - something else.

 

Thanks

 

 

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[exM20K]

Is there someone at the FBO to whom you can throw a bone to plug it in for you several hours ahead of flying?

If they have access to the hangar, great.  If they don't, you can leave two ends of extension cords connected to the wall and the plane outside the door for them to plug in or make a more weatherproof switch solution that penetrates the door.

always on or on from 9-5 are not usually a good idea.  If unable to engage a human being, I'd do the drive.

-dan

 

[Ragsf15e]

There’s always a great argument over leave it on vs only turn it on to fly.  It really seems either way is ok.  I wouldn’t want it to cycle on a timer though- either heat it and keep it warm or don’t.  So, seriously no cell coverage?  Because that’s really the easiest option.

[Marauder]

I keep my M20J in an insulated hangar. The hangar is not, however, heated. Outside temperatures have often been below zero (-12 to -5) this month; the temperature in my hangar has usually been between 30 and 35 this month (it was 26 today inside). There is no cell phone coverage at my hangar for a remote on/off power switch.
 
My question is what is the best way to use my Reiff engine heater. Option 1 - leave the engine heater plugged in continuously every day/night, even on days when I’m not flying. Option 2 - drive 30 minutes each way to the airport the day before to plug the heater in overnight (not convenient but doable). Option 3 - connect the heater to a timer that turns on every morning for 5 or 6 hours then turns off (more convenient but the engine would be heated then re-cooled every day). Option 4 - something else.
 
Thanks
 
 
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Is there WiFi available at your hangar? If so, you could use a WiFi switch like this:


Or if you know you’ll fly on certain days during the upcoming week, program this one for the week.




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[PeteMc]

I think I'd shy away from a daily timer turning on for a while and then turning off.  I think there would be a issue with moisture and the engine heats and cools, probably worse then if the engine was at ambient temperature all the time.  How many Amps does your heater pull, I'd just leave it on during the cold months if you have no way to turn it on the evening before you're going to fly.

For being able to turn it On the night before...  How many hangars near you?  Maybe you can find a number of other people that are willing to share the cost of an Internet connection.  Have it installed in your hangar or in the office if the hangar has one and then (preferably) run lines to each hangar of the people paying for the service.  I'd stay away from WiFi if possible unless everyone chips in.  Otherwise you'll find yourself paying for the Internet and other's just passing on the WiFi PW.

[Tahir K]

1 hour ago, PeteMc said:

I think there would be a issue with moisture

Any chance you or anyone can explain what you mean by moisture? I also have a heater in my plane and have been told to be careful about moisture but I don't know exactly what that means.

1. In what situation would moisture develop from turning a heater on or leaving it plugged in at all times? 

2. Where would moisture develop and how would it effect the airplane? 

3. What are ways to avoid moisture developing in said areas? 

 

Thanks! 

[larrynimmo]

What I do is differ t than others….

I have bought a 200 watt heater/blower manufactured by enginheaters…it is solid state and explosion proof.  I insert it in the pilot side cowling opening #2 cylinder…then I cover the entire cowling with a very well insulated blanket.

it self regulates to 70 degrees which keeps engine warm without overheating 

with the fact that heat rises, the upper part of the engine stays the warmest and most likely the oil would be the coolest…any formation of condensation should be on the oil…and such minor moisture would be “steamed” off when the engine is running

[HIghpockets]

I use a SwitcheOn attached to a Tanis heater. With this continued cold weather in PA I keep it on all the time. Controlled by my smartphone. I have no COI.

For more information see below:

https://www.gallagheraviationllc.com/switcheon.html <-- Order SwitcheOn here
1-833-425-5288 <-- Call me for questions
gallagheraviationllc@gmail.com <-- Email me with your questions

:
 

[PeteMc]

7 hours ago, Tahir K said:

Any chance you or anyone can explain what you mean by moisture?

As I understand it, with the heater left on (assuming it is the type that can be), then all is good.  But if you heat, allow to cool, heat, allow to cool, etc.  Then the moist air gets pulled back into the engine.  And the cycle of heating and cooling may not get all the moisture out since it takes a while for the "always on" type heaters to actually warm the engine.  I'll defer to any mechanics or others in the know on this, but that's how it was explained to me.

I'm assuming the same would be true for the cabin.  And in both cases, I'm not sure what the advantage is for heating and then allowing to cool. 

Other big issue about heating the cabin is that apparently some people use their propane engine heater to warm up the cabin.  That's not a good idea because of all the moisture in propane heat.  It's not an issue for the engine where the outsides of the engine are fine in the rain, etc.  And as the engine warms it's not going to suck in any of the moist air.  But if you just dump a lot of moisture into the cabin, especially if you're trying to warm up the front where the pilot is, then you can be dumping a lot of moisture up under the dash where all your expensive electronics are.

Again, no expert.  But this is what I've read or been told over the years.

 

[KB4]

Option #4–This 

https://switchboxcontrol.com/the-switch-box

[A64Pilot]

If you look, I believe both Continental and Lycoming warn against leaving pre-heat on, but Tanis says you can.

My take is IF the entire engine is heated then your fine, but for instance only heating the oil pan may drive moisture out of the oil and up into the cold part of the engine where it will condense (your cam) for instance.

I believe cycling it on and off could be very bad, pretty much ensuring condensation.

I’d leave it off if I couldn’t get a switch to work and plug it in when needed, and go eat breakfast or something and go back and fly.

Just my opinions

[steingar]

I'd put in the cowl plugs, cover the nose with blankets and leave it on all the time.  I have a little heater that I put in the nose, and my airplane is always ready to go.

[N9656G]

I have been leaving mine on 24/7 for the past few months on my m20J. The airplane flies every few days mainly on an XC type of flight. So far I have come to the conclusion that it is 100% beficial to leave on. I have the CYL and oil pan heaters. This allows the entire engine compartment under the blanket to stay between 130-160F no matter how cold it has been getting outside. This is what REIFF founder reccomended when I called him as well as overhaul shop that did my motor + the legenday MIKE BUSH. This debate however is a tale as old as time and you will get various answers...

Airplanes in AZ sit in the hot try sun and engines run forever. All my heater does is create a hot dry day underneeth 24/7. This to me (since I do not pay for power) is 100% logical as a way to prevent moisture from forming. 

[Rick Junkin]

On 1/30/2022 at 7:40 PM, IFLYIFR said:

Option 3 - connect the heater to a timer that turns on every morning for 5 or 6 hours then turns off (more convenient but the engine would be heated then re-cooled every day).

Here's an Option 3+. Add an Engine Saver to the mix to keep the relative humidity inside the engine low enough to prevent condensation. It's my personal year round over-kill solution, especially when I know I won't be flying for a few weeks. I hook it up and leave it on all of the time, and dry the desiccant every few weeks or so. If you defeat internal condensation then the heater cycling with a timer becomes executable and practical if you don't want to leave it on all of the time. It's a compromise solution for your unique situation. An engine dehydrator is also recommended for 24/7 preheating by Mike Busch in the last two paragraphs of this article: https://www.aopa.org/news-and-media/all-news/2019/april/pilot/savvy-maintenance-crimes-and-misdemeanors

Here's a link to the Engine Saver at Aircraft Spruce: https://www.aircraftspruce.com/catalog/eppages/engsaver.php

And here's an Aviation Consumer article discussing the effectiveness of engine dehydrators: https://www.aviationconsumer.com/maintenance/engine-dehydrators-engine-saver-prevails/

That link may be a subscriber-only link for Aviation Consumer, so let me know if you can't get to it and I'll get it to you another way.

Cheers,
Rick

Edited February 1, 2022 by Junkman
Added Mike Busch article link.

[jaylw314]

There's always the old standby of putting a 100W bulb in the cowl and blankets on top.  Of course, now you can't get 100W bulbs, I think the biggest ones are 75W or something now.

[FlyingScot]

I know this doesn't answer the original question, but...

I have a Reiff which I use when I need to heat the engine from cold in a few hours, but normally on shutdown I:

1.] open the Oil dipstick, and let the steam out (5-10 min, while I'm backing it into the hangar and battling the ice on the ramp)

2.] insert a twin hornet (these things are great) in the left (pilot) side cowl opening and position it on top of the front cylinder

3.] Lock it in place with Bruce cowl plugs,

4. ] Wrap the cowling with a Bruce Engine Blanket

5.] Attach a Black Max Dehumidifier (https://flyingsafer.com/2065) to the oil breather.

Overkill? Perhaps, but because I put the Twin Hornet in right after shutdown (it's rated for this, but the way), it never lets the engine cool down completely and cold soak - it simply cools to ~60-70 degrees and holds there, just like it does on a nice spring day ;).

I have an uninsulated hangar, and the internal hangar temp this time of year regularly gets down into the single digits. The oil and CHT temps, however never get below 60. They usually are closer to 70. I love this combo, because it is a set-up and forget, and whenever I need to go the plane is ready - 

No timer, switch or other stuff needed...

 

[larryb]

Warm air holds more moisture (water molecules) in suspension than cold air. Water in vapor form is not available for corrosion. So I am in the camp of keeping the engine warm all the time to minimize corrosion.

 

How warm do you say? A few years ago I built a temperature and humidity measuring device that sent data in real-time via a cellular radio back to my server so I could monitor it. I found a temperature of 90 degrees F would keep the humidity to the < 30% RH range, which should keep things corrosion free. Another function of the same device is a PID temperature controller which uses PWM to cycle the Reiff heater every 10 seconds to maintain a perfectly stable temperature. This whole thing is a custom device I designed and built, but a handy hangar elf could use this from Amazon to achieve a similar result in controlling the temperature:

 

https://www.amazon.com/Inkbird-Temperature-Controller-Voltage-Thermocouple/dp/B08Y8GX1WT/ref=sr_1_1_sspa?keywords=pid+temperature+controller&qid=1643752666&sprefix=pid+temper%2Caps%2C128&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUE2QklBWE1QMDlJVkomZW5jcnlwdGVkSWQ9QTA1MDIyODMxNEJMU0xaUDJINFI3JmVuY3J5cHRlZEFkSWQ9QTAwNDczNDMyQllRSEYwUUxKWElHJndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

 

Here is the current graph. Landed yesterday afternoon, this shows about 24 hours after the flight. Current humidity around 27%. 

[A64Pilot]

On 2/1/2022 at 3:08 PM, jaylw314 said:

There's always the old standby of putting a 100W bulb in the cowl and blankets on top.  Of course, now you can't get 100W bulbs, I think the biggest ones are 75W or something now.

You know I was thinking about that myself, 75W is more heat than you think. Many of us have used a drop light in a boats engine compt. It keeps the ole Diesel warm and dry too, used a drop light as they are pretty well protected and are available without custom anything. 

They use a special rough duty bulb that doesn’t blow nearly as easily as a regular bulb if you drop it.

Amazon has them and clams they are shatterproof, a broken bulb could of course be a source of ignition.

https://www.amazon.com/Satco-Shatterproof-Safety-Coated-Service/dp/B009O8WN54/ref=sr_1_6?crid=OREX15QNZ5XF&keywords=drop+light+bulb&qid=1643919168&sprefix=drop+light+bulb%2Caps%2C145&sr=8-6

 

Edited February 3, 2022 by A64Pilot

[carusoam]

On 1/31/2022 at 1:02 AM, Tahir K said:

Any chance you or anyone can explain what you mean by moisture? I also have a heater in my plane and have been told to be careful about moisture but I don't know exactly what that means.

1. In what situation would moisture develop from turning a heater on or leaving it plugged in at all times? 

2. Where would moisture develop and how would it effect the airplane? 

3. What are ways to avoid moisture developing in said areas? 

 

Thanks! 

Let’s see…

We covered…

heating…

Drying…

Avoiding wet air…

 

The only thing we didn’t cover is where all that moisture comes from, and how it gets inside the engine…

 

Believe…

All that gasoline you put in the tanks…. Secretly carries gallons of water in it…!  Literally gallons that the fuel pump eagerly delivers, under cover….

No… not the milligrams of moisture that can dissolve in the gas… this is more sinister….   

 

We always discuss the CO2, CO, and sometimes NOx…. Coming out of the exhaust 

But we never discuss the gallons of water that come out of the chemical reaction of gas + air = water and CO2 plus a lot of heat… (and those other things above)

 

yeah… that water… lots of it sneaks past the rings and mostly escapes out the case vent….

Nobody cares for this lonely water…. That has been dying for attention…. 

 

Every time we start the engine… the water starts showing up…. A few molecules at a time…

Expect every time you turn the engine off… steam can be seen escaping from the oil cap when you open it…

If left closed… the oil cap has a tendency to collect water droplets on the inside… aka condensation.

That is a sign that each time the engine is run… the hot air inside the engine has 100% RH in it….  As it cools, the excess moisture falls out of solution on the cooled surfaces inside….  Leaving the 100% RH solution of air, of the lower temperature environment…

Let the moisture out…

Use a dryer…

always keep the parts covered in oil…

fly the plane weekly if able…

Lots of different ways to keep the air in the engine at a lower RH… or keep it slathered in oil….

 

How was that?

-a-

[81X]

Since you’ve already considered a cell based on/off which would fit your need, why not try to fix the cell coverage issue with a cell signal booster & antenna?  
 

something like this:

https://www.amazon.com/Verizon-Signal-Booster-Amplifier-Extender/dp/B09MH53D35/ref=zg_bs_2407782011_10/136-0273690-8253658?pd_rd_i=B09NDXFDM1&psc=1

[Ragsf15e]

My personal technique has been to turn on my preheat the night before I fly in the winter.  I have an sms power switch that i use to turn on a small ceramic heater.  Set on low with a dryer duct up into the cowl flaps, it works well.

Today though, I saw something hard to believe.  Last week we were in the 20s for highs, and dry.  30s last weekend and still dry.  Yesterday, an atmospheric river hit us and it was really moist and ~55.  Today I went to my hangar.  It’s insulated and weatherstripped but hardly airtight.  You can see daylight through several places.  Concrete floor.  Metal all the way around, in the middle of a long row.  The hangar floor and the airplane were straight up wet.  Like water dripping off.  It was shocking how much water.  Even the tired were soaked all the way around.  I can only imagine it was real cold and then that moist warm air hit it and condensed.  Makes me wonder what happens inside the engine??  I was happy to fly it today and get it all dried out!

[IFLYIFR]

Thanks everyone for your very thoughtful suggestions and help. I bought the SwitcheOn plus the remote antenna about three weeks ago. I attached the remote antenna to the metal hangar wall as high as I can reach INSIDE the hangar. Although the signal strength isn’t great, it is good enough to reliably work.

I also bought a ~$25 handheld IR thermometer to measure the cylinder temperatures before unplugging the Reiff heater.

The outside temperature has been between 0 and 10 degrees nearly every morning in January and February and usually below 20 during the day. My hangar is insulated with inside temperature usually about 30 degrees on these types of days.

I use the SwitcheOn to turn the heater on from home and the cylinder temperature usually reach 50 to 55 degrees within 3 hours.

I really like the display on the SwitcheOn device. It displays signal strength, UTC time, local time, and temperature.

It would be great if SwitcheOn added humidity to the display.


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[carusoam]

Nice pirep for the switcheon ifly!

Thanks for sharing it…

Best regards,

-a-

[lotsofgadgets]

Or you could take a more radical solution like I did and move to Florida ;-)

 

But seriously, I simply used a WiFI remote switch to turn the Tanis on.  Though if you read the studies Tanis has done, they recommend leaving the heater plugged in as it will keep the engine internals above the dew point, but not so hot as to force water out of the oil.  

 

[A64Pilot]

Just curious, you guys that live in the great white North, are you running straight weight oil?