Makeshift engine heater?

hiflier said:
"I don't see how a UL approved heater certified to use in a house is a fire hazard located in an area where there are exhaust pipes heated with 1500* exhaust. If you ran ductwork from a heater to the front of the cowl, you could keep it 18" above the floor just like a water heater in a garage.
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Bingo. UL approved household heaters are not required to be intrinsically safe and can make sparks, because they are approved for use in a house, not in a garage / hangar environment with a potential for gasoline fumes if there is a leak.
 
hiflier said:
"If it is cold enough outside and the lid gets cool, I can make it rain off the inside of the lid, regardless of the outside air dewpoint. "

I've had it rain in my hangar and even inside my airplane. Now I always leave a door open on the plane and the oil cap off the engine. I use a small ceramic heater that operates at 900w which sits on the muffler with a blanket over the cowel set to start 3 or 4 hours before etd. I don't see how a UL approved heater certified to use in a house is a fire hazard located in an area where there are exhaust pipes heated with 1500* exhaust. If you ran ductwork from a heater to the front of the cowl, you could keep it 18" above the floor just like a water heater in a garage.
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no matter what time of year, holt or cold, pre-heating or not, if it's a lycoming crack open the dipstick when you leave. You're going to check it again before you fly anyway. You'll be amazed how much water you'll let escape through the dipstick tube even though there's a breather. It may or may not make a difference on camshaft rust, but it can't hurt.
 
ElPaso Pilot said:
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Man, not even a capacitor across those points....

"Where's the Kaboom?. The aludium Q36 Space modulator has been stolen!"
 
JHW said:
A friend of mine lost his twin cessna to a fire from the guy next door heating his mooney's engine with shop lights. If you want a heater, get a heater. As for condensation, I know a little about that having formerly managed an engine cold test facility. All heaters are bad for your engine if you leave them on and worse if you let them cycle on-off.
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I've read this before. Where can I find some consolidated data to present to the other owners of my aircraft? As they say, 'documentation beats conversation'.

JHW said:
no matter what time of year, holt or cold, pre-heating or not, if it's a lycoming crack open the dipstick when you leave. You're going to check it again before you fly anyway. You'll be amazed how much water you'll let escape through the dipstick tube even though there's a breather. It may or may not make a difference on camshaft rust, but it can't hurt.
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This makes sense enough to me, but I'm still wet behind the ears...I'm sure if I were to repeat it I may get funny looks. But I'll give it a try post-flight and see if I see anything (steam) coming out of the oil tube.
 
" UL approved household heaters are not required to be intrinsically safe and can make sparks, because they are approved for use in a house, not in a garage / hangar environment with a potential for gasoline fumes if there is a leak. "

I'm not so sure about all of this. The UBC classifies a hangar as a B-3 occupancy and prohibits devices generating a glow or flame capable of igniting gasoline vapor within 18 inches of the floor in any room in which Class 1 flammable liquids are used or stored. Your lease or some fire regulation that I don't know about may address portable electric heaters, but I don't see where they are any more capable of sparking than an electric drill or something like that.
 
Jaybird180 said:
I've read this before. Where can I find some consolidated data to present to the other owners of my aircraft? As they say, 'documentation beats conversation'.
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1st person observation beats any of the above, so do your own test. Use the dipstick as a proxy for the camshaft. With the dipstick in tight, turn on the heater in cold weather. Next day take the dipstick out, it will be warm and dry. Re-tighten dipstick and turn off heater. Check again next day. Your camshaft is coated with the same tiny water droplets you'll see on the dipstick.

Every time you heat you create water vapor, every time you cool you condense it out. The best bet is to not pre-heat until you are ready to fly, but if your plans change after you have turned on the heater, leave the heater on until you do fly whether that is a week or a month. You should never see a heater hooked to a timer.
 
JHW said:
1st person observation beats any of the above, so do your own test. Use the dipstick as a proxy for the camshaft. With the dipstick in tight, turn on the heater in cold weather. Next day take the dipstick out, it will be warm and dry. Re-tighten dipstick and turn off heater. Check again next day. Your camshaft is coated with the same tiny water droplets you'll see on the dipstick.

Every time you heat you create water vapor, every time you cool you condense it out. The best bet is to not pre-heat until you are ready to fly, but if your plans change after you have turned on the heater, leave the heater on until you do fly whether that is a week or a month. You should never see a heater hooked to a timer.
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How can you create water by heating? Do 2 moles of Hydrogen bind to a Mole of Oxygen from the oil? Sorry for the sarcasm, but I feel that there's some step I'm missing in the discussion.
 
Jaybird180 said:
How can you create water by heating? Do 2 moles of Hydrogen bind to a Mole of Oxygen from the oil? Sorry for the sarcasm, but I feel that there's some step I'm missing in the discussion.
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You burn fuel in the engine. It produces water vapor and carbon dioxide (plus some extra pollutants due to additives and incomplete burning). Some of this makes its way into the oil. Probably a lot more than you might think.
 
So, why not just let the water settle to the bottom of the oil pan until the next run?

FWIW- I pull the prop through 2-3 times before starting when it's <40F. We have an electric engine heater installed under the cowl (not sure what brand). I've often thought it was bad to leave it plugged in between flights (which can be several days or weeks).
 
Jaybird180 said:
How can you create water by heating? Do 2 moles of Hydrogen bind to a Mole of Oxygen from the oil? Sorry for the sarcasm, but I feel that there's some step I'm missing in the discussion.
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"Since gasoline is about 87% carbon and 13% hydrogen by weight, the Hydrogen in a gallon of gasoline weighs 0.8 pounds (6.3 lbs. x .13). We can then multiply the weight of the Hydrogen (0.8 pounds) by 9, which equals 7 pounds of H2O or water and water vapor."


A good amount of this 7 pounds of water/gallon of gas does not go out the tailpipe, but passes the piston rings and valve stem seals as blow-by into the crankcase. Some of this ends up in the oil pan during operation, and more condenses out of the crankcase volume when the engine cools down after shutdown.

When you warm up the oil, you bring this back out again.
 
Jaybird180 said:
So, why not just let the water settle to the bottom of the oil pan until the next run?
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Sounds great.

Until you heat it up and force it back out of the oil pan due to vapor pressure.

Why do you heat it up? You are trying to reduce the oil viscosity so it doesn't act like molasses.

Now where does the water vapor go?

And what happens if you don't fly and let the engine cool back down again?
 
ElPaso Pilot said:
"Since gasoline is about 87% carbon and 13% hydrogen by weight, the Hydrogen in a gallon of gasoline weighs 0.8 pounds (6.3 lbs. x .13). We can then multiply the weight of the Hydrogen (0.8 pounds) by 9, which equals 7 pounds of H2O or water and water vapor."


A good amount of this 7 pounds of water/gallon of gas does not go out the tailpipe, but passes the piston rings and valve stem seals as blow-by into the crankcase. Some of this ends up in the oil pan during operation, and more condenses out of the crankcase volume when the engine cools down after shutdown.

When you warm up the oil, you bring this back out again.
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After reading all this ,

I better clarify why I run heat ALL the time without condensation issues.... My motor has two breathers, the left valve cover is a filter for the incoming air to ventilate the crankcase when to motor is running, When it is not running the condensation vents out of it as it is the highest point of the motor. The right side valve cover has a port that leads to a crackcase evacuation system that uses vacuum created by the exhaust. That vent goes downhill and CANNOT vent out condensation as warm air /moisture rises. That is the problem with aircraft motors,, all their vents are at the top of the motor and go downward inside a tube to vent under the cowling and out the bottom of the aircraft. If that vent was able to discharge at the highest point then there would be little if any moisture trapped in your crankcases...
 

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Burned exhaust from a gasoline engine contains a bit less than 15% water by weight (180mg/L at nominal temperature / pressure).

Blow-by volume varies from about .5% to 5% of the total intake flow and is a mix of unburned and burned fuel / air mixture. Your crankcase is filled with blow-by gasses. What's in the blow by? Crankcase concentration data from an engine with a PCV system at various operating conditions:
CO2 0 – 3%
NOx 0 – 60 ppm
H2O 10 -90 mg/L
O2 14-19%
The PCV system dilutes the crank case gasses (that's where the zero numbers come from) but aircraft engines don't have positive ventilation and will have at least the highest levels of H2O, CO2, etc.listed. Blow-by also contains sulfate and nitrate ions which can turn into sulfuric and nitric acids in the crank case. Not a good thing.

Blow-by also includes a lot of unburned fuel which can dilute your oil.

At room temperature, air can hold about 17mg/L of water - if your crankcase is at 90mg/L it's just plain gonna condense when the engine cools down. Each time, every time. There is lots of water inside your crankcase. Period.

The water and acids cause corrosion. And, the higher the temperature, the faster it corrodes. The only thing that keeps your engine from collapsing in a pile of rust in a couple years is that everything tends to be covered with oil...

So, what do you do?

Running the engine long enough to get the oil hot will help drive out any excess water that has been accumulating from previous operation – that's the standard recommendation. Engines that run only short times and don't warm up are just going to build up more and more and more and more water and icky stuff. But even a good and hot engine will have plenty of condensation after shut down.

Running heaters isn't going to make the water go away over any short term period - you only have a little diameter tube connected to the outside and no flow - and the breather tube is long enough that diffusion is going to be a very slow process. Taking the oil filler cap off when the engine is hot will let some of the hot air (which will be saturated with water) out and reduce the total amount of water in the engine (more so on a wet sump engine).

If you want to be a hero and make the world a better place (at least as far as engine durability is concerned) come up with a crankcase vent system that flows fresh air through the engine and get an STC. You won't get much ventilation during flight - you don't have the manifold vacuum available. But during the descent / landing / taxi a PCV system should blow the crankcase out reasonably well. Failing that, for a wet sump engine, you could stick an aquarium pump in the dip stick tube (or breather tube with the dip stick loose) and let it push fresh air through the engine while it is shut down – the water and fuel adsorbed in the oil will eventually evaporate. For a dry sump engine, you would have to figure out an inlet / outlet path for the air that may or may not involve the dipstick.

Note: corrosion rates typically double with every 20F rise in temperature (google it yourself if you don't believe me - it's not that hard). You want the engine to either be cold or running and splashing oil around.
 
I've seen the moisture when removing the oil filler cap on my warm automobile engine. Makes sense.
 
Now that we've discussed getting energy into the engine, let's move on to how we keep it from escaping. I find I get much better results from the "dora and boots" child's bed comforter on this side than with the "Buzz Lightyear" blanket on the other side. I can only speculate that since Buzz was designed to operate in the vacuum of space, his blanket is not optimized for convection in air.
 

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The darker inks used to make Dora and Boots absorbes more of the UV light spectrum.
 
ElPaso Pilot said:
"Since gasoline is about 87% carbon and 13% hydrogen by weight, the Hydrogen in a gallon of gasoline weighs 0.8 pounds (6.3 lbs. x .13). We can then multiply the weight of the Hydrogen (0.8 pounds) by 9, which equals 7 pounds of H2O or water and water vapor."


[snip]
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7 lbs. of water from 6 lbs. of gasoline (plus oxygen, I realize)? I'm to lazy right now to look up my HS Chem where we worked out those kind of equations, but intuitively, I think that's way, way high.

John
 
I just hook a vacuum pump to my engine and pull it down to 500 microns. Not enough moisture or oxygen left to cause corrosion. If it would hold a vacuum this would sure do it.
 
...or your could intentionally flood the engine in an oil bath and all the water suspended would go to the bottom of the oil pan. Then when it's time to fly, you could pump it all out back to the normal level. Pump it from the bottom and never worry about renewing the oil again. Just change the filter every 50hrs.
 
Jaybird180 said:
...or your could intentionally flood the engine in an oil bath and all the water suspended would go to the bottom of the oil pan. Then when it's time to fly, you could pump it all out back to the normal level. Pump it from the bottom and never worry about renewing the oil again. Just change the filter every 50hrs.
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well, I do store my spare O-540 parts along with some lycoming cylinders and a bunch of tractor parts in a stock tank full of diesel and used oil
 
From an HVAC tech perspective, if you can find an old air handler with electric heat, and have a portable generator that handles 240volt. You could use flex duct up to the aircraft, and just run a basic thermostat into the engine compartment, wire the air handler with a plug. Voila! Over sized portable pre heater.
 
jsstevens said:
7 lbs. of water from 6 lbs. of gasoline (plus oxygen, I realize)? I'm to lazy right now to look up my HS Chem where we worked out those kind of equations, but intuitively, I think that's way, way high.

John
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Apparently, too lazy to review the math in the post you responded to as well.

The bulk of the weight of water comes from the oxygen. It's a really, really bad approximation to ignore it.
 
Jaybird180 said:
...or your could intentionally flood the engine in an oil bath and all the water suspended would go to the bottom of the oil pan. Then when it's time to fly, you could pump it all out back to the normal level. Pump it from the bottom and never worry about renewing the oil again. Just change the filter every 50hrs.
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As a hint as to why this isn't going to work at all, try changing your own oil in your car after letting it sit overnight. See how much water comes out separate from the oil.

It's not true that oil and water don't mix. They mix into an emulsion. You're not going to get any separation.
 
MAKG1 said:
Apparently, too lazy to review the math in the post you responded to as well.

The bulk of the weight of water comes from the oxygen. It's a really, really bad approximation to ignore it.
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No, I reviewed the math in your post. I just suspect it's not correct. I'll try to find time to do the other calculations over the weekend when I find my reference book and if I'm wrong I'll post it. If I'm right I'll post that as well. I know you can't ignore the oxygen.

And, for the record, I'm not being snarky.
John
 
jsstevens said:
No, I reviewed the math in your post. I just suspect it's not correct.
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Not my post. ElPasoPilot's.

He's right. Your engine consumes roughly 15 times as much air by weight as it does fuel. About 1/5 of that air is oxygen. You have a missing factor of 4 in your "suspicion." You're getting 7 lb of water from 24 lb of reactants.
 
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MAKG1 said:
Not my post. ElPasoPilot's.

He's right. Your engine consumes roughly 15 times as much air by weight as it does water. About 1/5 of that air is oxygen. You have a missing factor of 4 in your "suspicion." You're getting 7 lb of water from 24 lb of reactants.
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Sorry about misattributing the post. Yep. I see the additional reactant. It just seems intuitively wrong. Which is why I'd go find the reference and do the more detailed reaction math with products of combustion, etc. But I'm at work not where my reference materials are. And it's been mumblety years since high school chem where I did such math. Hopefully I can do it this weekend and I'll post the results - whether they agree with me or not.

John
 
If we assume gasoline to be in the ball park of C8H18 (IsoOctane) then

2C8H18 + 25O2 = 16CO2 + 18H2O

Hydrogen has an atomiic weight of 1, Carbon is 6, Oxygen 8

So 2C8H18 = 132
18H2O = 162.
 
The products you buy all the gimmicks you try, there is no substitute for a heated hangar.
 
Sure that's only for people who make love to an inanimate object.

(says the guy who used to park a bike in the living room)
 
hiflier said:
"If it is cold enough outside and the lid gets cool, I can make it rain off the inside of the lid, regardless of the outside air dewpoint. "

I've had it rain in my hangar and even inside my airplane. Now I always leave a door open on the plane and the oil cap off the engine. I use a small ceramic heater that operates at 900w which sits on the muffler with a blanket over the cowel set to start 3 or 4 hours before etd. I don't see how a UL approved heater certified to use in a house is a fire hazard located in an area where there are exhaust pipes heated with 1500* exhaust. If you ran ductwork from a heater to the front of the cowl, you could keep it 18" above the floor just like a water heater in a garage.
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Elevating the heater 18" is probably sufficient and that does meet the NEC requirement for garages but they also consider anything within 5ft horizontally to be Class I hazardous (no sparks) from the floor up to 5ft above the airplane.

There are three fire hazard issues to consider, fuel vapors collecting near the ground, flammable liquids dripping onto hot surfaces, and heater malfunction/overheat. How one addresses this in one's own hangar is pretty much a personal choice thing and I think a little common sense along with an awareness of the potential hazards can eliminate the significant risks of any heating means.
 
You can always count on the NEC to spoil the fun. NEC is, however, like the law. Lots of exceptions and interpretations. It would appear that in addition to heaters not approved for class 1, division 2 areas, you can't use electrical tools or anything else within 5 feet. And, no battery trickle charging either.
 
hiflier said:
You can always count on the NEC to spoil the fun. NEC is, however, like the law. Lots of exceptions and interpretations. It would appear that in addition to heaters not approved for class 1, division 2 areas, you can't use electrical tools or anything else within 5 feet. And, no battery trickle charging either.
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Waitaminute. Within 5 feet of what exactly? Does this mean that the battery minders aren't legal?

FWIW, there are dual batteries in the tail of the airplane, with two cigarette lighter plugs on the hat shelf in the baggage compartment that the battery minders plug into. The battery minders themselves sit on top of a shelf a few feet behind the trailing edge of the right wing in the hangar and about 4.5 feet off the floor.
 
From the floor to five feet above and five feet horizontally from the wings and the engine. No battery charging in that area.
 
JHW said:
OTOH there is the real world
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Yep, there is the real world, where btteries are maintained IAW their ICAs.

The re-charging of batteries must done as directed by the manufacturers instructions or your aircraft is not airworthy.

I don't make this Sh-- up, It is written by the manufacturers so they can sell more product.
 
Here's my engine pre-heater. In the time it takes me to pre-flight it raises all temps (CHT & OIL) at least 25dF above ambient. I didn't buy anything...I just made it from stuff laying around one of my jobsites.

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I would never leave it running unattended nor would I fuel the airplane while pre-heating. It works well but one must understand the limitations.
 

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Tom-D said:
Yep, there is the real world, where btteries are maintained IAW their ICAs.

The re-charging of batteries must done as directed by the manufacturers instructions or your aircraft is not airworthy.

I don't make this Sh-- up, It is written by the manufacturers so they can sell more product.
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I've never seen ICA's that specify location of the batteries and battery charger with respect to where the airplane is parked
 
JHW said:
I've never seen ICA's that specify location of the batteries and battery charger with respect to where the airplane is parked
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Yer right, because the batteries are required to be removed from the aircraft.
 
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