Makeshift engine heater?

You need to be careful with adding duct work to those heaters. I have a similar torpedo heater I use occasionally in my detached garage. The instruction manual specifically prohibits adding ductwork to either the inlet or outlet of the heater. The fan isn't designed for it. The squirrel cage fan in my Red Dragon heater is much more powerful than the blade fan in the torpedo heater.

timwinters said:
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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David said:
You need to be careful with adding duct work to those heaters.
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Very true, that's why the duct I used is bigger than the torpedo itself, is relatively short, and why it's not attached but rather an air gap remains.

I would not advocate physically attaching ductwork to a torpedo as I've seen many do.
 
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JHW said:
you potentially restrict airflow leading to poor combustion and excessive carbon monoxide production
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And... Excessive heat at the discharge end of the ductwork... Adding an airgap will introduce additional air so the temp comes down , but the CFM goes way up.. That will preheat faster then high heat /low flow. IMHO.
 
Jaybird180 said:
What happens when they do?
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It really depends on the unit, and how the exhaust air is being discharged.
If the duct area is smaller, or you have turns, this will increase friction, and pressure. The internal fan may burn out. If the temp limit safety failed, that could be a problem. Also possible to cause incomplete combustion, which emits high levels of Carbon Monoxide(CO) and soot(just what every aircraft engine needs, mine as well fly through some volcanic ash). If you use the same size duct, and it is just really long with shallow corners, the air is going to cool and lose velocity. More likely to have a warm duct, with cool air at a low velocity coming out. Also, if you use duct work over exhaust vent, you may have some really hot metal that may burn something, or someone, if hot enough set something on fire.
 
Jaybird180 said:
What happens when they do?
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I will predict that the engineer who designed the device will call you the equivalent of an aviation test pilot.

It wasn't likely designed or tested in that configuration, and bad things regarding temperature, combustion, product life, and/or "unintended thermal events" are all in the realm of possibility.
 
Well... I'd talked to my aunt about this a while ago, before I started thinking about other (cheaper) options. Talked to her again about it more recently, and she said "Oh, don't worry about it. Your uncle would have put it on if he'd moved it to Wisconsin."

Done. Full Reiff system (oil sump heater and cylinder bands) on the way. The days of $42.24 preheats will soon be over!

I already bought a nice pair of cowl plugs for it, and I'll probably be using an old comforter to help keep the heat in too, though my experience with Reiffs is that the cowl plugs will keep plenty of heat in (we have Reiff preheaters on the 182 and DA40, and I'll stick my hands in the oil door to warm them up during preflight on a cold day).
 
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Good call.

Kent, it seems to me that your uncle would have wanted *you* to have the Mooney... :D
 
SCCutler said:
Good call.

Kent, it seems to me that your uncle would have wanted *you* to have the Mooney... :D
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Agreed. I think Kent ought to be searching for a partner rather than a purchaser.
 
Problem with that is that I'm on the East Coast and I don't think he will be patient enough to agree to a 100 year amortization schedule:D
 
gismo said:
Agreed. I think Kent ought to be searching for a partner rather than a purchaser.
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Oh, I've talked to a few local folks about that... But for me to afford it, it'd have to be about a 5-way partnership, and that's a lot of people to corral. I guess I should put a listing on the AOPA partnership site.
 
Love the Tanis on my aircraft. I've got it on a timer so it comes on automatically on the weekends, that way I don't have to drive out to the hangar to plug it in. I would rather have one of those cell phone activator thingies, but my electronic mojo isn't quite up to it.
 
flyingcheesehead said:
Oh, I've talked to a few local folks about that... But for me to afford it, it'd have to be about a 5-way partnership, and that's a lot of people to corral. I guess I should put a listing on the AOPA partnership site.
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I think AdamB has a 4 or 5-way on the Trinidad, and seems to be happy with it. For most people, that's probably a good number to keep the use up.

steingar said:
Love the Tanis on my aircraft. I've got it on a timer so it comes on automatically on the weekends, that way I don't have to drive out to the hangar to plug it in. I would rather have one of those cell phone activator thingies, but my electronic mojo isn't quite up to it.
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FWIW, that's really not a great way to operate it since that will increase condensation and internal corrosion. It's that kind of operation of engine pre-heaters that made the theory come about that pre-heating causes corrosion. You're actually better off leaving the pre-heater on all the time if you don't want to go by the airport to plug it in before a flight.

Alternately, if you disagree with me and don't think it matters, then have fun. :)
 
Ted DuPuis said:
FWIW, that's really not a great way to operate it since that will increase condensation and internal corrosion. It's that kind of operation of engine pre-heaters that made the theory come about that pre-heating causes corrosion. You're actually better off leaving the pre-heater on all the time if you don't want to go by the airport to plug it in before a flight.
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What Ted said.

I've also heard that having only the oil sump pad can have the same effect, as it doesn't keep the entire engine warm - Water vaporizes out of the oil and then condenses in the cold top end.

Ted (and anyone else who cares to answer, I suppose ;)), what do you think about unscrewing the dipstick for additional ventilation? Good idea? (I would think so, but alas, I don't know it all any more. :rofl:)
 
flyingcheesehead said:
What Ted said.

I've also heard that having only the oil sump pad can have the same effect, as it doesn't keep the entire engine warm - Water vaporizes out of the oil and then condenses in the cold top end.

Ted (and anyone else who cares to answer, I suppose ;)), what do you think about unscrewing the dipstick for additional ventilation? Good idea? (I would think so, but alas, I don't know it all any more. :rofl:)
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There is a post on Beech Talk from Lew Gage (vintage Bo guru) where he mentions hooking up a vac to suck out the hot, moist air post flight. Are you a member over there? If so, I can go dig it up.
 
I've never pulled out the dipstick for ventilation, but I don't see why it would hurt things any.

Removing the hot air post-flight is definitely a good idea. That air also has lots of moisture in it, and is very humid. We're going to buy some engine dehydrators to use on the 310 with the new engines.

Now, how much does any of this really matter? Well, as with everything else, it depends. There's the ideal right way to do things (Tanis heater, engine blankets, dehydrator, fly regularly), the wrong way (cycling your pre-heater with no blanket and no dehydrator, fly rarely), and then there's everything in between. None of them guarantee a reliable or unreliable engine. The previous owner of the 310 had his pre-heater (a 100W lightbulb) on a timer with army blankets, no dehydrator, but flew the plane regularly. The engines made it 17 years and 2100 hours with no corrosion issues.

Meanwhile, a Mooney Missile owner (IO-550) had his Tanis on a timer, fancy engine cover, and flew semi-regularly, but had corrosion within a couple hundred hours. Maybe it's the oil used (that matters), maybe he was just unlucky. Maybe I should start a thread on how to make your engine last to be a Maintenance Bay sticky.
 
jhausch said:
There is a post on Beech Talk from Lew Gage (vintage Bo guru) where he mentions hooking up a vac to suck out the hot, moist air post flight. Are you a member over there? If so, I can go dig it up.
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I like the guys who use a little aquarium air pump hooked up to a dessicator to blow clean dry air in through the oil filler round the clock.

That makes sure the engine gets dry.

One shot with a vacuum would help, but I would still think that there will be a lot of water left inside.

Need to cobble one of those dessicators together someday.
 
Ted DuPuis said:
FWIW, that's really not a great way to operate it since that will increase condensation and internal corrosion. It's that kind of operation of engine pre-heaters that made the theory come about that pre-heating causes corrosion. You're actually better off leaving the pre-heater on all the time if you don't want to go by the airport to plug it in before a flight.

Alternately, if you disagree with me and don't think it matters, then have fun. :)
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Don't disagree, but way better than not flying the airplane or starting it in the cold. I don't live very near my airport, so driving to the hangar to plug it in is a significant barrier. I fly a lot more now that I don't have to plug in a couple space heaters and wait for a half hour for it to warm up. Airplane now flies more weekends than it doesn't. And it'll get hurt a lot more if I ball it up due to a lack of currency than it ever will getting warmed on the weekends.

Often, there just isn't a perfect solution.
 
steingar said:
Often, there just isn't a perfect solution.
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Correct. I was just making the point that it's not ideal.

Often times, we choose to operate in a manner we know isn't ideal for the purposes of compromise on goals. Sounds like that's what you're doing.
 
ElPaso Pilot said:
I like the guys who use a little aquarium air pump hooked up to a dessicator to blow clean dry air in through the oil filler round the clock.

That makes sure the engine gets dry.

One shot with a vacuum would help, but I would still think that there will be a lot of water left inside.

Need to cobble one of those dessicators together someday.
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That's pretty much what the units you can buy will do. Some recirculate, but I think the fresh air is probably better. Makes sure you flush all the corrosive gasses out, too.
 
I have had numerous discussions with my A&P and several other A&P folks that have really discouraged me from the Tannis/Reif route. I use a torpedo heater and a duct arrangement to divert the air into the nose gear opening. Yesterday it took about 20 minutes to get the engine warm to the touch and it was 24 in the hanger. I work in the HVAC industry so knew I didn't want a direct connection as it would be way to hot and would mess with the heater. I have read all the comments regarding the NEC and hangers and to be honest I never even thought about that as I always preheat with at least two of the 6 door sections open, and never leave the hanger while heating is in progress. I am sure it isn't up to the NEC but my mechanics tell me I have a good setup. But then Opinions are like A$$ Wholes, everyone has one and the usually stink, including mine on any given day.
 

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tmyers said:
I have had numerous discussions with my A&P and several other A&P folks that have really discouraged me from the Tannis/Reif route. I use a torpedo heater and a duct arrangement to divert the air into the nose gear opening. Yesterday it took about 20 minutes to get the engine warm to the touch and it was 24 in the hanger. I work in the HVAC industry so knew I didn't want a direct connection as it would be way to hot and would mess with the heater. I have read all the comments regarding the NEC and hangers and to be honest I never even thought about that as I always preheat with at least two of the 6 door sections open, and never leave the hanger while heating is in progress. I am sure it isn't up to the NEC but my mechanics tell me I have a good setup. But then Opinions are like A$$ Wholes, everyone has one and the usually stink, including mine on any given day.
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I like your setup there.

Curious, on what basis have your mechanics discouraged the use of the integrated heaters (Tanis, Reiff)? I love my Tanis, I plug it in, the oil and cylinders get warm, the engine starts up like it was a comfy spring day, oil circulation is normal, all is wonderful with the world.
 
The Torpedo heaters are really not that great. Get the cylinders warm, yes, but not the crank and bearings. It's like when you take a casserole from the freezer and put it in a hot convection oven. The outside gets warm quickly, then you put your fork in it and it's frozen in the middle.

Torpedo heaters are what lead to a spun bearing and failed engine one cold winter's night on the 310 with its previous owner. That wasn't a nice feeling for him.

Most A&Ps that discourage Tanis heaters do so because of the results of improper use, just like those who discourage LOP operation.
 
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I am sure there worries come from those that use the thermostat cubes and turn the heaters on and off. The flying club I was in (same field) had a policy that the airplanes were plugged in anytime it was expected to drop below 50 degrees. Of course with 30+ people sharing 2 airplanes they flew about 250 to 300 hours a year. I was actually ready to purchase either a Tannis or Reif and have it installed this past fall at annual but on their recommendations did not do so. Had not thought about your casserole analogy. Maybe I will spring for it this winter since flying will be a bit slower.
 
I'm thinking I'm going the 100w bulb route myself for the Apache -- no cowl flaps on her (Augmenter tubes). Where would you guys recommend I put the bulbs for optimal use?
 
Apache123 said:
I'm thinking I'm going the 100w bulb route myself for the Apache -- no cowl flaps on her (Augmenter tubes). Where would you guys recommend I put the bulbs for optimal use?
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Florida. That'll ensure that your engines are warm enough when you go to start 'em. ;)

FWIW, I got the Reiff Standard system - 100W on the oil, 50W per cylinder for a total of 400W. I plan to leave it plugged in all the time in the hangar, with cowl plugs and an engine blanket. 400 watts total plus some insulation should keep it nice and toasty warm.
 
Ted DuPuis said:
I've never pulled out the dipstick for ventilation, but I don't see why it would hurt things any.
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It'd certainly allow a path for air to pass through the breather and the dipstick tube and get moisture out faster.

However, I'm wondering whether it'll just put moisture on the outside of the engine instead... I'll have at least the cowl plugs in to help keep the heat in. Since the plug is going to be under the oil door, I was also planning on putting a blanket over the cowl. So, there won't be much in the way of air circulation under the cowl... And won't the moist air rise to the top? (If it sank, that'd be great - It'd sink right out the cooling outlets.) Hopefully the relative volume of gas inside the engine vs. inside the cowl and the slightly better ventilation combined with the warmth inside the cowl from the heater will keep things reasonably dry. :dunno:

Removing the hot air post-flight is definitely a good idea. That air also has lots of moisture in it, and is very humid.
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Hmm. That is a good idea... Unfortunately, I don't have a spare vacuum to donate to the cause.

Now, how much does any of this really matter? Well, as with everything else, it depends.
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I've often wondered how long you could make engines last with a heater, a dehydrator, and a pre-oiler. (And maybe a little Marvel Mystery Oil. ;) :rofl:)

Maybe I should start a thread on how to make your engine last to be a Maintenance Bay sticky.
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Please do!
 
timwinters said:
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.

attachment.php


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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damn fine design Son, damn fine design!

I used to keep my reiff heater on all the time but the mechanic said not to so I left it unplugged but called the airport on days I intended to fly and they would plug it in for me. I never flew super early but if I did, I'd have them plug it in night before.

Of course I had the protection of Marvel Mystery Oil. :)
 
flyingcheesehead said:
What Ted said.

I've also heard that having only the oil sump pad can have the same effect, as it doesn't keep the entire engine warm - Water vaporizes out of the oil and then condenses in the cold top end.

Ted (and anyone else who cares to answer, I suppose ;)), what do you think about unscrewing the dipstick for additional ventilation? Good idea? (I would think so, but alas, I don't know it all any more. :rofl:)
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no need if you are only plugging it in few hours before the flight. But this brings up another type of heater, Seems to me I have seen oil dip stick heaters that just go down the dip stick to heat the oil. Again 1 or 2 hrs before a flight.
 
Tony_Scarpelli said:
over kill. plug this into oil dip stick end. $7.99

http://www.harborfreight.com/inline-desiccant-dryerfilter-68215.html

You will know when it quits it turns pink.
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It's not very clear how long it'll last, though. One of the reviews states that you'd need three for a simple home painting project. I don't want to run to the hangar every day to switch one out, plus this is only a filter, not an air pump.

I wonder how long you'd need to pump a hair dryer through the oil dipstick hole to exchange the air in the engine... That'd get you 80% of the way there.
 
flyingcheesehead said:
It'd certainly allow a path for air to pass through the breather and the dipstick tube and get moisture out faster.

However, I'm wondering whether it'll just put moisture on the outside of the engine instead... I'll have at least the cowl plugs in to help keep the heat in. Since the plug is going to be under the oil door, I was also planning on putting a blanket over the cowl. So, there won't be much in the way of air circulation under the cowl... And won't the moist air rise to the top? (If it sank, that'd be great - It'd sink right out the cooling outlets.) Hopefully the relative volume of gas inside the engine vs. inside the cowl and the slightly better ventilation combined with the warmth inside the cowl from the heater will keep things reasonably dry. :dunno:
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I'd figure it's one of those things that just doesn't matter much. If you look at the dehydrators, they will either plug into the breather and then pump air out of the oil filler, or plug into the oil filler and pump oil out of the breather. I think I like plugging into the oil filler and pumping out the breather, since that's then pushing air and whatever internal corrosive gasses, etc. overboard rather than under the cowlings.

Hmm. That is a good idea... Unfortunately, I don't have a spare vacuum to donate to the cause.
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The engine dehydrators will do this for you.

I've often wondered how long you could make engines last with a heater, a dehydrator, and a pre-oiler. (And maybe a little Marvel Mystery Oil. ;) :rofl:)
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It depends on what kills them. Preheating will save the cold-star wear. Dehydrator will save corrosion. Pre-oiler would theoretically save wear prior to oil reaching the components.

Something else would probably kill it first. ;)

Please do!
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Ok, I'll write it when I get a chance here. Make sure to request it to get stickied. ;)
 
Tony_Scarpelli said:
But this brings up another type of heater, Seems to me I have seen oil dip stick heaters that just go down the dip stick to heat the oil. Again 1 or 2 hrs before a flight.
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I might put a dipstick heater in a $500 airport car that's parked off in a corner away from any hangars, but not in a $30,000 aircraft engine.

They have to dump a lot of energy through very little surface area to do any good, they get hot, and can degrade the oil.

Numerous reports of coked up, burnt oil on the heaters, as well as stores that won't sell them due to engine fires.
 
steingar said:
Don't disagree, but way better than not flying the airplane
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no, it isn't. Temperature cycling is the worst thing you can do, far worse than leaving the engine cold and inactive.
 
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