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Thread: Preheating engine couling

  1. #1

    Default Preheating engine couling

    I just bought my first plane, and was wondering what everyone used to warm up your engines ie heating pad, electric heater. I was thinking of wiring up an electric buddy heater with an inline thermistat and just drop it right in the couling. I have a 2000 honda suitcase generator would this be sufficient or be a hazard.

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    Congratulations, what did you buy? Preheating is a good subject as everyone has a preference. Pads and electric heaters are good when you have a place to plug in. Portable heaters are preferred when on the move or parked out say on Lake Hood. I used a red dragon type most of the time and had a gas heater to keep in the plane. I always liked to be around the plane when preheating and when using a red dragon it took about 30-40 minutes which was about the time it takes to get ready to go in the winter. Your set up will be fine but I think hauling around a generator is cumbersome unless you have a cabin. YMMV
    Pete

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    For several years I have been using a Red Dragon pre-heater. It is basically a propane powered mini Hermin Nelson type heater.

    http://www.flameengineering.com/Preheater_12voltDC.html

    I bought mine from A.I.H. and it was less expensive than buying it at an aircraft supply place.

    It has a couple cables that hook up to a 12 volt battery and I use a small propane tank from a BBQ. You can hook up the power leads to your truck, plane or a rechargeable starter battery pack gizmo.

    The air volume moving through the cowling heats the entire engine within 15 minutes. Then you can pre-heat your instrument panel and cabin interior.

    I have also used my Red Dragon to thaw water pipes and warm up my crawl space. Oh and it has heated a hanger more than once.


    For bush use, I used to use a 5 gallon metal can with air holes and a pump up camp stove. It also doubled as a tent stove...
    Floatplane,Tailwheel and Firearms Instructor- Dragonfly Aero
    Experimental Hand-Loader, NRA Life Member
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  4. #4

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    So you bought the red dragon which the lightest it is 18lbs then you need duct work and a propane bottle correct.So there is no flame near the actual plane. Also what temps are you preheating at. I live in the interior cutoff for flying will be -10 maybe -20 in emerg., but you must be out of ANC or around the coast.

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    I have a smaller version of the red dragon which I use here at the airport. I have a Northern companion type to carry with in the plane. There are many stove type heaters and many are home made and work very well. There are also catalytic(sp) heaters that will fit into the cowl to keep the engine warm although they are not real good at heating a cold engine. The most portable pre heaters use flame and stove piping, these need to be monitored at all times. The piping should also NEVER be directed on any gasoline bearing object such as carburator, fuel line or gascalator. Check some out at the airplane parts place, online or what your flying buddies are using. Go check out someone preheating their plane. Don't be bashful pilots love to talk about airplanes and what works for them. Good luck it is all fun, except being stuck in overflow.
    Pete

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    Thumbs up my thoughts

    Go to the engine manufacturers info for the official word on preheating and cold starts. That is the first step in learning the truely correct numbers and procedures. You will find that lycoming doesnt recomend needing preheat till 20f.

    I use electric pads on the engine for my planes. There are a lot of pluses to this. Why would you want to light a fire under you expensive and fragile gas can with wings???? I know it has been done for many years, but there has also been lots of planes burnt up that way too. You can carry your generator with you in the plane and it wont take up any more space an weight than a red dragon, and , you can use it for other things , like if you are camping, a light, a tent heater, etc. When I am pre heating my plane, for the last 20/ 30 minutes I put the generator in the cabin of the plane and it preheats the inside, (instruments etc). Open the door for a minute and all the fumes are gone

    You CAN NOT preheat an engine properly in 15 minutes, it takes a long time to get that heat in to the core of the engine, especially whern it is really needed (-10, -20 or more).

    Use multi grade oil also, it will make a BIG difference if you ever have to start without preheat.

    Be sure you have all the correct covers also. Winter flying can be a hassle and complicated but and also be WAY worth it!!

    Have fun, there's my $.02 worth

  7. #7
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    I live in the interior cutoff for flying will be -10 maybe -20 in emerg.,
    Here in the Homer area it seldom gets as cold as you are mentioning.
    At least at the airport. Although it sure does once you get away from Kachemak Bay.

    I usually pre-heat when it gets down to +20F or less, depending on the engine and aircraft.

    My little 90 horse Cub will heat up in 15 -20 minutes to the point that the cylinders and engine casing are hot to the touch and the engine oil temp gauge shows a reading. This is only if I use my insulated engine cover. It was 20-30 minutes with my PA-12, C-150/150hp and PA-18. With temps from 20 above to zero, it would be double that at the temps you are talking about. It is not because the air is so hot from the Red Dragon, which it is, but because of the air flow volume.

    We also use my heater for the local C.A.P. C-182. That plane's engine takes 35-40 minutes or longer. The engine cover for that plane is non-insulated. Then we do the interior and instruments for a few minutes.
    The Red Dragons have an electric blower so the air volume is a nice thing. The hot exhaust from the propane flame does not make my C02 detector go nuts.

    The CAP C182 has an electric oil pan heater that we leave on all night before a mission flight. It helps, but the engine still feels cold to the touch.
    So we still preheat the engine with my Red Dragon blower.

    (We have a heated hanger this year, which is super cool.)



    I have the small red dragon on which we replaced the electrical (jumper) cables and I put of a longer propane hose. My buddies and I have used it more than once to de-ice entire (Metal) aircraft. The most recent being one we had to leave up in Ninilchik for a couple of days. Plus I have several lengths of flexible metal tubing..

    The extra hose and cables let us get up on ladders and melt ice out of some interesting places.

    Jay, one of our other local CAP guys takes his Red Dragon in his C-172, but he hauls along a small propane bottle.

    I use Phillips synthetic oil in my plane and the CAP dictates the use of Exxon Elite in their C-182. Synthetic oil REALLY helps.

    Be aware of trying to do a cold start when you should really be pre-heating.

    A 18 years ago I set my PA-12 on fire when trying to save time.

    My son and I had camped out at a ice fishing hole up west of Willow. It was around zero... It was getting dark again so I tried to fire up the engine before it was properly warmed.
    It sorta started and I had to keep pumping the throttle to keep it turning over. Well it quit again and did that fire-fire and back-spin deal that they love to do when cold and flooded. It was a Lic 0-290-D2.
    The back-spin and back-fire set the flooded carb on fire and then the gas that had leaked into the cowling. I noticed when the light from the fire began to show through the firewall (down by my feet.) as the fire burned away the caulking around the cable and fuel lines.
    We set a world record for filling the engine compartment with snow.

    That was a very expensive lesson.
    Floatplane,Tailwheel and Firearms Instructor- Dragonfly Aero
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    Default Grizzly 1

    Quote Originally Posted by saltwatertom View Post
    Go to the engine manufacturers info for the official word on preheating and cold starts. That is the first step in learning the truely correct numbers and procedures. You will find that lycoming doesnt recomend needing preheat till 20f.

    I use electric pads on the engine for my planes. There are a lot of pluses to this. Why would you want to light a fire under you expensive and fragile gas can with wings???? I know it has been done for many years, but there has also been lots of planes burnt up that way too. You can carry your generator with you in the plane and it wont take up any more space an weight than a red dragon, and , you can use it for other things , like if you are camping, a light, a tent heater, etc. When I am pre heating my plane, for the last 20/ 30 minutes I put the generator in the cabin of the plane and it preheats the inside, (instruments etc). Open the door for a minute and all the fumes are gone

    You CAN NOT preheat an engine properly in 15 minutes, it takes a long time to get that heat in to the core of the engine, especially whern it is really needed (-10, -20 or more).

    Use multi grade oil also, it will make a BIG difference if you ever have to start without preheat.

    Be sure you have all the correct covers also. Winter flying can be a hassle and complicated but and also be WAY worth it!!

    Have fun, there's my $.02 worth
    I have to agree with SALTWATERTOM about flames under the cowling. My answer, for all my airplanes, was (1) an 800-watt engine (car engine) heater inside the cowling and (2) another under an interior seat. With an outside electrical connection faired in, the plalnes could be plugged in overnight. Worked to -50. Both heaters were permanently installed.

    For out-in-the-bush heating, I'm afraid I gave way to weight considerations. Used a one-burner Coleman (like a plumber's pot) and a length of 5 1/2" diameter flexible hose. This was placed at an angle over the burner, with the other end just inserted behind the cowling. Never had a fire, but wouldn't let the thing stand unattended, either. Be sure to give the heating enough time to thaw the oil deep into the center, since there's nothing worse than finding a frozen ball of oil there when you're already in the air!

    Mort

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    To the original post? You don't need to preheat your engine cowling. You need to preheat your engine. Mostly your engine oil. Cold oil will leave the oil pressure needle on zero far longer than I'm comfortable with. A little cylinder heat is nice to keep from frosting the plugs but by the time your oil is adequately warmed the cylinders have received some of that heat.

    Red Dragons are the worst product ever invented for aircraft preheat. I've used one. I've watched dozens and dozens of other guys use them, too. Not once have I seen a Dragon used long enough to adequately heat the oil. It'll heat your cylinders and allow your engine to fire off way before the oil is ready to circulate. But it's your motor, do what you want.

    Nothing beats an electric pad heater or a Little Buddy that's allowed to run for several hours. Reiff and Tanis make systems to heat sump and cylinders with heat pads. Bearing supply houses sell relatively inexpensive silicone heat pads that you can stick to your engine with hi-temp silicone. A 75 watt heat pad will warm your oil very nicely. A heat pad and a Little Buddy will both run on a 1000w generator and will allow you to leave while you preheat. That's a nice feature.

    Whatever you use, preheating takes time. You can't get it done in 15 or 20 minutes.

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    I use an MSR multi fuel stove, some tin piping and some scat tubing... poor mans version of the northern companion. I started out using the flexible aluminum dryer ducting... it works well, but the will catch on fire... they burn amazingly well. I got some scat tubing and it hasn't caught on fire yet. I preheat for at least an hour and if it's really cold I shoot for 2 hours. I have an engine cover and at home I also throw a couple old sleeping bags over the top, that seems to help. There is no perfect system. If I had electricity available I would use an engine heater/pad.

  11. #11

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    I agree with Mr. Pid. You need to heat the oil inside the engine. I have use a little buddy heater. I will turn it on at least 3 hours before a flight. When I start the engine it only takes a few minutes to have oil temp in the green. I estimate that the oil and engine and everything else under the cowl is around 80* at startup.

    I also strongly encourage a little buddy in the cabin. Not only does it make getting in the plane more pleasant but it greatly reduces instrument wear and tear. I like to get the cabin heater on at least 2 hours before the flight.

    My other pet peeve is when people spend the time to preheat the engine. Start the plane and then taxi to the fuel and shut down. While fueling and running around they leave the engine uncovered for 30 minutes. Aircraft engines are air cooled, they cool very fast. After 30 minutes at about 5* OAT all preheating is lost.

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    Lightbulb Pre-heating cowling/engine

    I was looking at purchasing a plane last year and the guy used a drop light w/ a 100W bulb (the kind you hang under your car if you work on it). I giggled a little bit at first but when I checked the engine compartmet and oil temp all was good. If you have electric available then it's not a bad way to go. You can plug it in the night before and not worry about a fire. He said it only took a few hours to pre-heat the engine oil with an engine blanket. Our engine was good to go in a couple of hours at -20.

    This is a much cheaper option than dedicated engine heaters.


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    No offense, but I have to call BS. I can use 800w of directly applied heat using a Reiff aircraft-specific preheat system and it won't be ready in 2 hours at -20*F. I've known guys who used drop lights in a pinch by putting one under the cowling the night before. That's marginally effective.

  14. #14
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    Default Cheap heat

    My friends accuse me of being cheap. I like to think of it as being frugal. As a new pilot I find that I have to be frugal in most areas in order to afford to fly.
    I have not used it in really cold weather yet, but a friend goes to the thrift store and buys electric hair driers for engine preheat. You put one in the engine compartment and point it where you want the hot air to go. They are high wattage and move the air around also. I am sure you should keep an eye on it since you are not using it as designed. But for about five bucks it is hard heat to beat. He has had them burn out.
    Another frugal heat source I have heard about but not tried is a thrift store hot air popcorn popper. You would have to use some ducting for this though.
    Use these frugal flier ideas at your own risk. Both put out a lot of heat and could start a fire. I am sure it will take some experimenting to see what works best in your particular airplane.
    For safety and ease of use I would think the aircraft approved heat pads are the way to go.
    Patrick

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    Thanks everyone for the good info above. I also just purchased my first plane and was figurin' out the pre-heat thing when I had to move to a new tie down just as a cold snap hit. Here's how not to preheat:

    I first tried my little camping pocket rocket stove with a piece of dryer flex tubing. This is a great way to simmer a pot of ramen but won't get you far with your engine. It ran on butane/propane mix cylinder which quickly cooled and was no better than holding a lit match at the end of a 4 ft tube under the cowling. Don't use butane/propane mix and expect to get much of a flame.

    I read a good post elsewhere that recommended taking your extinguisher out of the plane and hooking it on your belt while pre-heating with fire. Kind of like "don't carry your gun or bear spray in your pack wile hiking". I thought this was good advice and stick to it myself.

    I finally bought an MSR XKG stove on ebay (the one used with a northern companion), a short section of double walled pipe vent from Lowes and some scat tubing and that has worked great. I use white gas but will try kerosene next time as according to burning specs that will burn hotter and longer and has less fuel volatility.

    Ben

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