Page 1 of 2 12 LastLast
Results 1 to 20 of 31

Thread: DIY Engine Preheater

  1. #1
    Member
    Join Date
    Jan 2010
    Posts
    96

    Default DIY Engine Preheater

    I came across this on youtube. It looks like it might work. There seems to be no end of things you can do with a .50 cal ammo can.

    http://www.youtube.com/watch?v=_5bK_ivwXs4

  2. #2
    Member
    Join Date
    Jan 2007
    Location
    Semi-retired in Florida
    Posts
    483

    Default

    Quote Originally Posted by tralika View Post
    I came across this on youtube. It looks like it might work. There seems to be no end of things you can do with a .50 cal ammo can.

    http://www.youtube.com/watch?v=_5bK_ivwXs4
    No thanks . . . . .

  3. #3
    Member avidflyer's Avatar
    Join Date
    May 2007
    Location
    Soldotna
    Posts
    222

    Default

    Why not Grizz?

    I have seen and used alot more rudimentary preheaters that that out in the field. Tough to get a good heater that is light weight, needs no electricity and will run off any type fuel you can find. I think it is a pretty good idea, and is close to what I use, however, mine is based on an old 5 gallon blazo can so I can put the stove and heater hose all inside.

    I'm going to use up one of my old ammo cans and see how it works.

  4. #4
    Member
    Join Date
    Jan 2007
    Location
    Semi-retired in Florida
    Posts
    483

    Default

    Quote Originally Posted by avidflyer View Post
    Why not Grizz?

    I have seen and used alot more rudimentary preheaters that that out in the field. Tough to get a good heater that is light weight, needs no electricity and will run off any type fuel you can find. I think it is a pretty good idea, and is close to what I use, however, mine is based on an old 5 gallon blazo can so I can put the stove and heater hose all inside.

    I'm going to use up one of my old ammo cans and see how it works.
    It's not the can, which I consider a GREAT idea. It's the flexible aluminum dryer vent line. I preferred the Coleman one-burner "plumber's pot" model heat source (about the same thing as is shown) but with a flexible 5 1/2" STEEL heat transfer 'pipe'.

    Just in passing: I've always used those ammo cans for my First Air Kits. Waterproof and virtually indestructable! I may be wrong, but I think pressure applance fuel (BLAZO, white gas) is required for the heater shown.

    The idea is basically a really great one, and I'm gonna build one or two myself!

  5. #5
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    I built one of those about 15 years ago and still use it today. The reason I built it was because the single tube from a Northern Companion was too big to be practical. I thought two smaller ducts would make more sense. I used an ammo box because is what I had handy and made two outlets for hi-temp scat tube to fit over to route the heat to the engine. For a Cub one tube to each cheek cowl. For a Cessna one tube into each cowl flap. My scats store (compressed) in the bottom of the box and the stove and fuel bottle go in on top of that. Easy to carry and very effective. No pics on this computer, though. Maybe I'll post some later.

  6. #6
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    Here are two pictures.
    Attached Images Attached Images

  7. #7
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    And a third.
    Attached Images Attached Images

  8. #8
    Member avidflyer's Avatar
    Join Date
    May 2007
    Location
    Soldotna
    Posts
    222

    Default

    Quote Originally Posted by Grizzly 1 View Post
    It's not the can, which I consider a GREAT idea. It's the flexible aluminum dryer vent line. I preferred the Coleman one-burner "plumber's pot" model heat source (about the same thing as is shown) but with a flexible 5 1/2" STEEL heat transfer 'pipe'.

    Just in passing: I've always used those ammo cans for my First Air Kits. Waterproof and virtually indestructable! I may be wrong, but I think pressure applance fuel (BLAZO, white gas) is required for the heater shown.

    The idea is basically a really great one, and I'm gonna build one or two myself!

    Mine looks just like that and it is a multi fuel stove. Blazo, mogas, avgas, about anything that will burn will work in it.

    http://www.rei.com/product/709000

  9. #9
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    Here's an even simpler heater using a Coleman stove and some duct parts from Home Depot. This one works well, too.
    Attached Images Attached Images

  10. #10
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    My ammo box heater uses an MSR multi-fuel XGK Expedition stove. Another option is the Dragonfly model. Those two are the highest output MSR stoves I've used. My Whisperlight can't keep up with the XGK for heat output. The little Coleman is dual fuel. They all work best of white gas but will burn avgas in a pinch.

  11. #11
    Member
    Join Date
    Jan 2010
    Posts
    96

    Default

    Whatever type of heater you use I suggest putting a fine wire mesh screen at the bottom of the hose or tube that directs the heat to to the engine. If the stove flares up, the flame will not go through the wire mesh. Same principle as the old miner lamps.

  12. #12
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    The stoves I use roar pretty good when the flame is working properly. In fact even as the pressure and fuel get low mine have been perfectly safe in their respective boxes. I won't add any screen because it'll reduce air flow. In my time using my heaters no screen has been necessary. But I won't leave any combustion type heater unattended. Whenever possible my first choice for preheat is electric, and I stay indoors where it's warm.

    Part of the reason I made my ammo box heater was because Red Dragon heaters are dangerous. I'll take my ammo box over a Red Dragon any day.

  13. #13
    Member
    Join Date
    Jan 2007
    Location
    Semi-retired in Florida
    Posts
    483

    Default

    Quote Originally Posted by tralika View Post
    Whatever type of heater you use I suggest putting a fine wire mesh screen at the bottom of the hose or tube that directs the heat to to the engine. If the stove flares up, the flame will not go through the wire mesh. Same principle as the old miner lamps.
    Really? Thanks . . . . .

  14. #14
    Member RocketRick's Avatar
    Join Date
    Apr 2010
    Location
    ANC
    Posts
    410

    Smile

    Boy what a timely thread. I was just looking to buy one for the 180B.

    Hmm..I have an old Svea stove I used to use backpacking but it let me down once across the Mat-Su River from Sheep Lodge so I got the Whisperlite.

    Maybe I'll make one.

    Question;

    What is the cutoff temp you guys think one needs to use a preheater? Below freezing or?

    Rick

  15. #15
    Member
    Join Date
    Jan 2007
    Location
    Semi-retired in Florida
    Posts
    483

    Default

    Quote Originally Posted by RocketRick View Post
    Boy what a timely thread. I was just looking to buy one for the 180B.

    Hmm..I have an old Svea stove I used to use backpacking but it let me down once across the Mat-Su River from Sheep Lodge so I got the Whisperlite.

    Maybe I'll make one.

    Question;

    What is the cutoff temp you guys think one needs to use a preheater? Below freezing or?

    Rick
    My own rule was to use heat below twenty degrees above zero. A bit warmer, though, might have saved a bit of battery power.

  16. #16
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    Your 0-470 will probably get really hard to start below about 15*. Especially problematic with a small or old battery. Oil pressure builds more slowly below freezing temps but it gets scary slow below about 10*. Whether I preheat at 30* depends on how much time I have. On a day when it won't get light until late in the morning preheating is less inconvenient. On the other hand if you were planning to go home today and all of a sudden a storm is closing in on you you may be motivated to skip the heating stuff and go. In that case My no-go temp is about 10*, because starting it at colder temps is likely to be a failed exercise. Frosted plugs are a show stopper.

    The common rookie mistake when preheating is not giving it enough time. Air cooled cylinders heat up really quickly. 8 quarts of oil in your sump takes a lot longer. Be patient.

  17. #17
    Member
    Join Date
    Jan 2010
    Posts
    96

    Default

    You really can't go wrong by preheating. The biggest problem in failing to preheat is not just getting the engine started but the accelerated wear when you start a cold engine. The aluminum parts of the engine heat up much faster that than the steel parts. When the crankcase is heating up it expands faster than the crankshaft and camshaft. Until the temperature of the steel parts catch up to the temperature of the aluminum parts the clearances between the parts are way over the service limits. That causes a great deal of wear. That problem is aggravated when the oil is cold and takes longer to flow causing less lubrication. Some folks say you can never preheat the crankshaft because the prop acts like a huge heat sink since it is outside the engine cover. If life were fair every plane would live in a toasty warm heated hanger. Last time I checked life is not fair so it's a good idea to get to the airport early and preheat.

  18. #18
    Member
    Join Date
    Apr 2006
    Location
    Anchorage
    Posts
    3,293

    Default

    Not arguing but am curious. My engine runs with CHTs at around 390*. I assume this is the engine's favorite temperature. With respect to starting temps how do internal parts clearances compare between 35* and 15*? I've never understood why guys pick freezing as the preheat temp. Starting at 70* is cold compared to 390*.

    I'll need to look it up to be sure but I remember both TCM and Lycoming recommendations for preheating start at temps well below freezing.

  19. #19
    Member
    Join Date
    Jan 2010
    Posts
    96

    Default

    Both Continental and Lycoming have Service Information Letters on cold starting. Continental recommends preheat at temps below +20f, Lycoming recommends preheat below +10f. All I know is that engines sound a lot happier when they are preheated anytime the temp is near freezing or colder. Compared to engine failures and engine overhauls, preheating is cheap and easy. Multi grade oil is also a good idea in the winter. This is another one of those things that everyone will have their own opinion based on past experience. My feeling is that assuming you don't light the plane on fire, you can do no harm by preheating.

  20. #20
    Member
    Join Date
    Jan 2007
    Location
    Semi-retired in Florida
    Posts
    483

    Default

    Quote Originally Posted by Mr. Pid View Post
    Your 0-470 will probably get really hard to start below about 15*. Especially problematic with a small or old battery. Oil pressure builds more slowly below freezing temps but it gets scary slow below about 10*. Whether I preheat at 30* depends on how much time I have. On a day when it won't get light until late in the morning preheating is less inconvenient. On the other hand if you were planning to go home today and all of a sudden a storm is closing in on you you may be motivated to skip the heating stuff and go. In that case My no-go temp is about 10*, because starting it at colder temps is likely to be a failed exercise. Frosted plugs are a show stopper.

    The common rookie mistake when preheating is not giving it enough time. Air cooled cylinders heat up really quickly. 8 quarts of oil in your sump takes a lot longer. Be patient.
    Agree! For the "new guys," don't forget that the oil must be thawed through. That is, don't be in such a hurry that a frozen ball remains in the middle of all that oil. Could spoil a guy's whole day . . . . .

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •