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Tilley PL53 / 246 hybrid output

Discussion in 'Fettling Forum' started by KAB, Oct 10, 2016.

  1. KAB

    KAB United Kingdom Subscriber

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    I recently aquired and Tilley 'hybrid' A PL53 base with a 246 Hood & Burner with a home made glass cage.

    1476090577-PL-246_hybrid_lit.jpg

    I have cleaned and flushed it through, but have a burning issue..... Lights beautifully as shown in the picture, but after 10 minutes running the burner starts to glow cherry red and the light output dims considerably whilst still holding good pressure :(

    I have swapped the burner and the hood with newer stock but the problem remains. The only way I can get it to run brightly for any length of time is to run the burner without the hood and glass.

    Any suggestions?
     

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  2. David Shouksmith

    David Shouksmith United Kingdom Founder Member

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    Define "good pressure", please... :)
     
  3. KAB

    KAB United Kingdom Subscriber

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    Good pressure.......

    Trial 1, Given 50 pumps on ignition and run for over half an hour. Hissing sound when releasing the pump to turn off. Light stays at reduced output until hissing almost stopped and fades to out.

    Trail 2, Given 50 pumps on ignition and run for over half an hour. Given a further 25 pumps, still burns at reduced output.

    Both trials repeated, output drops off over first 15 minutes.

    Trial 3, Burner and mantle carefully removed from hood, placed on vapouriser as before. Given 50 pumps on ignition and run for an hour, output stays bright and burner top doesn't glow.

    Trial 4, very carefully reinstall burner and mantle in hood repeat Trial 1 and burner glows again and light output fades.

    Same mantle used throughout. :-k
     
  4. broadgage United Kingdom

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    It sounds as though the fuel/air mixture is burning inside the burner, rather then below the burner and within the mantle.

    Burners do wear out eventually. Although you have tried two, perhaps both are suspect?
     
  5. David Shouksmith

    David Shouksmith United Kingdom Founder Member

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    Hmm, your pressure's a bit low and I'd pump it up more but from the other things you've done, it would seem that's not the issue.

    If it works OK without the hood then that would suggest the issue is something to do with that. It's difficult to imagine the gallery would be so choked that it was impeding airflow but it might be worth a look. Has the hood been modified in some way to allow the homemade globe cage to be attached to it?

    Have you tried substituting a PL53 hood? - preferably from a lantern you know is running well. With that, there's nothing to obstruct the air intakes...
     
  6. Mackburner

    Mackburner United Kingdom Founder Member Subscriber

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    Early Tilley burners are designed to sit directly on the top of the vaporiser and take the full weight of the lantern head. For that reason the burner has a solid rim inside to sit on the vaporiser top. Later burners as for the Guardsman Etc. did not need this internal seat and used like this the vaporiser impacts onto the air intake tubes. This in time bends the brass and restricts the air intake and also means the gas tip is higher in the burner as the vaporiser punches its way up through the air tubes and this affects the mixture. So whilst fitting a later burner head to a PL53 will work, in time it will begin to fail as the burner gets gradually damaged. Fit the correct head and burner.

    ::Neil::
     
  7. David Shouksmith

    David Shouksmith United Kingdom Founder Member

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    Interesting - I knew about that rim inside the burners but I hadn't realised Tilley had done away with it for the X246 series and on - presumably from 1946. Thanks, Neil... :thumbup:
     
  8. James

    James United Kingdom Subscriber

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    So I guess that means it is not possible to use a modern Tilley burner on an old lamp or lantern by replacing the air tubes with the threaded kind?
     
  9. Ian Bingham

    Ian Bingham United Kingdom Subscriber

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    I have no doubt that Neil is correct - but did Tilley use a special rebated modern burner on the late table lamps, such as TL120A?

    If not it would suggest that the air tubes resting on the vapouriser works for a while....
     
  10. JonD

    JonD Spain Subscriber

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    I suspect there is a lot to learn here if we could fathom it out between us.

    A Tilley burner has the 3 air inlet tubes and, assuming they are clear of obstructions, how far above the jet orifice should they be for an ideal mixture?

    Should the burner make good physical contact with the vapouriser tube or should it not? If they are in contact they share heat and one cools the other. It they have no/bad contact which one runs hotter?

    I suspect my recent ballooned vapouriser on an X246B happened because it overheated, the walls went soft, then it swelled up. I don't know why it did it. New vap has walls too thin? Or should it have been bleeding heat up via the burner body which has the flow of cooling air?

    My X246B does have issues with the inner of the burner. I'll not go into details but it got reamed in an unfortunate event. If it had a ledge/rim up there I reckon not much of it is left. I thought it should still be OK since the Hood & Burner position are set by the cage - or?
     
  11. Mackburner

    Mackburner United Kingdom Founder Member Subscriber

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    I am by no means certain when Tilley stopped bothering about the burner sitting on the vaporiser. I only mentioned it because it is a change of the way the enginering has to work. Since 1946 the seat was not required for the lanterns but would have been for the table lamps so it is possible the change was not made until the burner design was altered to the "Modern" type with a collar and pin fitter. At that time the engineering standards were somewhat sloppy and they may well have just ignored the problem. ::Neil::
     
  12. KAB

    KAB United Kingdom Subscriber

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    After some more playing I have decided on one more variation - try a 169 vapouriser which the PL should be using.
    I have now aquired the correct hood and burner. Just need a cage and a 182 globe to return it to near original parts.

    Looking through the gallery I understand it is an early 1930's fount with riser, brass handle lower sections and iron bail with loose spiral handle. The control cock has a Bakelite knob so is a little later.
     
  13. Mackburner

    Mackburner United Kingdom Founder Member Subscriber

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    The Bakelite knob is 1935 and later. So late 1930s not early. ::Neil::
     

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