Omnilite silencer and underburn

Discussion in 'Stove Forum' started by ArcticFlame, Mar 9, 2015.

  1. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    Underburn by design?

    Some time ago I described my frankie version of a silent burner head for the Primus Omnilite Ti within this thread:

    https://classiccampstoves.com/threads/26152

    1425911984-LW-1.JPG

    In 2014 Primus announced their version of a silent burner cap for the Ti.
    http://www.primus.eu/omnilitetisilencer

    Now it's available in Europe and I was curious to see how it performs.

    Contrary to the pictured product the final head is different both in shape and material.
    It consists of mainly two parts (very thin stainless steel outer cap with a more massive inner cap) and some steel mesh inside.


    1425912032-Parts-1.JPG

    1425912060-Parts-2.JPG

    Besides the recommended jet with 0.36mm for cartridge gas I tried 0.35 and 0.37mm ....but it's only just a matter of time until you get a perfect underburn with this famous growling sound.

    With the original 0.36mm jet as recommended for cartridge gas it takes about a minute of simmering to get into underburn.
    With a 0.37mm jet you run into severe underburn in less than have a minute. Very impressive in some way.
    A 0.35 mm jet leads to just a slightly longer period of simmering before you are locked in underburn again.

    Note:
    The pictures below show the development of underburn with the smaller 0.35mm jet and Primus 4season cartridge gas.

    Pictures for white gas will follow.

    1425912123-U-1.JPG

    1425912143-U-2.JPG

    1425912160-U-3.JPG

    1425912191-U-4.JPG

    1425912213-U-5.JPG

    1425912235-U-6.JPG

    juergen
     
    Last edited by a moderator: Jul 2, 2015
  2. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    White gas performance with the recommended 0.32mm jet was acceptable, no real underburn.
    Running the stove with this small jet and cartridge gas leads to less power and no real underburn similar to white gas.


    First pic shows the 0.32 jet with cartridge gas

    1425912506-32-cartridge.JPG

    The next pics^are white gas only

    1425912543-WG-1.JPG

    1425912844-WG-2.JPG

    1425912864-WG-3.JPG

    1425912880-WG-4.JPG


    Alltogether not what I had expected....

    juergen
     
    Last edited by a moderator: Jun 26, 2015
  3. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

    Offline
    Joined:
    Aug 25, 2009
    Messages:
    10,152
    Location:
    Blackburn, Lancashire, United Kingdom
    On that evidence I'd much rather have the version you constructed Juergen!

    I don't like the look of that underburn at all.

    John
     
  4. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    I'm with you, John.

    I think this head will eventually make it into my collection of interesting designs

    juergen
     
  5. geeves

    geeves New Zealand Subscriber

    Offline
    Joined:
    Sep 29, 2009
    Messages:
    5,663
    Location:
    Christchurch NZ
    try it without the wire mesh
    On all my experiments with a msr dragonfly and silent from a gas stove underburn was instant until I removed the mesh from the gas head.
     
  6. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    Of course I have tried it without mesh.
    It's even worse.
    Flame lift off and extreme underburn....

    I should mention that the new burner bell comes withou air inlet holes because the head sits too deep, there is no space.
    Air supply only commes from underneath through the five holes around the jet housing.

    juergen
     
  7. Afterburner

    Offline
    Joined:
    Mar 13, 2014
    Messages:
    2,095
    AF thank's for good info and nice pictures!

    I am wondering if those mesh pieces are added later on by Primus when they have noticed that burner cap is not working properly. :doh: Maybe Primus has one or two sea containers full of non working burner caps. 8-[
     
  8. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    :)

    I have no idea.
    And I have never before seen a silent head with mesh inners.

    But whatever they did, it doesn't work.
    Btw, the box says the silencer is made in EU by Primus Eesti OÜ.

    juergen
     
  9. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    14,968
    Location:
    North Carolina
    AF, thank you.
    Are there any dates on the box(s)?

    Ken in NC
     
  10. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    Ken,

    not really.
    Just a picture.

    1425992675-Sil-1.JPG

    juergen
     
    Last edited by a moderator: Jun 26, 2015
  11. Afterburner

    Offline
    Joined:
    Mar 13, 2014
    Messages:
    2,095
    Have you looked inside the box for a date? Stove boxes seems have stamped date on inner surface of the box.
     
  12. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    18. 02. 2015

    Quite new :)

    There was no information sheet or something like that.
    Just a small bag to carry the item.
    That's all.

    juergen
     
  13. presscall

    presscall United Kingdom SotM Winner SotY Winner Subscriber

    Offline
    Joined:
    Aug 25, 2009
    Messages:
    10,152
    Location:
    Blackburn, Lancashire, United Kingdom
    ArcticFlame said

    It's an arrangement that works pretty well on a Tilley CS56 .

    I don't know about any size differential, but there's a strong resemblance between the Tilley cap and the Omnilite silencer. Maybe if the Omnilite was constructed on Tilley lines ... :lol:

    1426000349-Tilley.jpg

    John
     
    Last edited by a moderator: Jul 2, 2015
  14. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    14,968
    Location:
    North Carolina
    Some results of a short search for info of the Primus Silent cap.

    KlITyOOX5Sw[/media]]Berniedawg video
    Primus No 2 restoration after buried in ice 33 years

    German online magazine
    (Find the link on the right side .... "Primus OmniLite Silencer: Schalldämpfer für Benzinkocher"
    English translation by Google:
    Ken in NC
     
    Last edited by a moderator: Jul 2, 2015
  15. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    John,
    thanks for the Tilley link, I was not aware of this wonderful stove.
    I learned that the Tilley behaves similar to the Primus without mesh: Flame lift off.
    I could control that with reduced gas supply.
    But at the price of less power.

    At least your Tilley does not underburn.
    That's the difference.


    Ken,
    thr pics I have seen from Friedrichshafen 2014 are showing a different head....

    juergen
     
  16. Knight84

    Offline
    Joined:
    Jan 21, 2009
    Messages:
    3,234
    Looks like Primus needs to do some more work
     
  17. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    Knight84,

    I absolutely agree with you.
    Primus should be able to design a working silencer which does not even come close to underburn....

    If you take a look at the "magazine" Ken mentioned (it's part of the marketing of an outdoorshop in Germany....) you can see that the picture on top of the article shows a different head as well as the one on the box does.

    Seems as if they changed the design from a probably working one to the current version.

    juergen
     
  18. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    14,968
    Location:
    North Carolina
    I heard, from a good source, it is possibly recalled. Not available from Primus at this time.

    It really puts the making of a silent cap into perspective. Gary did a lot of trial and error to get his design down. It would seem that Primus has the resources to do that, but....

    Ken in NC
     
  19. ArcticFlame

    Offline
    Joined:
    Oct 7, 2010
    Messages:
    139
    Ken,

    yes, the Bernie caps are outstanding.
    I have some of the older handmade versions.
    In my Nova I run them on cartridge and white gas.
    Simmers without any of the symptons of the Primus silencer.....

    We will see.

    juergen
     
  20. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    14,968
    Location:
    North Carolina
    I was a day late and a dollar short to get his hand made caps.
    Ken in NC