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"Today we have naming of parts" - Brit Army No.2 (Modified) stove

Discussion in 'Military' started by presscall, Jul 31, 2013.

  1. presscall

    presscall United Kingdom Subscriber

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    Visualising an initial introduction to the Lee-Enfield rifle by a Sergeant instructor to new recruits early in WWII soldier-poet and later playwright, writer and broadcaster Henry Reed wrote,


    The parts

    1375302203-IMGP5923.JPG


    The parts assembled - front elevation

    1375302422-IMGP5926.JPG


    ... and (right) side elevation

    1375302445-IMGP5931.JPG


    Plan view, breech stove drawer open

    1375302473-IMGP5928.JPG


    ... and closed

    1375302487-IMGP5929.JPG


    Stove (packed)

    1375302514-IMGP5935.JPG


    Ventilation holes, base. Also useful for fuel and slops drainage for those who haven't got the knack (see COOKER - REFUELLING and COOKER - USE OF)

    1375302527-IMGP5933.JPG


    Night ops accessory kit

    1375303650-IMGP5936.JPG


    Ok, I don't propose to sustain the gag throughout this post, but the pristine state of this unused 'No.2 (Modified)' stove from 1989 ...

    1375303158-IMGP5937.JPG


    ... and the military connection suggested the appropriateness of that poem from Henry Reed.

    I'll not be firing up this example, which is too good an opportunity to miss exploring and continuing to enjoy its 'as issued' state. I've had a rough one of these and gave it away, the burner subsequently finding its way to BernieDawg, who really got to grips with it, here but more on Gary's thoughts about the burner later

    It's the burner that's most distinctive part of the stove for me because of its flaws, of which there are quite a few.

    Take the slotted outer cap

    1375303935-IMGP5944.JPG

    1375303970-IMGP5940.JPG


    I'm not grumbling about the half-hearted clearing-out of machining swarf

    1375304012-IMGP5941-001.JPG


    No, it's more major issues than that, one of which is that the in-turning lip of the base of the cap ...

    1375303858-IMGP5947.JPG


    ... together with the contours of the part of the burner in which it sits

    1375304119-IMGP5949.JPG


    ... combine (when the burner's been fired and unequal thermal expansion has taken place) to create a fit matched only for tightness by cooper's hoops on barrels or steel tyres on cartwheels - all shrunk fit on cooling from hot


    1375304434-IMGP5951.JPG


    Does it matter?

    Not a huge amount, but access to the jet nipple by the sensible route and with the tool supplied with the stove is then impossible without prising off the cap (with some difficulty) and requires another tool of which Henry Reed might have said if checking out the stove's inventory "Which in our case we have not got

    In this sequence I used yet another tool (an eraser-tipped pencil) to set the needle to the right number of 'clicks'. It was set way out at the factory - two clicks - and something about the burner spindle and housing geometry made a whopping five clicks ok (3 to 4 is usual for an Optimus 111 burner, say)

    1375304847-IMGP5950.JPG


    1375304894-IMGP5961-001.JPG


    1375304916-IMGP5962.JPG

    1375304942-IMGP5963.JPG

    1375304961-IMGP5939.JPG

    MORE 'NAMING (AND SHAMING) OF PARTS' TO FOLLOW

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

    presscall United Kingdom Subscriber

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    The permanently jammed-on burner cap is an annoyance but the fuelling characteristics of the burner are the most unsatisfactory aspect of the stove in my view as someone who prefers for regular use to use better designed and operating stoves than this one.

    Ok, it gets a pot hot (and the fuel tank as well) so it's fit for purpose and I suppose it was only the onset of diesel throughout the army fleet that killed it off in favour of the diesel-burning No.12, so a lot of No.2's cranked out the dinners and cuppas and would still be doing so.

    Blue flames aplenty come out of those characteristic slots in the cap but also a lot of soot and yellow flames too. Why?

    BernieDawg did a masterly job in his 'hotrodding' post on two of these burners. He diagnosed that too little air was mixing with the vapourised fuel before fuel and air reached the combustion space. Reasonably enough, he judged that the spigot tube through the burner head was too narrow.

    On replacing that spigot tube with larger-diameter tubing in the first of the burners results were still disappointing, so on the second of the burners he raised the whole burner head on lengthened vapouriser tubes, as well as the larger-diameter spigot tube. More air mixed with the fuel, combustion perfect.

    Comparison here with a Radius regulating burner (admittedly a paraffin burner, so discount the greater number of vapourising tubes than necessary for a petrol burner) shows the miserly dimensions of spigot and vapourising tubing on the No.2 burner and the shorter distance (and opportunity) the fuel stream out of the jet has to draw in air

    1375306639-1.JPG


    1375306646-2.JPG


    1375306653-3.JPG


    Other gripes?

    Pipe fitting on burner base is a bit weak and the compression joint tends to require tightening often due to the stresses and leverage levied on it by the heavy burner its supporting and the control spindle operating tool. I had one of these where repeated tightening by a squaddie had crushed the compression 'olive' to the extent that no more tightening was having an effect and the whole burner spun around on the fitting

    1375306662-4.JPG

    1375306675-4a.JPG


    Handsome, well-crafted heat shield (and control tool stowage place) ...

    1375306794-11.JPG


    ... but convected heat in the fuel feed pipe to the burner largely negates the benefits of the heat shield and the fuel tank gets uncomfortably hot in use. It's a very small fuel tank, so there's that much less of a reservoir of cooler fuel to keep fuel tank and fuel temperature moderate.

    It's a very small fuel tank for such a powerful burner. The Turley and Williams stove tank here is from a stove of the same stove case dimensions as the No.2 but without the feature of a slide-out-slide-in fuel tank. It's that that made it necessary to make the fuel tank smaller

    1375306684-5.JPG


    More parts

    1375306701-6.JPG 1375306721-7.JPG 1375306734-8.JPG 1375306753-9.JPG 1375306781-10.JPG 1375306811-12.JPG 1375306829-13.JPG 1375306846-14.JPG 1375306863-15.JPG 1375306886-16.JPG


    Great windshielding - though not a lot of point in that I'll grant when it's not going to be fired up

    1375306905-17.JPG

    John
     
    Last edited by a moderator: Jun 27, 2015
  3. Rick b

    Rick b United States Subscriber

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    Hi John. Great tutorial and photos on the no.2.
    Your first photo looks like my junk drawer at home though. :D

    Best, Rick
     
  4. David Shouksmith

    David Shouksmith United Kingdom Subscriber

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    Excellent stuff as usual, John, but one small point:-

    Did you mean conducted heat?

    Regarding removing the burner cap, I was informed by BNK that this was more easily achieved when the burner was hot. That would make sense but I never got around to trying it - someone wanted to buy my No.3 and I was ready to sell. I think I do still have my Nos. 2 and 12 around somewhere, though...
     
  5. presscall

    presscall United Kingdom Subscriber

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    I had a think about how heat is transmitted to the fuel in the tank and plumped for convection currents in the liquid - but I'll grant conducted heat through the pipe walls and directly to the fuel contribute, and probably more so on second thoughts.

    John
     
  6. Deo United Kingdom

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    Hi,
    Having just read these pages it has enabled me to repair my cooker with some good old fashioned brazing.
    The only thing I am stuck for is the grey washer type thing which is in the control screw. I have no idea what it is made of but looks and feels a bit greasy.
    Basically it has dropped to bits and obviously it now leaks fumes (which light up :-( ) can anybody tell me what it is made of and where I can get a replacement ?

    FYI (It goes on the shaft just behind what looks like a metal thrust washer and seals the control shaft).
    Sorry about my terminology as I don't know the correct names for these things.

    Pretty please :-)
    (Hope you don't mind me using your picture Presscall)
    upload_2016-9-11_16-33-38.png

    Thanks

    Deo
     
  7. presscall

    presscall United Kingdom Subscriber

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    @Deo
    Welcome to CCS.

    It's made of graphite and is a traditional seal for control spindles in regulated burners - this and Swedish ones too. Tightening that nut it's enclosed by expands it and makes the seal but there's not too much friction created (thanks to its being graphite) to prevent the control spindle from turning - provided the nut's not tightened too hard.

    Site sponsor Fettlebox should have one to suit.

    John
     
  8. Deo United Kingdom

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    Hi John,

    Thanks for the reply and the info. I did have a look on fettlebox but I couldn't see one.
    They have a the seal kit but I can't seem to find that graphite seal.
    If you know where it is on the site can you please let me know or I will try and contact them to ask (If you can tell me which seal it is ;-) )

    Thanks Again

    Deo
     
  9. Wim

    Wim Belgium Subscriber

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    Hi Deo, if you look at the picture top right hand of this page, it's the grey strip at the bottom. One just simply rolls the required amount around the spindle!

    Best regards,

    Wim

    PS.; welcome on board!
     
  10. Deo United Kingdom

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    Hi Wim,
    Thanks for the info. I was looking for an actual round seal ...doh. Oh well every day is a school day :-)

    Thanks for the welcomes and the quick responses to both of you.

    Kind Regards

    Deo
     
  11. ArchMc

    ArchMc United States Subscriber

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    @Deo Welcome to the forum.

    The original graphite gaskets were "actual round seals" sized for the valve spindles of various stove models. These are difficult to find now. The graphite sheets are a workaround, but seem to work fine.

    ....Arch
     
  12. Deo United Kingdom

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    Thanks for the info Arch
     

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