8R runtime question

Discussion in 'Stove Forum' started by Mark20s, Oct 25, 2025 at 4:38 PM.

  1. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    Hello everyone, I am looking for precise specifications such as the maximum duration of the tank for this type of stove (8r vesta...). Thank you for reading me and for your future response.
     
  2. alnl1996

    alnl1996 Subscriber

    Offline
    Joined:
    Nov 6, 2007
    Messages:
    893
    Location:
    Ontario, Canada
    When you say duration, do you mean the runtime on a full tank at maximum power on the 8R?
     
  3. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    Yes, that's it, you're right. I would like your feedback on runtime.
    runtime on a full tank at minimum power on the 8R.

    for exemple my stove (8R) have 2 hours runtime, and with this same setting i can heat water at ~140°F in 6 minutes.
    If i take a similar tank capacity SVEA 123 sade that it can burn 45min max

    Thank's in advance
     
    Last edited: Oct 26, 2025 at 6:22 AM
  4. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    My first mod with stainless steel grid and blowtorch head burn e85 gas
     

    Attached Files:

  5. Blackdog

    Blackdog United Kingdom SotM Winner Subscriber

    Offline
    Joined:
    Jan 7, 2009
    Messages:
    3,293
    Location:
    Dreaming of snow
    I'm not entirely sure what you're trying to achieve, but your stove is now producing a lot of carbon monoxide. This will be the case with anything other than a pure blue flame.

    The correct fuel for a No.8r is something similar to naphtha, such as Coleman fuel, Aspen 4T, perhaps a member in your country can advise.

    Automotive fuel is no longer suitable for these stoves due to the ethanol content and other additives.
     
  6. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    Second mod ... 143_0455.jpg
    And see that barely opening

    143_0458.jpg

    Normal flame

    143_0459.jpg

    See différence opening

    143_0461.jpg
     
  7. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    Thank's for reply.
    Yes, I am aware that yellow flame is monoxide. I am actually trying a fuel that seems not to have existed when these stoves were produced...
     
    Last edited: Oct 26, 2025 at 9:36 AM
  8. Blackdog

    Blackdog United Kingdom SotM Winner Subscriber

    Offline
    Joined:
    Jan 7, 2009
    Messages:
    3,293
    Location:
    Dreaming of snow
    There are threads on this site about running the No.8r on alcohol, which would be a good starting point. Nothing I am aware of regarding using a fuel anything like you are trying.

    You would need a different sized jet at least, and bear in mind the safety valve is designed to protect the stove when using the correct fuel, and may not be safe with other fuels.
     
  9. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    21,550
    Location:
    North Carolina
  10. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    If I have to explain my modification : it would seem that the one stainless steel grid surrounding the bell accelerates the arrival of air and eliminates the monoxide particles, the one under the hat seems to burn the monoxide a second time, did I answer ?
    This burner is silent ! not fully powerfull at this time
     
    Last edited: Oct 26, 2025 at 11:32 AM
  11. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    Yes I am currently using a 0.3mm nozzle, I should receive a batch of 0.5 to 2mm, I will keep you informed of the results
     
  12. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    So I put the cap back on.
    I adjusted the top grid incorrectly (hence the lack of flame in one spot). This creates an escape route for the carbon monoxide.

    So at this point, I definitely have carbon monoxide escaping (invisible).
    I'm still at 85% ethanol and 15% gasoline. (here 0.65€/l 0.56GPB/l)

    Third semi-silent mod (original cap position)

    143_0463.jpg

    143_0467.jpg

    Réglage très fin
    143_0468.jpg
     
    Last edited: Oct 26, 2025 at 1:10 PM
  13. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    Last test with the latest configuration :
    Honestly, no carbon monoxide smell (it's certainly present, odorless, and invisible) - I confirm the runtime of full tank is more than 2 hours 30 minutes (between 2 hours 30 minutes and 2 hours 40 minutes)... During this test, I heated water to 60°C (140°F) in 5 minutes...
    143_0471.jpg 143_0472.jpg 143_0473.jpg 143_0474.jpg
     
  14. ArchMc

    ArchMc SotM Winner Subscriber

    Offline
    Joined:
    Jul 25, 2004
    Messages:
    4,566
    Location:
    Mojave Desert, California
    I also do not understand. The flame in your photos doesn't look strong enough to cook anything.
     
  15. Mark20s France

    Offline
    Joined:
    Saturday
    Messages:
    10
    Location:
    france
    So, with a normal setting, I reached 288°C (550°F) in 1'35 minutes on a plate that didn't have any soot (flame side)...
    For now, my tests are for endurance; I don't claim to be more efficient in terms of power.

    143_0480.jpg 143_0483.jpg
     
  16. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    21,550
    Location:
    North Carolina
    I have always assumed that any burn time rating was associated with a real legitimate flame. Candle flame does not count.
     
  17. hikerduane

    hikerduane Subscriber

    Online
    Joined:
    Mar 1, 2010
    Messages:
    10,557
    Location:
    Plumas County, CA
    I wonder too, purpose of a candle flame or real low flame?
    What was the question? Seems poster answered their own question if it was a question.
    Duane
     
  18. HunterStovie United States

    Offline
    Joined:
    Mar 11, 2015
    Messages:
    1,017
    Location:
    Town of Parker, Colorado, USA
    Adding the screen around the burner bell restricts the airflow not accelerating it. The only way to "accelerate" the air would be to run a long chimney like in a lantern to increase the draft. Bigger holes in the bell would add air. The screen under the burner bell might redistribute the fuel air mix more evenly, but again it's restricting the flow. If the poster is looking for longer run time, turn the flame down. If the poster is looking to run alcohol, then there are better methods. If this was an experiment for the sake of an experiment, I get that, but I don't see any benefits of modifying the existing stove in this manner.
     
  19. alnl1996

    alnl1996 Subscriber

    Offline
    Joined:
    Nov 6, 2007
    Messages:
    893
    Location:
    Ontario, Canada


    Honestly I can’t answer your question, I have never put a stop watch next to a stove..any of my stoves. I just enjoy them as is.
     
    Last edited: Oct 28, 2025 at 10:39 PM
  20. snwcmpr

    snwcmpr SotM Winner Subscriber

    Offline
    Joined:
    Nov 16, 2011
    Messages:
    21,550
    Location:
    North Carolina
    I judge efficiency by fuel usage amounts.