Single cylinder OHV - "Snöffy"

Discussion in 'Finished Projects' started by srobovak, Oct 7, 2019.

Help Support HMEM by donating:

  1. Oct 7, 2019 #1

    srobovak

    srobovak

    srobovak

    Member Project of the Month Winner

    Joined:
    Mar 7, 2012
    Messages:
    6
    Likes Received:
    17
    Hi HMEM,


    I have been working on this one for over 4 years now and it finally came to a successful end...

    After researching numerous builds from other people and combining things together I eventually distilled my own engine design.
    I wanted to work in the metric system and also wanted to adjust the size of the model and its complexity to my own demands. As most of these models serve only the purpose of pleasing the builder as they come "alive" I also wanted a design that would suit my own aesthetic ideas of how it should look like.

    I opted for the looks of an early 20th century motorcycle single. After about 3 years of irregular work, I had my first test run which was a failure. The engine would not run continuously even though I had a few puffs. I re-evaluated a couple of things and decided to change the cams to milder timing characteristics, enlarge the flywheel, improve the valves and their sealing and also improve the sealing of the carburetor. This work took me about 5 more months to complete.
    But the second try was an immediate success. The engine now starts really easily and runs quite well. The RPM range is quite narrow though - it idles at around 950 RPM and reaches its maximum at 1800 RPM.
    It also needs some time to rev up and down this range which is due to the large flywheel. I am also pleased with the way it sounds which was also one of my goals.

    Some engine details:

    - the square design of 25 mm stroke to 25 mm bore
    - spark plug ignition using NGK CM-6
    - home-brewed stand-alone ignition module using automobile coil
    - O.S. 1A carburetor
    - running on Coleman fuel mixed with 5% 2-stroke oil
    - splash lubrication

    I would like to thank everybody on this forum for your time to share this great hobby with others. Special thanks to Terry (mayhugh1) whose posts helped greatly in finishing this project.

    Till next time. Cheers,

    Branislav

    20190930_165448y.jpg 20190930_165805y.jpg 20190930_170137y.jpg 20190930_170452y.jpg

     
    oilmac, Longboy, sergulbka and 13 others like this.
  2. Oct 7, 2019 #2

    johnmcc69

    johnmcc69

    johnmcc69

    Well-Known Member

    Joined:
    Dec 5, 2011
    Messages:
    254
    Likes Received:
    36
    Beautiful engine & it sounds great!

    Real nice job!

    John
     
  3. Oct 7, 2019 #3

    awake

    awake

    awake

    Well-Known Member HMEM Supporter

    Joined:
    Sep 5, 2019
    Messages:
    88
    Likes Received:
    17
    Gender:
    Male
    Occupation:
    Educator
    Location:
    North Carolina
    Beautiful indeed! I love the mounting using the curved sections.

    Any thoughts about whether you might offer the plans for sale?
     
  4. Oct 7, 2019 #4

    Brian Rupnow

    Brian Rupnow

    Brian Rupnow

    Well-Known Member Project of the Month Winner

    Joined:
    May 23, 2008
    Messages:
    11,723
    Likes Received:
    4,282
    Beautiful engine. One of the nicer ones I've seen.---Brian
     
  5. Oct 8, 2019 #5

    kuhncw

    kuhncw

    kuhncw

    Well-Known Member HMEM Supporter

    Joined:
    Apr 13, 2008
    Messages:
    666
    Likes Received:
    84
    Location:
    USA ILLINOIS
    You've built a very nice looking engine. I like the low rpm idle. Sounds great.

    Chuck
     
  6. Oct 8, 2019 #6

    Cogsy

    Cogsy

    Cogsy

    Well-Known Member Staff Member Global Moderator

    Joined:
    Jul 30, 2012
    Messages:
    2,618
    Likes Received:
    749
    Gender:
    Male
    Location:
    Perth, Western Australia
    Nicely done and runs as nice as it looks. Congrats.
     
  7. Oct 8, 2019 #7

    TonyM

    TonyM

    TonyM

    Well-Known Member Project of the Month Winner

    Joined:
    May 15, 2017
    Messages:
    247
    Likes Received:
    138
    Gender:
    Male
    Occupation:
    Retired
    Location:
    North Bohemia Czech Republic
    Very impressive and a really smooth runner. Sounds lovely.
     
  8. Oct 8, 2019 #8

    tornitore45

    tornitore45

    tornitore45

    Well-Known Member HMEM Lifetime Supporter

    Joined:
    Jan 17, 2009
    Messages:
    768
    Likes Received:
    118
    On top of all compliments given by others I should say I never seen an engine with suck a slow stable idle, one can almost count the revolutions.
    Great work.
     
  9. Oct 8, 2019 #9

    minh-thanh

    minh-thanh

    minh-thanh

    Well-Known Member

    Joined:
    Dec 29, 2016
    Messages:
    510
    Likes Received:
    241
    Location:
    Viet Nam
    The engine sound is great , Great engine and congratulations !
     
  10. Oct 8, 2019 #10

    ShopShoe

    ShopShoe

    ShopShoe

    Senior Member

    Joined:
    Oct 2, 2010
    Messages:
    949
    Likes Received:
    175
    Congratulations. What everyone has already said. Beautiful, well-thought-out design, Runs smoothly and sounds great. Fantastic low-speed idle and smooth throttle response. I wanna make one someday!

    Can anyone give me a hint as to how the name should be pronounced? I'm not good at umlauts.

    --ShopShoe
     
  11. Oct 8, 2019 #11

    peter2uat

    peter2uat

    peter2uat

    Active Member

    Joined:
    Jun 26, 2009
    Messages:
    29
    Likes Received:
    8
    Gender:
    Male
    Occupation:
    retired
    Location:
    Vienna, Austria
    The "Ö" is spoken like the 'e' in "her"
     
    JRR likes this.
  12. Oct 8, 2019 #12

    dethrow55

    dethrow55

    dethrow55

    Well-Known Member

    Joined:
    Dec 24, 2015
    Messages:
    87
    Likes Received:
    15
    Gender:
    Male
    Occupation:
    retired draftsman
    Location:
    el paso texas USA
    hello that is a super nice build.:) any plans for sale? thanks pm me.
     
  13. Oct 8, 2019 #13

    Mechanicboy

    Mechanicboy

    Mechanicboy

    Well-Known Member

    Joined:
    Jul 10, 2013
    Messages:
    672
    Likes Received:
    223
    Same as in norwegian "Ø". Stirling <Støling>, Bird <børd>.. :)

    Nice build engine :)
     
  14. Oct 8, 2019 #14

    plipoma

    plipoma

    plipoma

    Member

    Joined:
    Apr 7, 2013
    Messages:
    11
    Likes Received:
    2
    I would also like to purchase drawings.
     
  15. Oct 8, 2019 #15

    Johno1958

    Johno1958

    Johno1958

    Well-Known Member Project of the Month Winner HMEM Supporter

    Joined:
    Sep 19, 2015
    Messages:
    271
    Likes Received:
    79
    Beautiful engine. Congratulations.
     
  16. Oct 9, 2019 #16

    e.picler

    e.picler

    e.picler

    Edi from brazil

    Joined:
    Jan 3, 2012
    Messages:
    342
    Likes Received:
    220
    Gender:
    Male
    Occupation:
    Administrator
    Location:
    Curitiba - Paraná - Brazil
    Congratulations! Top Noch project and work.
    Very nice low idle.

    Also interested in the plans.

    Edi
     
  17. Oct 9, 2019 #17

    srobovak

    srobovak

    srobovak

    Member Project of the Month Winner

    Joined:
    Mar 7, 2012
    Messages:
    6
    Likes Received:
    17
    I thank you all for your kind words and your interest in this engine.

    One of the most important lessons learned is that one must properly finish the 3D-model and all technical drawings before the machining begins. I was impatient and kept changing and adjusting things as I went along. This means that the drawings are inconsistent and include plenty of mistakes. There are about 20 combination drawings and I would have to revisit them all and probably start with updating the 3D-model itself. I'm on a tight family schedule now and can not afford to do this.

    Maybe I will revisit it someday and compile the set of drawings that I would feel comfortable about and can make public.


    Till next time. Cheers,

    Branislav
     
    Aussie Doc likes this.
  18. Nov 8, 2019 #18

    John Antliff

    John Antliff

    John Antliff

    Well-Known Member

    Joined:
    Aug 7, 2018
    Messages:
    46
    Likes Received:
    31
    Gender:
    Male
    Location:
    New Zealand
    Beautiful engineering. I guess the large mass flywheel is mostly responsible for the smooth slow running just like the full size hit and miss engines heavily rely on the large rotating flywheel mass to keep going. With a single cylinder engine you definitely need a big flywheel!
     
  19. Nov 9, 2019 #19

    SteveM

    SteveM

    SteveM

    Member

    Joined:
    Aug 15, 2010
    Messages:
    7
    Likes Received:
    0
    A truly unique and stunning piece of engineering Branislav, beautifully designed and created. I'd just like to add my name to the long list of people who'd happily pay for the plans if they ever became available.
     
  20. Nov 11, 2019 #20

    oldCB

    oldCB

    oldCB

    Member

    Joined:
    Mar 20, 2015
    Messages:
    5
    Likes Received:
    0
    Absolutely Gorgeous!!
     

Share This Page