Husqvarna CCC Ebay Store DHS Online Store

Another chainsaw dyno...

Discussion in 'Chainsaws' started by Red97, May 4, 2020.

  1. Red97

    Red97 Mastermind Approved! GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Jan 2, 2016
    Messages:
    5,575
    Likes Received:
    35,392
    Trophy Points:
    510
    Location:
    MI
    Local Time:
    11:11 AM
    Deflector, then pipe. But I didn't swap them.
     
  2. Terry Syd

    Terry Syd Pinnacle OPE Member

    Joined:
    Jan 18, 2016
    Messages:
    1,415
    Likes Received:
    5,132
    Trophy Points:
    345
    Location:
    Comboyne, NSW Australia
    Local Time:
    1:11 AM
    It would be interesting to discover WHY that was the case. Most people on this forum seem to be enamored with making the exhaust port as wide as possible. Forgetting perhaps the possibility of 'short circuiting' with the transfer ports.

    So this is where the dyno comes into it's own. Run the jug and get a reading, then widen the exhaust port to get more time/area and expect an increase in power higher in the powerband - only to go backwards.
     
    Last edited: May 22, 2020
  3. Bigmac

    Bigmac Here For The Long Haul!

    Joined:
    Apr 19, 2018
    Messages:
    3,756
    Likes Received:
    23,780
    Trophy Points:
    495
    Location:
    Oregon
    Local Time:
    8:11 AM
    Agreed! And same with the muffler, the smaller deflected muffler made more than the wide open pipe outlet.
     
  4. legdelimber

    legdelimber Super OPE Member

    Joined:
    Jan 14, 2019
    Messages:
    173
    Likes Received:
    406
    Trophy Points:
    108
    Location:
    N.C.
    Local Time:
    11:11 AM
    Interesting how one saw has the slight bumps in the curve at the 10500~11000 and roughly-ish 11500 to 12000 rpm while the other has the small dip in same regions.

    Also makes me curious what you would see in an audio chart. Does the exhaust note get any sharper or fuzzy at any peaks and dips? That and how does the intake "snort" vary across the rev range.

    Bah. I'm starting to sound A.D.D. again I guess.
     
    MustangMike and Red97 like this.
  5. mgr1

    mgr1 Super OPE Member

    Joined:
    Dec 27, 2016
    Messages:
    290
    Likes Received:
    623
    Trophy Points:
    193
    Location:
    Belgium
    Local Time:
    5:11 PM
    Smaller exhaust port, higher velocity of outgoing exhaust, higher velocity incoming fuel?

    Think that a bigger exhaust port is more for a tuned pipe.
     
    MustangMike, Woodpecker and Red97 like this.
  6. Red97

    Red97 Mastermind Approved! GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Jan 2, 2016
    Messages:
    5,575
    Likes Received:
    35,392
    Trophy Points:
    510
    Location:
    MI
    Local Time:
    11:11 AM
    2nd most power of any of the hybrids is a 73cc with 8.5hp widest exhaust I've ever run 74% I believe.

    Maybe the big pipe would have made more on the high up saw? Didn't hardly give time to experiment. Test them, clean an ship them out.

    Screenshot_20200523-044922.jpg I am 98% those spikes are the 4 stroke to 2 stroke clean up area. I can hear it during a pull.

    Pulling from the top down, the saws are 4 stroking just like being held above the wood. Apply load the little spike is where they clean up.

    Red line saw hit really hard, believe the second spike is just a ripple effect from me trying to load the saw down.



    Running this load valve is just like fishing....


    When a monster hits, you really gotta get on the valve.

    Stock saws you can reel in and stall very easy.
     
  7. drf256

    drf256 Dr. Richard Cranium (“RC” to Muh pals) GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Dec 29, 2015
    Messages:
    7,717
    Likes Received:
    51,143
    Trophy Points:
    573
    Location:
    Strong Island NY
    Local Time:
    11:11 AM
    Looks great Joe. I’m sure you are learning a lot.
     
  8. jacob j.

    jacob j. Beezlebubba GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Dec 24, 2015
    Messages:
    5,702
    Likes Received:
    39,389
    Trophy Points:
    583
    Location:
    Coastal Oregon
    Local Time:
    8:11 AM
    He's dragging us along with him, and it's an excellent ride.
     
  9. srcarr52

    srcarr52 Professional over thinker. GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Jan 12, 2016
    Messages:
    2,405
    Likes Received:
    15,313
    Trophy Points:
    445
    Location:
    Iowa City
    Local Time:
    11:11 AM
    I think pipe outlets tend to have a spot in the power curve where they over scavenge. All depends on the length of the pipe.
     
  10. Billy Currie

    Billy Currie Pinnacle OPE Member

    Joined:
    Sep 21, 2018
    Messages:
    333
    Likes Received:
    1,263
    Trophy Points:
    208
    Location:
    Asheboro, NC
    Local Time:
    11:11 AM
    I like the results.
     
    MustangMike and Red97 like this.
  11. Duane(Pa)

    Duane(Pa) It's the chain...

    Joined:
    Dec 30, 2015
    Messages:
    3,681
    Likes Received:
    17,439
    Trophy Points:
    408
    Location:
    Centre County
    Local Time:
    11:11 AM
    Pretty dang cool that it has such good resolution to see the four stroke, two stroke transition graphically.
     
    MustangMike, drf256, lauren and 3 others like this.
  12. TreeLife

    TreeLife I still like saws GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Jan 24, 2017
    Messages:
    3,649
    Likes Received:
    16,484
    Trophy Points:
    417
    Location:
    Berkshire County, Massachusetts
    Local Time:
    11:11 AM
    Dragging? Chit, can't drag the willing lol
     
  13. legdelimber

    legdelimber Super OPE Member

    Joined:
    Jan 14, 2019
    Messages:
    173
    Likes Received:
    406
    Trophy Points:
    108
    Location:
    N.C.
    Local Time:
    11:11 AM
    Start thinking about the muffler like it's a whistle.

    Let's not forget the shapes of holes in musical instruments.
    Then go to the math that folks use to figure out standing waves & null points of audio in room installations.

    Look at the resonances and do some math on harmonics and half and partial frequencies, etc.
    Remember that trick of a resonating string next to the one you were tuning on a guitar? That's a harmonic energy affecting another thing.
    Happens in gasses too.
    If something has (a) mass or an energy wave/pulse, then it it can be exploited.
    oh crap! now we're drifting back into burned & unburned fuel & oil weights and temperatures.

    ...betcha the effects of mufflers and outlets will start to make more sense though huh.

    Same trick behind that goofy chamber in the Dolamr mufflers.
    Stuffed up muffler, but it gives a canceling pulse to the exhaust and passes emissions needs.
    Now..., maybe go find a way to use it to your advantage?

    Read something in a motorcycle magazine in the 70's.
    I think it was Morbidelli that pulled some amazing (for the time) peak hp out of their small 2-cycle engines (road racers) with this musical thinking.
    Magazine article claimed that they actually pulled a guy in who came from musical instrument design.
    Kinda wish I still had some of those old magazines now.
     
    Last edited: May 24, 2020
    MustangMike, lauren and Red97 like this.
  14. Dieselshawn

    Dieselshawn Super OPE Member

    Joined:
    Feb 6, 2016
    Messages:
    179
    Likes Received:
    655
    Trophy Points:
    153
    Location:
    Southern Ontario, canada
    Local Time:
    11:11 AM
    Now that’s a nice dyno. :)
     
  15. ferris

    ferris Pinnacle OPE Member

    Joined:
    Feb 12, 2016
    Messages:
    616
    Likes Received:
    2,441
    Trophy Points:
    255
    Location:
    Germany
    Local Time:
    5:11 PM
    So which saws are that?
    Red is 73cc???
    Yellow is ???
     
    MustangMike and Red97 like this.
  16. Red97

    Red97 Mastermind Approved! GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Jan 2, 2016
    Messages:
    5,575
    Likes Received:
    35,392
    Trophy Points:
    510
    Location:
    MI
    Local Time:
    11:11 AM
    Red 79
    Yellow 86
     
    MustangMike, jacob j., ferris and 2 others like this.
  17. Dieselshawn

    Dieselshawn Super OPE Member

    Joined:
    Feb 6, 2016
    Messages:
    179
    Likes Received:
    655
    Trophy Points:
    153
    Location:
    Southern Ontario, canada
    Local Time:
    11:11 AM
    Looking back, I never thought about Land and Sea dynos.

    I do know they have them for snowmobiles but never thought about lawn mower size units.

    Then would’ve had everything that come with the unit with additional options.

    The dyno I built is the almost the same type, just hydraulic oil driven through a gear pump.

    Works really well and has been reliable. Just have to hand calculate the numbers to make a graph.

    I also like the fact I don’t have to keep looking for logs to cut and human, chain sharpening inconsistencies that can throw numbers out the window.

    Also, no mess to clean up.
     
  18. Red97

    Red97 Mastermind Approved! GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Jan 2, 2016
    Messages:
    5,575
    Likes Received:
    35,392
    Trophy Points:
    510
    Location:
    MI
    Local Time:
    11:11 AM
    Yep, I was just going to build one, by the time I got everything priced and remotely close to something. It was already expensive.

    With no guarantee it would even work.

    This land and sea kart dyno showed up. Close enough to my budget to make it work.

    When I called they said it would be just over 6k for the dyno setup.

    And still have to buy software, and make the test stand.
     
  19. Dieselshawn

    Dieselshawn Super OPE Member

    Joined:
    Feb 6, 2016
    Messages:
    179
    Likes Received:
    655
    Trophy Points:
    153
    Location:
    Southern Ontario, canada
    Local Time:
    11:11 AM
    That’s actually way over my budget what I can afford for the limited work I do.

    I do know the dyno can pay itself off over time through dyno use for customers or testing equipment operation.

    Dyno Days can make some cash too.

    Cutting logs uses up chains, files, time to get the log, transport, clean up etc.

    On my dyno, I can disassemble the saw on the machine, change something and put back together without taking the bottom end off the mount.

    Makes it fun :)
     
  20. Red97

    Red97 Mastermind Approved! GoldMember

    I Support This Forum as a Gold Member!
    Joined:
    Jan 2, 2016
    Messages:
    5,575
    Likes Received:
    35,392
    Trophy Points:
    510
    Location:
    MI
    Local Time:
    11:11 AM
    Already learning things I would have still been only speculating about without it.

    Plan to do a bunch of runs this week.
     
Loading...

Share This Page

Loading...
  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice