Page 2357 of 2365 FirstFirst ... 1357185722572307234723552356235723582359 ... LastLast
Results 35,341 to 35,355 of 35470

Thread: ESE's works engine tuner

  1. #35341
    Join Date
    13th December 2018 - 18:06
    Bike
    1983 yamaha rd 250
    Location
    sweden
    Posts
    187
    As I said i'm not excactly sure why that engine made more power. And also as I said, I think it had a shared pipe with a y- section to the cylinders, so there is no need to have ducts from one cylinder to the other. If your idea works with separate pipes, I don't know.

  2. #35342
    Join Date
    4th September 2017 - 10:39
    Bike
    Daelim besbi 2008
    Location
    España
    Posts
    232
    Quote Originally Posted by andreas View Post
    As I said i'm not excactly sure why that engine made more power. And also as I said, I think it had a shared pipe with a y- section to the cylinders, so there is no need to have ducts from one cylinder to the other. If your idea works with separate pipes, I don't know.
    sorry, I did not say anything that it is for separate pipes, also it can be controlled with a valve that activates or deactivates it.
    With a little imagination we can dream of a Yamaha TZ250 type engine, powered by the 24/7 valve system, in addition to cross-feed "supercharging" through the exhaust, with a considerable increase in power.


  3. #35343
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,102



    This is the work I would like to have done myself in my own shed if I was clever enough.....



  4. #35344
    Join Date
    13th December 2018 - 18:06
    Bike
    1983 yamaha rd 250
    Location
    sweden
    Posts
    187

  5. #35345
    Join Date
    12th October 2016 - 01:24
    Bike
    1964 Vespa GS
    Location
    San Francisco
    Posts
    76
    started a new thread for geeking out on the CFD details:

    https://www.kiwibiker.co.nz/forums/s...-(CFD)-Q-amp-A

    Thinking this will make it easier to track and find the boring data like gas properties and how to generate good mesh boundary layers, and then we can just post the results and exciting stuff here.
    Patrick Owens
    www.OopsClunkThud.com

  6. #35346
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,102
    More intriguing stuff from the Shed of Two Stroke Stuffing ......


  7. #35347
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,102

  8. #35348
    Join Date
    25th March 2004 - 17:22
    Bike
    RZ496/Street Triple R/GasGas/ etc etc
    Location
    Wellington. . ok the hutt
    Posts
    18,431
    Thanks for posting that Rob. Held 6" from my face my heartrate was going. I love 50s, even on long tracks.
    I've been told. Dreaming`s free.
    Think I'll go, back to sleep.
    Everybody listen, voices in my head
    Everybody listen, do yours say, what mine says?

  9. #35349
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,102
    Quote Originally Posted by F5 Dave View Post
    I love 50s, even on long tracks.
    Yes, I am enjoying mine. RG50 in NF4 chassis with a few mods to make it a bit more comfy to ride. I have ridden it at Hampton Downs club track and Tokoroa. Came last every time....

  10. #35350
    Join Date
    13th August 2020 - 20:54
    Bike
    Derbi DRD pro
    Location
    Finland
    Posts
    4

    Extra blowdown STA over piston pin

    Hello everybody,

    I've been reading these super interesting topics here and in pit-lane. Thanks everybody for this great knowledge that is shared in here!
    I'd like to introduce myself before posting anything else. I'm 32 years old guy from Finland and been diving inside 2-stroke tuning "rabbit hole" since I started tuning Derbi engine for Finnish moped endurance class. I'v been working as motorcycle mechanic 15 years, but mainly with 4-stroke street bikes.

    Our endurance team has Derbi Senda DRD Pro with modified Athena power valve cylinder, original pneumatic PV replaced with electronic Aprilia Rave controlled by Ignitech unit.
    I'm now planning new engine version and got new fresh Athena cylinder to avoid mistakes I've done with first one..
    Been practicing with EngMod2t and playing with different variations. We have just built inertial dyno and that is starting to be finally set up smooth enough to fine tune simulation model to correspond.

    Question:
    There has been a lot of discussion about piston pin plugs and how it's benefit varies depending on porting, plug style, ...
    I have still missed following point. Is gaining blowdown specific time area by extending auxliary exhaust ports over piston pin until cylinder center line making more gains than what is given away with unplugged pin hole? Yes, depends on many thing, but can we have some rule of thump in case of modern high performance engine?

    With best regards,
    -Sami-

  11. #35351
    Join Date
    14th April 2011 - 23:44
    Bike
    2008 Yamaha fino
    Location
    Bangkok
    Posts
    242
    Quote Originally Posted by sniemisto View Post
    Hello everybody,

    I've been reading these super interesting topics here and in pit-lane. Thanks everybody for this great knowledge that is shared in here!
    I'd like to introduce myself before posting anything else. I'm 32 years old guy from Finland and been diving inside 2-stroke tuning "rabbit hole" since I started tuning Derbi engine for Finnish moped endurance class. I'v been working as motorcycle mechanic 15 years, but mainly with 4-stroke street bikes.

    Our endurance team has Derbi Senda DRD Pro with modified Athena power valve cylinder, original pneumatic PV replaced with electronic Aprilia Rave controlled by Ignitech unit.
    I'm now planning new engine version and got new fresh Athena cylinder to avoid mistakes I've done with first one..
    Been practicing with EngMod2t and playing with different variations. We have just built inertial dyno and that is starting to be finally set up smooth enough to fine tune simulation model to correspond.

    Question:
    There has been a lot of discussion about piston pin plugs and how it's benefit varies depending on porting, plug style, ...
    I have still missed following point. Is gaining blowdown specific time area by extending auxliary exhaust ports over piston pin until cylinder center line making more gains than what is given away with unplugged pin hole? Yes, depends on many thing, but can we have some rule of thump in case of modern high performance engine?

    With best regards,
    -Sami-
    My answer is a definite YES!
    At Aprilia we mostly tested with unplugged piston pins, as the plugged pins were too expensive.
    Widening the auxiliar ports was done numberous times, and always gave more power!!!

  12. #35352
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,102

  13. #35353
    Join Date
    13th August 2020 - 20:54
    Bike
    Derbi DRD pro
    Location
    Finland
    Posts
    4
    Quote Originally Posted by jamathi View Post
    My answer is a definite YES!
    At Aprilia we mostly tested with unplugged piston pins, as the plugged pins were too expensive.
    Widening the auxiliar ports was done numberous times, and always gave more power!!!
    Thanks Jan for the info!
    Now I can start widening auxiliar ports and think about buying torlon bar later

    Many sources was telling to avoid relieving to pin bores but that must be now considered as old fashion. That was also reason why I abandoned Athena pistons with relief around pin bore.


    Sent from my iPhone using Tapatalk

  14. #35354
    Join Date
    18th May 2007 - 20:23
    Bike
    RG50 and 76 Suzuki GP125 Buckets
    Location
    Auckland
    Posts
    10,102


    Ok. So its drag racing, but a two stroke drag racer. Great two stroke sound at WOT. And also if you pay attention to the technical talk and trip around the work shop you will pickup that its fuel injected. So the fastest 2T drag bike in the world is fuel injected.

  15. #35355
    Join Date
    8th February 2007 - 20:42
    Bike
    TZ400
    Location
    tAURANGA
    Posts
    3,358
    Widening the Aux ports to bore center does two things , increases Blowdown STA and increases port linking to the A Transfer.
    You can reduce the effect of linking by making the Aux duct very shallow in depth at its rear wall next to bore center , and also grinding the port shape with alot of taper upwards from front to back.
    This gives alot of area just as the port opens , with the max pressure differential , but reduces the linking time.
    With capped pins the duct can have much less of a tangential exit angle on the rear , top , corner wall , with a nice sweeping pocket that improves flow and power.

    Be carefull with using Frits idea of using Torlon inserts , that effectively blanks off the pin bore in the piston.
    In the TM kart engines this reduced the access of lubrication from transfer flow into the piston bearing surface , and the pin ends turned blue.
    Jan said that the Aprilia did the same , but I never wanted to find out if the pin bore became unreliable.
    Making tophat CNC steel plugs and having them laser welded into stock pins is cheap , and relaible and just as effective power wise.
    Maybe drilling a hole upward in the bottom of the piston pin boss would fix the issue , again I wasnt keen on destroying a motor if this was unreliable.
    Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.

Thread Information

Users Browsing this Thread

There are currently 26 users browsing this thread. (0 members and 26 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •