Examples of small two stroke dome/squish profile?

Discussion in 'The Garage' started by frascati, Sep 11, 2019.

  1. frascati

    frascati Adventurer

    Joined:
    Mar 23, 2018
    Oddometer:
    38
    Location:
    michigan
    Anyone out there able to post up or give me some links to any files, jpeg, 2dcad, etc, that illustrate some 'typical' dome/squish profiles you'd see on small two strokes? 50 to 80cc. 65cc would be ideal.

    I've got a lathe. With a drawn template I could correct the original head in 20 minutes. I could use software, with bore, stroke, port heights, etc, etc, but it's just a vintage 50cc moped head I'm modifying to match a 65cc cylinder kit so im not after rocket science.

    engine is an "e50" Puch moped engine.

    Thanks.
    #1
  2. anotherguy

    anotherguy Long timer

    Joined:
    Jun 18, 2009
    Oddometer:
    13,893
    Location:
    the hills
    It's a bit more than displacement. I'd begin by verifying squish clearance and correct it to .9-1mm before attempting to modify. If you want to work it out try Gordon Jennings' Two-Stroke Tuner's Handbook. Available in PDF here.
    #2
  3. shovelstrokeed

    shovelstrokeed Long timer

    Joined:
    Jun 20, 2003
    Oddometer:
    5,700
    Location:
    6South Florida
    You bastard!!!
    You just cost me a lot of hours of reading and study time.
    #3
    Beezer likes this.
  4. Dan V.

    Dan V. Been here awhile

    Joined:
    Aug 8, 2013
    Oddometer:
    720
    Location:
    West Michigan
    Oh oh oh - thanks ....I lost my copy. good stuff there!
    #4
  5. anotherguy

    anotherguy Long timer

    Joined:
    Jun 18, 2009
    Oddometer:
    13,893
    Location:
    the hills
    :jkam

    Time well spent. Some is a bit dated but it covers the fundamentals of 2 stroke tuning/building very well.
    #5
  6. shovelstrokeed

    shovelstrokeed Long timer

    Joined:
    Jun 20, 2003
    Oddometer:
    5,700
    Location:
    6South Florida
    I read that when it first showed up. Lost my hard copy at least 5 moves ago. Just finished CH 1 and I’ll be in my bunk through the weekend. I’m gonna need some ice cream and some Oreos to get through the rest. I quit both smoking and drinking a couple of weeks ago. Reaching 77 starts taking some of the fun out but Gummy Bears are still OK. I may not be able to publish my notes.
    #6
  7. anotherguy

    anotherguy Long timer

    Joined:
    Jun 18, 2009
    Oddometer:
    13,893
    Location:
    the hills

    Both at once?! Good luck my friend. I have some 2 stroke tuning stuff in PDF when you're done with Jennings. Including Gordon Blair's Design and Simulation of two Stroke Engines @ 641 pages. Oughta keep yer brain occupied for a bit.
    #7
  8. shovelstrokeed

    shovelstrokeed Long timer

    Joined:
    Jun 20, 2003
    Oddometer:
    5,700
    Location:
    6South Florida
    Thanks! I won’t say it’s been easy, but no where as hard as it was 20 years ago. That lasted 5 years, this time it’s for life. Of course, no telling how long that will be.
    I have to watch my weight (diabetes), and stay out of bars. Not teetotal, by any means, but no more than two beers and no more than once a week. Again, edible seems to be the answer.
    #8
  9. Zuber

    Zuber Zoob Supporter

    Joined:
    Sep 28, 2004
    Oddometer:
    5,330
    Location:
    West of the West, Oregon
    The 'Two Stroke Tuners Handbook' is the reason I became an Engineer.
    #9