waiting on my engine

Discussion in 'Motorized Bicycle General Discussion' started by mr.WFO, Aug 16, 2010.

  1. mr.WFO

    mr.WFO New Member

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    having trouble focusing on actual D'ing the W...

    so before it gets here & disappoints;
    what can you tell me about the engine itself?

    i ordered the '10 epa'd grubee 66cc...slant head.
    can the head be reversed to ease plug maintenance?
    can the jug be reversed to ease carb access?

    why do they bill it as a 66cc/80cc?

    i've got a pipe almost finished, but still need to flip my bars & fix a fender...

    how many of y'all get harassed by the police?
    I know some towns are ok with bikes under 50cc, pasadena, TX is not one of them.
    however, since i'm riding it to school...they can kiss my ass...

    anyone built a happy time v-twin?
    twin engine bike anyone?
     
  2. mr.WFO

    mr.WFO New Member

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    whats the consensus on the available expansion chambers?
     
  3. bairdco

    bairdco a guy who makes cool bikes

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    grubee's are good engines, usually. i've built 6 bikes with them and i like 'em. haven't had the 2010 model yet, though.

    the head can go on either way. there's no performance increase, it's basically designed for clearance.

    the barrel can be reversed, but there's some work involved. check my thread on it here: http://motorbicycling.com/f38/backwards-engine-experiment-1939-colson-13458.html

    in america, it's a 66cc, in china, they measure funny, so it's an 80. check the Grubee website (ads on the left of the screen) and they explain it.

    acme labs is working on a V twin. there's a thread here somewhere, just use the search.

    not from texas, so couldn't tell you about the laws there.

    i've never used an expansion chamber, but sick bike parts has one, and people seem to like them a lot.

    welcome to the forum...
     
  4. Nougat

    Nougat New Member

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    More info about the 66/80 split measurement --

    US measurement is bore x stroke, the end. East Asia measurement is bore x stroke plus the volume of space inside the head when the piston is at TDC.
     
  5. GearNut

    GearNut Active Member

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    Welcome to the forum!
     
  6. Goat Herder

    Goat Herder Gutter Rider

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    Welcome to the forum Mr.WFO!
     
  7. mr.WFO

    mr.WFO New Member

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    thanks for the info. & the welcome
     
  8. poo poo pipe

    poo poo pipe New Member

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    I got a grubee also like yours last week from king motors bikes,Was impressed on the better casting and finishing on the cases ,some others from diffrent places look rough, got it mounted but need to finalize the cable running and build a tank.
     
  9. mr.WFO

    mr.WFO New Member

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    bairdco, awesome writeup on the reversed jug.

    i was wondering if anyone has blueprint specs for these motors.

    & reading thru 2 stroke performance tuning by graham bell i found this:

    In an effort to minimise cylinder and piston distortion, some manufacturers have
    chosen to use an offset squish type combustion chamber (FIGURE 2.2). The exhaust
    side of a two-stroke cylinder and piston is always the hottest, even though cooling air
    flow is much better here than on the back (inlet side) of the engine. There are several
    reasons for this, all associated with the passage of very hot (630°C) exhaust gas
    through the exhaust port. The escaping gas heats the exhaust port and cylinder wall as
    well as the side of the piston. This can cause the piston to expand abnormally and in
    some circumstances to seize. To take care of this possibility, the manufacturer may
    choose to increase piston to cylinder clearance, but this may not be desirable as extra
    clearance can increase leakage past the rings and usually results in high piston wear. A
    safer step is to move the combustion chamber to the rear of the head. If this is done,
    the front of the piston crown is shielded from the combustion flame by the squish
    surface. Then, when the front of the piston is heated during the exhaust stroke, it will
    not expand so far due to its being initially much cooler.

    did you snap a pic of the inside of the head? i'm getting curious to what a blueprinted/tuned happy time will put out.
     
  10. mr.WFO

    mr.WFO New Member

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    uh-oh.

    methinks i'm gonna build a supercharger out of a smog pump.
    the sickness has begun.
     
  11. BarelyAWake

    BarelyAWake New Member

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    Then you may find these of interest;

    JE Performance Electronic Ignition and Supercharging

    GoKartGuru.com Blog Basic Principles in SuperCharging: A Go Kart With More Bolt On Power

    GoKartGuru.com Blog Getting More Umph Out of Your SuperCharger Set Up

    Some examples;

    Honda CD50 engine in modified Fantic Caballero frame & the Aisin AMR300.
    [​IMG]

    Engelbert Sczygiol designed supercharger for a 50cc two-stroke (1965)
    [​IMG]
    Images from: the bikes

    from: Supercharging small engines


    Keep us informed if you decide to take that plunge into madness :D

    brnot
     
    #11 BarelyAWake, Aug 19, 2010
    Last edited: Aug 19, 2010
  12. BarelyAWake

    BarelyAWake New Member

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    ...however I would like to point out that given some of the results of increasing a Chinese 2 stroke's compression - you may wish to consider a different engine, or at least upgrading all of the bearings, the connecting rod & wristpin as well as the head's fasteners... foureasy is quite familiar w/this ;)
     
  13. mr.WFO

    mr.WFO New Member

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    engine is in!
     
  14. mr.WFO

    mr.WFO New Member

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    thanks, vrry interesting stuff.
    this kit is retarded. it would be easier to weld a weed whacker engine to an aluminum bmx frame...with air conditioning.

    absolutely nothing 'fits'... onto my second grinding wheel.
     
  15. Goat Herder

    Goat Herder Gutter Rider

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