New Member Building Superchared Bicycles

Discussion in 'Introduce Yourself' started by supercharedcustoms, Feb 2, 2010.

  1. supercharedcustoms

    supercharedcustoms New Member

    New member here on this forum. Not new to building custom bikes cars trucks or anything else fast enough to get hurt in. My latest project is taking one of these cheap chinese motors and supercharging it. I will put up a thread of how i did this with pictures when it is done. Right now it is still in the works and I want to complete it and have pics and specs for everyone before I release how it is done. If your interested in having some killer hp out of one of these lil' motors stay tuned.

  2. give me vtec

    give me vtec Active Member

    oh I definitely will... :lurk5:
  3. Clotho

    Clotho Member

    2 words:

    No valves...
  4. supercharedcustoms

    supercharedcustoms New Member

    This project may be bigger than for just the DIY kinda guy. Yes, agreed there are no valves however under small amounts of boost (1-2psi) even with the intake and exhaust ports open at the same time while some fuel air mix may blow out the exhaust the compression and charge density will still show a net increase at TDC. Custom exhaust chambers must be built so that back pressure is enough for a system like this. Efficiency on this motor not so great... but power gains are worth it. A note for anyone thinking about trying this on their own.... This can not be done with out a good machine shop. And just adding on a "blower" with out modifying the cylinder, piston, con. rod, exhaust, intake, carb, ect. is not going work. ( it will work for a while with out doing all the modifying, but it will eventually blow up (quite literally) in short order.)
    Last edited: Feb 3, 2010
  5. Mountainman

    Mountainman Active Member

    pick an engine with a strong heart -- guts

    Iam just not sure that it's worth doing all of that
    with a HT engine anyway ??

    If I were willing to put all of that work and time into said project
    I would pick an engine with a strong heart -- guts

  6. Fabian

    Fabian Well-Known Member

    Hi supercharedcustoms

    Go for it - make it happen.
    There is no reason at all why one of these engines cannot be supercharged.

    Standard exhaust port timing will reduce the total supercharged air/fuel volume charge reaching the combustion chamber but it will still over charge compared to piston cycling.

    Reduced exhaust blowdown time may help contain supercharged mixture in the cylinder, but adding a power valve system like the Yamaha RZ 250 or Suzuki RGV 250 could achieve the goal of variable blowdown timing.

    Last edited: Feb 3, 2010
  7. Fabian

    Fabian Well-Known Member

    Better still, would be to machine a completely new cylinder and cylinder head and a modified bottom end.

    I've thought about the concept of using a double sleeve valve cylinder, where one sleeve is used for conventional porting and the second sleeve valve is either electronically, mechanically or hydraulically controlled to allow variable port timing.

    It's a big job, but if you've got access to a machine shop and the time to make it happen, an absolute gem of an engine could be produced.

  8. supercharedcustoms

    supercharedcustoms New Member

  9. supercharedcustoms

    supercharedcustoms New Member

    To the response about picking an engine with strong guts, normally I would agree 100% but strong guts also means more $ I am doing this as a low buck fun project to see how much power I can crank out of something tiny. I have the knowledge and access to the tools so if it isn't costing me much other than spare time... why not?
  10. supercharedcustoms

    supercharedcustoms New Member

    By the way I moved this discussion to Garage & Tech/Mech Help-detailed & specific tech talk section under "Wild in the Streets" Bottom of the main forum page. It is listed under Supercharged 2-stroke engine
  11. Fabian

    Fabian Well-Known Member

    I'll be following this thread with eager keenness.
    Don't let the idea evaporate.

    supercharedcustoms, make it happen.

    I want to see the finished engine in operation and if it works reliably and efficiently, i'll be placing a purchase order.

  12. JemmaUK

    JemmaUK Guest

    While I can see this working in principle I'm not sure this is a great idea with something with such variable build quality - have you seen what happens when a supercharged engine throws a rod?

    I saw a tractor-pull once where some bright spark had put 4 supercharged tractor engines inline on one chassis - the black smoke was impressive enough - the white smoke, and flying rod complete with coconut sized flying piston that imbedded itself into the earth by a good foot - was even more impressive (especially to the 5 year old girl it missed by inches)

    Having that between my legs at 30+mph is not something I wish to experience.

    I can see how this would work - Ettore Bugatti came up with something similar although in his case it was a chain driven double lobe rootes type on a 18cc engine - but I would trust his engineering and quality control much more than I would a CGE

    I personally see little point in this since with a little work a frame mount setup could easily be made to take the current crop of 4-5hp 2 stroke tuned engines from people such as DDM - twice the power on half the displacement - not to mention you'd get more power yet with a tuned pipe and my low percent nitro/petroil mix...

    By all means see if it can be done - but I would be very suspicious if this could be done safely with the current stock of CG engines - and if an engine of this configuration fails under load I for one would not want to be the person liable for supplying it... because if it throws a rod or a piston through the side or head the only bits between it and the outside world in general will be important parts of the riders anatomy... not to mention the resulting accident and the injuries that could cause...

    Jemma xx