Will A 66cc Fit?

Discussion in 'Frame Mounted Engines' started by spokedjoke, Apr 9, 2012.

  1. spokedjoke

    spokedjoke Member

    So my buddy said if i can get a 66 or 48cc HT on this bike he will buy it off me and i get a riding buddy too:clap: Its a 24 inch magna dagger. steel frame. It measures 13" from the bottom bracket to the top tube. Pretty tight but my buddy is only 5' 5" LOL so if we can make it work he will be HAPPY! Would an offset intake be enough? any help would be great!

    Attached Files:

  2. Al.Fisherman

    Al.Fisherman Active Member

    I doubt it, if it does it would be a cramped fit. The engine has to be high enough in the frame for a 75 degree angle in the "V". Here are some pictures that might help you in your decision. 11" needed for the stock carburetor set up, due to cable.
    You may be able to get away with a frame like yours is you use a "Z" intake manifold. But I doubt it. $7.00 + shipping
    [​IMG] [​IMG]

    To get it lower, you can do away with the OEM rear mount.

    Last edited: Apr 9, 2012
  3. spokedjoke

    spokedjoke Member

    Ya that's what i was afraid of. I've only got 10" maybe 10 1/4". I've searched the forum for small V frame 24" wheel MTB style bikes for ideas but couldn't find any. Also, the diagram states 4.5" between pedals, however its pointed at the bottom bracket.. is that indeed the minimum BB width or from inside crank arm to inside crank arm ?
  4. Al.Fisherman

    Al.Fisherman Active Member

    I would think it's from (inside to inside) crank arm to crank arm, to clear the engine while peddling. Of course you could have a pull starter, but it would make it hard on the clutch starting from a dead stop. You'd have to push off with your feet.

    If you only have 10", I feel that doing away with the rear mount, and buying a "Z" intake, you just might fit it. But it sure will be close. I''ll take some more measurements.

    More pictures......
    http://s982.photobucket.com/albums/ae309/Ron-Becker/Engine Mounting/
    Last edited: Apr 9, 2012
  5. motorpsycho

    motorpsycho Active Member

    heck, here's my 20" "schwinn" with a 49 c.c. 2 stroke mounted on it.
    the frame is stock, and has not been modified for the engine to fit.
    the trick is the lack of an intake manifold....look close.
    this is an older style 49 cc that came with the carb bolted right to the cylinder.
    as long as you have the right degree of V in the frame, you can make an engine fit.
    don't say it won't fit until you actually set an engine in the frame. there's a little room to play.
    oh yeah, i ride mine like a motorcycle, and i never peddle to take off from a dead stop. I use the clutch like on a motorcycle....been doing it that way for 4 years now, and it still has it;s original clutch pads and original clutch adjustment from when i built it.
    granted, i don't ride it every day either.
    Last edited: Apr 9, 2012
  6. Al.Fisherman

    Al.Fisherman Active Member

    Engine width....
    I feel that 4.5" wouldn't clear, and you will have to bend both cranks a little, not much tho. If in fact you don't have close to 5".
    How to lower the engine 3/4" in the frame.

    motorpsycho......Nice looking bike. With your frame the front bar is curved, and gives you a little more room to work with. But I agree, you really need to mount the engine to really see what you have.
    Last edited: Apr 9, 2012
  7. Robot

    Robot New Member


    Here's a pic of an old project that I've set aside this shows the engine mounts cut the engine welded in place 26'' beach bike it will work this way but weld only one side of the engine case if you get this far I've got the engine on this frame damaged it and not I'm due to remove it entirely due it's welded both sides of the case my mistake on this project will attempt rebuilding later on..

    Attached Files:

  8. Robot

    Robot New Member

    not bad
  9. PuddleJumper

    PuddleJumper New Member

    I've built two

    I've built two 14.5 frame motor bikes First was a GT 26" but the frame was 14.5 " high. I mounted it. But had to find a short plug and a short carb breather. I had alot of fun with it and was fast. I built this one. and had to do some fab to make it fit. They would not let me post pic
    Last edited: May 6, 2015