80cc engine?

Discussion in 'Motorized Bicycle General Discussion' started by Greg58, May 3, 2012.

  1. Greg58

    Greg58 Well-Known Member

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    #1 Greg58, May 3, 2012
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  2. Greg58

    Greg58 Well-Known Member

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    I have tried to link the full page but can't , but anyone cAn find it.
     
    #2 Greg58, May 3, 2012
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  3. Al.Fisherman

    Al.Fisherman New Member

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    #3 Al.Fisherman, May 3, 2012
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  4. maurtis

    maurtis New Member

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  5. 2door

    2door Moderator
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    They can 'say' all they want, and post photos (Photoshop?) but until someone physically measures the bore and stroke, I'm unconvinced. Displacement does not include the combustion chamber volumn which is where some sellers get the extra CCs and where the term "80cc" came from originally. To my knowledge there are no true Chinese 80cc engines available. I might be misinformed but I want proof before changing my opinion.

    Tom
     
  6. Greg58

    Greg58 Well-Known Member

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    Thanks for posting the link, I was trying to post from my iPod. It is hard enough for me on a computer! Anyway Tom what I was thinking about was the low end torque gain that might be possible, kinda like a NASCAR engine of358 ci. But has a 4-5/8 bore and shorter stroke.
     
  7. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Who will be the first guinea pig?
     
  8. Dirt Road Cowboy

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    That looks EXACTLY like the one I bought. Same cheesy decals and everything!




    .
     
  9. Greg58

    Greg58 Well-Known Member

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    Now that I got to my computer let me explain, in nascar engines the bore has gone up over the years and the stroke shortened. This has proven to increase the low end torque greatly. A 350 ci chevy small block has a bore of 4 inches, the current nationwide 358ci toyota engine has a bore of 4.470 inches. nationwide engines have about 200 less hp than sprint cup engines which specs. are hard to find.
     
    #9 Greg58, May 3, 2012
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  10. 2door

    2door Moderator
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    We're not arguing the effects of more cubic inches. We want proof that the engine advertised is actually what they claim it to be. I think all the old gear heads here will agree that "The only subsitute for cubic inches, is more cubic inches". What we have a problem with is the basic casting of the Chines 2 stroke engine as we all know them. To get an actual 80cc stuffed into it would require a larger bore, or a longer stroke and that would require a bigger cylinder or a crankshaft that is different from what every engine out there comes with.
    I've yet to see anyone successfully bore a chrome plated, aluminum cylinder or build a crank with a longer/shorter stroke. Changing the connecting rod length does not alter stroke. The stroke is dictated by the crankshaft throw and cylinder volume is only changed by boring to a larger diameter. Not an easy task with an HT (Happy Time, Chinese 2 stroke) engine. Advertising claims are one thing; real world measurements are another.

    Tom
     
  11. Greg58

    Greg58 Well-Known Member

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    I agree, Ron said that he has one of these so maybe he can tell us more about his, or maybe DRC has opened his up.
     
    #11 Greg58, May 3, 2012
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  12. Dirt Road Cowboy

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    I took off the top end of mine when I first got it to change the head studs and head gasket.

    The gasket that I put in was the standard 66cc one from SBP. It was not a larger bore. The piston in the photo looks considerably larger in diameter than a stock 66cc.

    It is possible that their scam is just taking a picture of a piston from some other 2 stroke engine and claiming it is theirs.




    .
     
    #12 Dirt Road Cowboy, May 3, 2012
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  13. Greg58

    Greg58 Well-Known Member

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    I was hoping for a new"toy" that we all could play with!
     
  14. multipaul

    multipaul New Member

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    It's definitly a fake. I englarged the picture and measured the 49cc piston's diameter on my monitor. We know that this piston is 40mm, So I've got a scale. Using the scale on the piston in the middle, I found its diameter is 45mm and the right one is 47mm.:eek:
    In Germany that "kind of selling" is fraud and forbidden.

    Multipaul
     
  15. DaveC

    DaveC Member

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    That's very odd, then. When Dodge first got back into NASCAR racing Petty Enterprizes had to get rid of over 200 engines that were overbored to NASCAR specs. The reason is Large bore, short stroke motors can be spun faster than a square bore/stroke set-up. I have a Pontiac 151 Iron Duke motor. In reality it's a Jeep version but no real difference except a stiffened block and their own head. It has a 4.00 inch bore with a 3 inch stroke. This is the same dimentions as the 60's Z28 motor that were famous for 8500 RPM blasts down a quarter mile. The Iron Duke won't spin like that due to sucky intake ports but they easily spin to 7000 RPM until they run out of air.

    I think what it is is Toyota has a bore spacing of 4.470 and not a bore of 4.470 or you would hear screaming from the other 3 manufacturers.
     
  16. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I sent the seller a message regarding this engine, I will report back with the results.
     
  17. Greg58

    Greg58 Well-Known Member

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    Let me first say sorry for going in the wrong direction with this thread, my intent was to find out if this was indeed a 80cc engine and if it were was there any noticeable differances from the 66cc engines. Most if not all that have replied know alot more about these engines than I. Maybe we wil find out more later but it is hard to understand why someone would advertise that if they did not believe it to be true, Greg.
     
  18. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Can you say "scammer"? Knew ya' could.

    I haven't heard back from him even though I sent him a very polite question..."If I buy one of these and find it to not be a full 80cc engine, can I return it for a full refund?
    Thanks!
    Joe"

    I got no response...
     
  19. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Sent a second message to them.... :)
     
  20. multipaul

    multipaul New Member

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    What I've written up there, it is too hard! Sorry for that.

    Inch, square inch and Kubikzentimeter (=cc) doesn't go together well.
    Better suggestion even for people with simple calculators:

    Displacement in cc = b x b x s x 12,87
    b: Bore in inch
    s: Stroke in inch
     

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