I here 48 cc engines & 66cc engines?I thought they where all the same.
47cc bore & 38cc stroke?? what gives?
Fly
47cc bore & 38cc stroke?? what gives?
Fly
I know there not 80 cc engines BUT?
- Thread starter Flyman
- Start date
I'm afraid I don't know the bores and strokes of these engines.
But here's what I've been told about the 80cc/66cc thing. In Asia they calculate engine displacement by adding the volume of the combustion chamber to the volume of the cylinder. In the West, it's strictly the cylinder.
So an engine that is 80cc in Peking (Oh, all right.....Beijing.....) is 66 cc in America.
But that doesn't really explain why and engine that's supposed to be 50cc is actually 48 or 49cc. I'm sure that combustion chamber is more than 1 or 2cc in volume.
So this explanation doesn't really explain a whole lot. And I don't even know if it's the truth, for that matter.
Hope it helps
But here's what I've been told about the 80cc/66cc thing. In Asia they calculate engine displacement by adding the volume of the combustion chamber to the volume of the cylinder. In the West, it's strictly the cylinder.
So an engine that is 80cc in Peking (Oh, all right.....Beijing.....) is 66 cc in America.
But that doesn't really explain why and engine that's supposed to be 50cc is actually 48 or 49cc. I'm sure that combustion chamber is more than 1 or 2cc in volume.
So this explanation doesn't really explain a whole lot. And I don't even know if it's the truth, for that matter.
Hope it helps
This stuff is so funny to me.I,m just getting in to this hobby.I owned a
racing kart shop for sometime & raced karts my self.Now that was years
back, but I do have a back ground in two stroke engines.
But I still get confused reading all this forms.But this is what I THINK I
have come up with & if I,m wrong some one correct me.But it sounds as
though with all the companys in china, they can bore these thing out, larger
or smaller from one to another.I think the stoke is all the same, just the bores
can differ.Will one of you experts' please clear this up.Lord is this crazy stuff (WINK)
Fly
racing kart shop for sometime & raced karts my self.Now that was years
back, but I do have a back ground in two stroke engines.
But I still get confused reading all this forms.But this is what I THINK I
have come up with & if I,m wrong some one correct me.But it sounds as
though with all the companys in china, they can bore these thing out, larger
or smaller from one to another.I think the stoke is all the same, just the bores
can differ.Will one of you experts' please clear this up.Lord is this crazy stuff (WINK)
Fly
pistons are 40mm, 45mm & 47mm for the 49cc, 60cc & 66cc - cases for larger bores are also bored larger to allow a fit - cases also differ in head stud size between 6mm & 8mm - another diff in cases are the large diameter mains & small diameter mains - also big diff between tapered shafts throughout & non-tapered shafts - also wide woodruff keys & slots vs narrow of the same - next, is taller and shorter barrels with diff heights of ports for exact same bore & stroke, but diff thickness of gaskets & diff performance specs - and last is pistons marked '1' thru '4' to indicate oversize for greater compression characteristics
all the above is why I replace motors rather than re-build
all the above is why I replace motors rather than re-build
in their quest to make a bigger motor they forgot to move the transfer ports so the piston only opens 1/2 the port. looks like charlie was asleep in class that day.
