Is this the formula for figuring displacement????
BORE x BORE x STROKE x .7854 x # of cyl.`s
If so my motor came out to 55.62.....
BORE x BORE x STROKE x .7854 x # of cyl.`s
If so my motor came out to 55.62.....
Real 80's?????
- Thread starter Bikeguy Joe
- Start date
Area = PI R Squared: measure the bore and divide by 2. multiply this number times itself or hit "X" squared on the calc if you have that function. Now multiply this number times PI. PI = 3.1417. This will give you the cross-sectional area of the cylinder.
Cylinder volume = Area X Stroke. This will give you the volume in cubic inches. then go here and convert to CC's
Online volume conversion
Jim
Ive Always Been Told On Bikes( Motor Cycles ) That A 125 Is Actually A 124 And 250-249 And Soo On...i Bought My Kit From Livefastmotors And He Clearly States On His Sight That None Of These (china Motors) Are Even Close To 80;s... He Says Theyre 70's... This Is Why I Purchased From Him , I Had A Feeling That They Were Over Rated On Cc;s And This Guy Seem To Have Done His Homework ( Considering He Is Selling Them)... So Yeah Without Meassuring Id Say Mine Is A 69/70..
Im Not Digg'n' The False Advertisement Of The''80cc''.what A Bummer... So Lets Call Em 69 Ers....or 81's haha
Im Not Digg'n' The False Advertisement Of The''80cc''.what A Bummer... So Lets Call Em 69 Ers....or 81's hahaRe: Put up or shut up....
The diameter of the so called 80cc is 46.7mm (measured with a digital caliper acurate to 1/100 of a millimeter). http://pack127.net/images/cylinderdiameter.jpg
The depth of the cylinder with the piston at full depth is 40.00mm. http://pack127.net/images/cylinderdepth.jpg
Sorry the photos are a little blurry... Anyway...
The calculation is as follows:
Diameter = 46.7mm
Depth = 40.00mm
Radius = Diameter / 2
Radius = 46.7 / 2
Radius = 23.35
Area of a circle (cylinder) = Pi * Radius * Radius
Area of the cylinder = 3.141593 * 23.35 * 23.35
Area of the cylinder = 1712.867 square mm
Volume of a cylinder = Area of cylinder * Depth
Volume of the cylinder = 1712.867 * 40
Volume of the cylinder = 68514.68 cubic mm
1 cubic millimeter = 0.001 cubic centimeters
68514.68 cubic mm = 68.51468 cubic cm (or 69cc)
So there you have it. The so called advertised 80 cc engine is actually a 69cc engine.
Well here is the real deal.
The diameter of the so called 80cc is 46.7mm (measured with a digital caliper acurate to 1/100 of a millimeter). http://pack127.net/images/cylinderdiameter.jpg
The depth of the cylinder with the piston at full depth is 40.00mm. http://pack127.net/images/cylinderdepth.jpg
Sorry the photos are a little blurry... Anyway...
The calculation is as follows:
Diameter = 46.7mm
Depth = 40.00mm
Radius = Diameter / 2
Radius = 46.7 / 2
Radius = 23.35
Area of a circle (cylinder) = Pi * Radius * Radius
Area of the cylinder = 3.141593 * 23.35 * 23.35
Area of the cylinder = 1712.867 square mm
Volume of a cylinder = Area of cylinder * Depth
Volume of the cylinder = 1712.867 * 40
Volume of the cylinder = 68514.68 cubic mm
1 cubic millimeter = 0.001 cubic centimeters
68514.68 cubic mm = 68.51468 cubic cm (or 69cc)
So there you have it. The so called advertised 80 cc engine is actually a 69cc engine.
In my opinion, wouldn't it be worth knowing how Chinese come
up with 80cc displacements. Displacements in China ranges from
from 48cc up to an interesting 80cc, in 10cc increments. It
makes
since to me.
up with 80cc displacements. Displacements in China ranges from
from 48cc up to an interesting 80cc, in 10cc increments. It
makessince to me.
Joe not to get away from bore and stroke,But for a number of years i had a chinese cook.I asked her if she knew how to make rice krispie treats,she nooded her head to say yes,so off i go.When i got home that night,low and behold on the counter a cookie sheet with a towel over it.I was so proud of har gong jue.I removed the towel to discover FROOT LOOP TREATS,we were out rice krispies.