I need the calculation to figure out cc's

[Big - D Racing]

I'm looking for the formula to figure out how many cc's a given bike is. Does anyone know it or know of a website thattells it.

[tprender]

There are to 2 formulas that are used to find the cc's. the one that I used when I measure an engine is V=3.14*r*r*h if you just measue in cm. If you measure in Inches take the answer and times it by 16.387 to change to cm. The r is ahlf the bore and h is the stroke.
For example if you take the new 450R, it is bore of 94 mm and stroke of 64.8 mm. 94 mm =9.4 cm and 64.8 mm =6.48 cm

V=3.14*4.7*4.7*6.48
V=449.469648cc's

There is another one but I don't use it.

[LS@GtThunder]

Originally posted by Big - D Racing
I'm looking for the formula to figure out how many cc's a given bike is. Does anyone know it or know of a website thattells it.

There are shorter easier versions but they boil down to:

((((Bore/2) x (Bore/2)) x 3.14159) x Stroke) / 1000

Example:

400EX
Bore 85mm
Stroke 70mm

Bore/2 = 42.5

42.5 x 42.5 = 1806.25

1806.25 x 3.14159 (pie) = 5674.4969

5674.4969 x 70 (stroke) = 397214.78

397214.78/1000 = 397.21478cc

LS

[chad502ex]

Originally posted by Big - D Racing
I'm looking for the formula to figure out how many cc's a given bike is. Does anyone know it or know of a website thattells it.

Hey Big,

my website has a nice cc calculator that all you have to do is plug in the #'s and hit "calculate".

http://mywebpages.comcast.net/chad502ex/calc_displacement.htm

Hope this helps.

Chad502EX.com

[RAD]

Pie r squared X stroke

[wilkin250r]

Everybody is right on the money. Cubic centimeters (cc's) is a volume measurement. Volume is surface area multiplied by depth. Surface area is calculated from your bore diameter, pi times radius squared, where radius is half your bore diamter. All numbers must be in centimeters, so a 94mm bore is 9.4 cm diameter, or 4.7 cm radius.

3.1415926536*(4.7^2) for surface area.

Your depth is given by your stroke, just convert mm to cm.

[nacs400ex]

Yikes. I am all confused when I get to this stuff. I guess if I look at it and plugged my own numbers in I would understand it. I will use Chads calculater :D

[tprender]

Maybe if you would have paid attention in math class it would be easy. All that it is is volume of a cyclinder.

[nacs400ex]

I got 80's in academic math last year(gr 10) this year I am in 11. So I think I pay attention a little bit. But I just dont know why I dont understand it. For one I would probably find it a little easier if I wrote it out insted of ^2.

[wilkin250r]

The most important is to make sure all your numbers are in centimeters and not millimeters.

[honda250xrider]

i always used bore * bore *stroke * .007854

[Big - D Racing]

Thanks everybody that was exactly what I was looking for.

[Mr.FDO]

bore x bore x stroke x .0007854 = cc's
example: 85 x 85 x 70 x .0007854 = 397.21 cc's