How many cc's do I have now?

[MattXR250R]

I have a 91 XR250R that has been bored .05inches over,anyone know how many cc's I now have?Its 249 stock, Thanks,Matt

 

[BigBore]

Not certain, just a ballpark figure.......something like 255cc.

 

[Rich Rohrich]

With Bore and Stroke measurements in mm you can use the formula

Pi * ( (Bore /2) ^ 2) * Stroke / 1000

 

[brandolph]

What's ^??

 

[biglou]

I think it says "Pies R Square". ;)

Bore divided by two, then squared then times pi. Divide that by the stroke divided by 1000.

 

[Zenith]

^ means "to the power of"s. Formula is (PI * r² * h) / 1000 ... Or
(PI * (Bore / 2)² * Stroke) / 1000


Oops, beat me to it there Lou, I was typing to slow :confused: ...

 

[r_rider28]

254.243cc's if you want to calculate it down to a gnat hair.

 

[brandolph]

Thanks.
Couldn't find the "^" button on my calkelatur.

 

[MattXR250R]

Thanks alot guys for all the help,Now atleast I know around where I am,Thanks again,Matt

 

[r_rider28]

Originally posted by r_rider28
254.243cc's if you want to calculate it down to a gnat hair.

Correction, I figured this at .03 instead of .05. Your correct displacement is 257.771 cc's

 

[Glitch]

Wow, thats a pretty cool formula, my CR125 is actually a CR129.417.