How many cc's do I have now?

M

MattXR250R

Member

Oct 21, 2002

7

0

• Oct 21, 2002

• #1

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

 

B

BigBore

Member

Jun 16, 1999

693

0

• Oct 21, 2002

• #2

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

 

Rich Rohrich

Moderator / BioHazard

LIFETIME SPONSOR

Jul 27, 1999

22,839

16,904

Chicago

• Oct 22, 2002

• #3

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

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

 

B

brandolph

Member

Oct 7, 2002

36

0

• Oct 22, 2002

• #4

What's ^??

 

B

biglou

• Oct 22, 2002

• #5

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

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

 

Z

Zenith

Member

Jan 11, 2001

483

0

• Oct 22, 2002

• #6

^ 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

r_rider28

~SPONSOR~

Feb 24, 2002

75

0

• Oct 22, 2002

• #7

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

 

B

brandolph

Member

Oct 7, 2002

36

0

• Oct 23, 2002

• #8

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

 

M

MattXR250R

Member

Oct 21, 2002

7

0

• Oct 24, 2002

• Thread starter
• #9

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

 

R

r_rider28

~SPONSOR~

Feb 24, 2002

75

0

• Oct 26, 2002

• #10

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

Click to expand...

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

 

G

Glitch

~SPONSOR~

Dec 3, 2001

631

0

• Oct 26, 2002

• #11

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