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View Full Version : How egzacly does .10, .20, .30,....... work?


Narly R
10-23-2003, 09:00 PM
Ok about how many cc's does an .10 equal, caus ei had my bike bored out .40 over how many cc gain will i see, and how much power diff will i see?:confused:
Guy400
10-24-2003, 05:26 AM
When boring you go in .010", .020", .030", etc. All things remaining the same you'll see virtually no horsepower gain by a simple bore job.

The calculation for finding displacement is: bore x bore x stroke x .7854 x number of cylinders. Remember, when doing this calculation convert all of your figures to metric to find CC's (don't tack on .040 inches to your piston that's measured in millimeters).
Narly R
10-24-2003, 11:10 AM
Ok mthanks man, I was just woundering cause nobody has ever really explained it to me. :)
H_W
10-24-2003, 01:57 PM
0.40 over is approximately 10 more cc's.
jasoncarr25
10-24-2003, 06:40 PM
if .40 over is 10cc's that makes my 440 1.60 over?
Narly R
10-24-2003, 11:21 PM
Sounds like it could be like that...:ermm: I should see some power increase shouldnt I?
H_W
10-25-2003, 07:33 AM
With a 440 you usually have to put in a new sleave. A 416 is bored 0.80 over and a 426 is bored 1.20 over.
Narly R
10-25-2003, 10:56 AM
Ya If you didnt re-sleever a 1.60 bore or if u bored a bike out that far it would just be too much.
hondafox440
10-25-2003, 12:36 PM
Originally posted by H_W
0.40 over is approximately 10 more cc's.

That all depends on the original bore size. .40 over on a 50 is not 10cc's, and .40 over on a ZX-12R is much more than 10cc's.
jasoncarr25
10-25-2003, 02:01 PM
that makes sense.
Narly R
10-25-2003, 07:00 PM
Ya, so if u use Guy's equation thing it will work for no matter what size motor?
H_W
10-25-2003, 07:04 PM
That makes sense. I know it would depend on the size of the motor, I was using a 400ex as an example.
hondafox440
10-25-2003, 10:39 PM
Originally posted by Narly R
Ya, so if u use Guy's equation thing it will work for no matter what size motor?

Yea, it should. All you need to do is use the volume of a cylinder formula - πr²h, which in engine terms is (π x bore)² x stroke.

In case it doesn't show up correctly, π = pi, which ≈ 3.14.
wgbanks
10-26-2003, 08:01 PM
This web site is a quick and easy way to figure your cc's


http://www.nightrider.com/biketech/calc_displacement.htm