Yea...pretty lame question but I must know. The dealer is replacing my burnt Weisco with another one and going .01 over. (something like that)

Will this effect my quads power at all or just bump up the cc's a bit? What over-size is considered a big-bore?

Brian

 

Rest your mouse a while and we will figure this one out.

http://www.polarisindustries.com/pro...s&tipYear=2000

from page 4 of the parts manual we can see that the dimensions for the CC of a standard 400 is 83mm with a stroke of 70mm.

So the formula for C.C. is PI times the radius squared times the length of stroke.

3.1428 x (41.5 x 41.5) x 70 = 378.88 CC

If we increase the size of the bore .001 which is a common overbore our formula will look like this.

3.1428 x (41.627 x 41.627) x 70 = 381.210

This would only increase your CC by 2.33

 

Yes sir Thor! That's about "1/2 of a percent" increase! That's too much power for me now...LOL

 

Thor. Good caculations, but Wiseco piston oversizes are in .5mm increments, so Xplor has gone 1mm over size, as have I, not .001. His piston is now 84mm.

So 3.1428 x (42x42) x 70 = 388.07cc

A 10cc gain, a 2.7% cc gain.