math help

[roadx]

ok if a bore is 2.579. inches that would make it 65.50659999999999 millimeters right???
and a stock bore for a 200x is 65.0 millimeters
so.... would that make it .50 over or ????
i think i know the anwser but..... ive been wrong before

[250sx]

well I'm no math wiz :D You can go to wiseco.com and look up their application chart which will answer your question.

[roadx]

hmmmm i cant get to the pdf files on wiseco, can anyone else?

[roadx]

ok a got the wiseco pdf file(from a uk site) and it showed
65.5 MM is .20 over
66.0 MM is .40 over
66.5 MM is .60 over
i must have missed something !!
where did i go wrong???? so.... is my calculations off up top??

[Fuzzy]

Ok your math is right. the stock bore and the stock piston size are two different things. The stock bore is 65.0 mm or 2.563". but the stock piston is 64.9mm to allow space for the rings. So the piston size is allways going to be smaller then the bore. Or you wouldnt be able to pound the piston in with a jackhammer. So by using these figures you can see where they get the .020 over and so on.

[ATCnut]

I think I see your confusion. The units for when you refere to " 20 over" is in thousands of an inch. The data from the wiseco pdf shows that each .5 mm over is 20 thousands of a inch over. So, from your original measurements of a bore that is 2.579 inches, or 65.5 mm, it is 20 thousands of a inch over, or .5 mm over.

I wish the whole world used the same measurement units, would make life easier.

[roadx]

thanks guys, i wasnt thinking right, it makes since the pistion would be smaller! and converting only makes things crazyier

[101987]

66.25 is 50 over