how many cc is 0.40 over

 

Just do the math...

A stock 400EX bore is 85.0mm x 70.0mm. That's 8.5cm x 7.0cm.

So then,

pi * (8.5/2) squared * 7 = 397.20 cc

.40 over is,

pi * (8.54/2) squared * 7 = 400.95 cc

So, by boring it .40 over, you only gain about 3 cc.

 

You're missing a zero. .4 is four tenths of an inch, nearly half of an inch.

.040" is 40 thousandths and would apply to your desire to bore larger. Could be expressed as .04...4 hundreths as well.

 

Hrmmmm... Ok. That change things a bit. The calculations would look like this then:

.040" = about .1016 cm

pi * (8.6016/2) squared * 7 = 406.76

Which comes out to about a 9cc gain.

 

so then 0.80 over is a 416 on a 400ex?

 

Don’t forget about the conversion of standard to metric. There is 25.4mm per inch so (0.04 inches) in metric is 0.04*25.4=1.016mm. Add this number to the bore then calculate for displacement.

 

JUST GET A SPARKS 13:1 92MM PISTON AND BE HAPPY .....SPLIT THE CASE HAVE THEM BORED OUT GET A CARILLO ROD HAVE IT TRUED AND WELDED LIGHTN THE FLY WHEEL , GET BIG SLEEVE, RUN A DUCATI CARB WITH A ALCOHOL KIT AND HAVE A BEAST AT LEAST I WHOOP *** WITH IT

EDIT: sorry for the caps