displacement question

[EXtremeRider]

wat displacemet would going fromm a 66mm to a 68mm piston make my displacement??

 

[CHutzell]

207.0 cubic centimeters

 

[EXtremeRider]

wat would the bore dimensions be? .078

 

[EXtremeRider]

i did the math and got thht i would get 225cc

 

[foolish913]

if i remember right a 74mm piston is a 240cc so a 68mm piston wouldnt be 225cc

 

[EXtremeRider]

im pretty sure tht a .240 runs a 72mm piston... so wat u said shoouldnt work with a 74mm

 

[foolish913]

your right about the 72mm on the 240 but think about it if the stock is 66mm an the 240 is 72 you only increase the size of the bore by 1/3 by going to 68mm so how would the cc go up more than half

 

[245stroker]

72mm piston is only 232cc

 

[foolish913]

72mm piston is only 232cc

im assuming the jug on a 240 is taller than the stock jug then?
there has to be something im not understanding:-/

 

[370]

the 240 kit is only 232cc's it works like other big bores.. 310 hondas and tecates are actually 295cc.. but on the last bore they are a 309cc.. so they call it a 310.

 

[370]

72mm bore with a stock crank is a 232 like said above.. 72mm bore with a 3mm crank is a 244cc

68mm bore and stock crank is 207cc

 

[foolish913]

thanks 370 that makes more sense now i understand what your saying

 

[370]

and why bore all the way out to a 68mm anyway? if you have a std bore (66mm) bore right now.. why bore is .080 to a 68mm anyway? you have wasted all of your bores... and when theat cylinder is out fo round or tapered badly guess what NEW SLEEVE!!!!!!

 

[EXtremeRider]

wait a minute i did the equation for displacement and i get 225?? {pie divided by 4 x bore x stroke x # of cylinders}...and wat size bore is the one before .40 over?

 

[Blasterdude27]

Interactive Engine Displacement Calculator

 

[370]

bore dia X bore dia X stroke X .7854 (.7854 is one forth of pie)

and you'll get exactly what we've been saying..

68mm X 68mm X 57mm X .7854 = 207006 cubic milometers then take that answer divided by 1000 to get cubic centimeters and you get 207.00 cc