Calculations

[ryan12590]

hi guys
well tonight ive been pretty darn bored so i decided to find out some info on boring and stroking i found it is 4 times more effective to bore a cylnder than to increase the stroker length , for every 1mm you bore on a cylinder you add around 4.6cc +/- 0.5cc ( between 54mm and 59mm)
and for every 1 mm of stroke added you gain only 1.15cc +/- 0.5cc also i made a table of bore size and what cc youl get based on a standard lifan 125 54*54 engine

bore cc
54 123.67
54.5 125.97
55.0 127.29
55.5 130.90
56.0 133.00

i think these are right they might not be correct me if im completely wrong but i thought someone contemplating boreing the cylinder might like some figures on the power gains or cc anyway

 

[greenhuman]

It has been my experience that stroking makes a lot more HP than boring. 25% more HP with a stroker crank over a big bore to the same cc's.

 

[ryan12590]

really i didnt relise that well now that changes the situation i guess

 

[noidea]

Also affects power range of the engine. stroking = more torque than boring and boring will let the engine rev a little harder than boring.