With
the extra bore capacity comes a need for extra fuel
to fill the cylinder. When the bore is increased and
the stroke distance remains standard there is a need
for a greater accuracy of camshaft because of the
effectively smaller window for the air fuel mixture
to enter the combustion chamber. This is especially
true, as other engine modifications will make the
engine rev higher.
Strictly
speaking it is best when increasing the bore size
to also proportionally increase the stroke length
of the piston. However this an expensive process as
it requires a new crank, new piston rods and an extension
plate on the block, with internal liners. Shown in
photo. Therefore it is generally only the bore diameter
that is increased. |