With a inside measuring micrometer
The bore of a cylinder describes is measurement, in millimeters or inches, of the inside diameter of the cylinder. The diameter is the width across.
BORE
Take off a cylinder head and measure the diameter of the bore.
This is the diameter of the cylinder hole in the engine block for the pistons.
this is the diameter of the cylinder hole in the engine block for the piston
Generally the nominal diameter of cylinder bore is kept little smaller at cylinder head than at the bottom. The engine head will be generally heat and it tends to expand for these high temperatures. To prevent the bore diameter at head to exceed diameter at bottom,piston engine bore is ground with a slight choke.
Inside micrometer
If you have a physical cylinder to measure, measure the "width" of the circle that is the cross section of the cylinder. That is the diameter, Half the diameter is the radius.
Bore slugging is done by taking a lead cylinder(slightly larger in diameter than bore) and pounding it through the bore. Once it's through, you mic it with a caliper. This gives the bore's exact diameter.
You should notice a couple of things on purchasing an hydraulic cylinder, Bore Diameter: The diameter of the cylinder bore. Maximum operating pressure: The lowest working pressure is referred to as max. Operating pressure. Rod Diameter: Piston Diameter Type of Cylinder: Types of cylinder are ram cylinder, tie-rod cylinder and welded cylinder. Stroke: The travel distance of a cylinder is referred as stroke.
Bore is the diameter of the piston/cylinder, stroke is the distance the piston can travel between its highest position and its lowest position in the cylinder.
Enlarging the cylinder bore will increase cc's in a 2 stroke and ci's ina 4 stroke.....