What is the difference between boring and stroking a motor?

[sheemo3]

Can anybody help me out? Thanks

[boosted331]

bore is the diameter of the cylinders, stroke is the length the piston travels in the cylinder. Typically a motor with a longer stroke and a smaller bore won't rev as high as a big bore/small stroke motor, but will produce much more torque on the low end. On the flipside, a big bore, small stroke motor will rev like the dickens but not make much torque.

[93hybridaccord]

In order to bore a motor, you grind away at the cylinder wall. Not much, we are talking like thousandths of an inch. A stroked motor is when you enlarge the lobe on the crank. 2 ways to do this, either buy a larger crank or either you or a shop has to place a weld on the lobes then grind and sand it down til it's clean but a hair larger.

[S13GTR]

To make a long story short if you stroke you gain bottom end and loose revability, boring leaves you the same revability and gives improved powerband.