Internal-combustion engine

FIG. 1 is a first perspective view of an internal-combustion engine, showing our new design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a third perspective view thereof;

FIG. 4 is a fourth perspective view thereof;

FIG. 5 is a front elevation view thereof;

FIG. 6 is a rear elevation view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof;

FIG. 9 is a right side elevation view thereof; and,

FIG. 10 is a left side elevation view thereof.

The broken lines shown in the drawings illustrate portions of the internal-combustion engine that form no part of the claimed design.