Abstract: An internal combustion engine having a piston is disclosed. The piston has a circular flat piston heat portion extending normal to the piston axis and opposed depressions opposite the combustion chamber intake and exhaust openings, respectively. The circular flat piston head portion includes a beveled rim with a radiused profile, the piston head having a circular edge and the cylinder head has a circular circumferential edge which matches the circular edge of the piston to define a uniform quench area upon the compression stroke of the piston.