The present invention provides a four-stroke, piston-powered internal explosion (IE) engine for providing power output through a rotating crankshaft. The IE engine includes an engine block having power cylinders formed therein for receiving working pistons, bearing means for supporting the crankshaft, and a crankshaft supported within the bearing means having an output end extending outside of the engine block and a plurality of offset power cranks. The IE engine further includes connecting rods operably coupled to the power cranks and configured to transfer power from the working pistons to rotate the crankshaft, and working pistons that are received into the power cylinders and operably coupled to the power cranks. Each working piston has a head end positioned adjacent to a cylinder head to form a compression chamber and is configured to receive power from an explosion of a compressed volume of air/fuel mixture located within the compression chamber, and to transfer the received power to the connecting rods. The IE engine is further configured so that the compressed volume of air/fuel mixture is substantially constant, and a peak compression ratio is maintained, from an angular position of the rotating crankshaft of at least 20 degrees prior to a TDC position of a compression stroke, to an angular position of at least 20 degrees after the TDC position of a power stroke, and prior to detonation.