The converting of linear motion into rotational energy when using the cylinders and pistons of an internal combustion engine without the use of a crankshaft.The replacement with dual high lead cam-screws and dual cam-followers allows for the efficient use of a complete combustion stroke without the resistance from the crankshaft at top dead center, and a greatly reduced resistance for the return stroke as there is no crankshaft turning resistance at the outer limit of the piston stroke.