A1 abstract an action reaction combustion engine comprising of one or more engines with one or more pistons having adequate mass being housed in mated cylinders and having two opposing heads also having valving plumbing fuel delivery and starting means and allowed to reciprocate on linear bearings delivering a workforce on each end of back and fourth stroke one force when the pistons compresses and stops and one force when fuel ignites or high pressure air pushes and drives the piston back producing four power events every one complete reciprocating cycle or revolution of the crank or other drive mechanism application_number US 201414254665 A description an action reaction free piston combustion engine composed of one or more said engines connected to a crank or other drive mechanism consisting of one or more pistons and cylinders said engines with three or more said pistons traveling together and being attached by rods and are allowed to reciprocate the two smaller said pistons on each end and the one large heavy said piston in the center are moveable and mated to their perspective said cylinders separated by two bulkheads the said rods and said pistons are supported by lineal bearings the said lineal bearings being.