Optically improved engine for testing, particularly for measuring combustion parameters

The crankshaft (4) is connected to a slider (6) which is joined to the piston (8) by a strut (7). The piston is contained within a transparent cylinder (20) which is pressed against a cylinder head (11) by a pneumatic annular jack (17) from a lower motor frame (13). The cylinder head and base (12) slide on columns (14) and are controlled by a jack (15) fixed to the lower motor frame. A camera and mirror (10,9) take pictures through a transparent piston wall.