RECIPROCATING PISTONS INTERNAL COMBUSTION ENGINE

1. Reciprocating piston internal combustion engine, the cylinder linings (28) of which have a cylinder bore diameter of 400 mm and more and whose pistons are articulated on a crankshaft (5) by means of connecting rods, the crankshaft being mounted in a machine frame (1) cast in one piece, and carried by bearing caps (6) fixed from below, wherein the bearing caps (6) have through-holes (20) for passing tie rods (21) through to secure them to the machine frame (1) and wherein the cylinder linings (28) are fixed on the machine frame (1) by tie rods (30) carrying nuts (36) on threaded shanks (34) at least on their upper ends and penetrating, by means of through-holes (31), cylinder heads (29) fixed on top, characterised by the combination of the following features : a) the one-piece machine frame (1) is cast from simple grey cast iron (GG25 or GG20) b) for securing the bearing caps (6) the one-piece machine frame (1) has through-holes (19) in alignment with their through-holes (20) for passing through correspondingly long tie rods (21) which completely penetrate the through-holes (19, 20) not having any thread, and at each end respectively carry a nut (24, 25) on a threaded shank (22, 23), one of which nuts (24) is supported on a corresponding contact surface (26) on the upper side of the machine frame (1), and the other of which (25) is supported on the lower side (27) of a bearing cap (6), c) the one-piece machine frame (1) has an intermediate partition (3) approximately on a level with its neutral bending zone, on which the tie rods (30) leading to a cylinder head (29) are fixed with their lower ends, d) all the tie rods (21; 30) extend beyond the nuts (24; 36) at least with their threaded shanks (22; 34) arranged at the upper ends, and with this projecting part form a supporting upstand for fixing and retaining a tie rod clamping- or nut-loosening device.