An oil-less engine with an integrated cylinder head is described. Oil-less engine allows manufacturers to build environmentally safer oil-free engines, with fewer engine parts and at reduced costs of manufacturing. In one embodiment, the present invention an internal combustion engine comprising a reciprocating cradle having pistons. The cradle is assembled with a circular disk that rotates. The rotation of the circular disk causes the pistons and the cradle to reciprocate and thereby causing a combustion with cylinder heads.

The invention relates to a method for reporting a corrosion problem on a motor vehicle considered new, said method having the following steps: a step of monitoring (E0) the operating stability; a step of determining (E1) a reference corrective factor (KREF) for each cylinder; a step of storing (E2) the reference corrective factor (KREF) determined for each cylinder; a step of monitoring (E3) the operation of the engine at said determined operating point (PF); a step of determining (E4) a new vehicle corrective factor (KNEF) for each cylinder; a step of computing (E5) the difference (DIF) between the stored reference corrective factor (KREF) and the new vehicle corrective factor (KNEF) for each cylinder; a reporting step (E6) indicating that the fuel injector tip of the cylinder is corroded.

A structural arrangement for an internal combustion engine and/or star shaped air compressor, without a crankshaft and connecting rods and with one or more surrounded pistons, being able to use any fuels in the case of the engine, liquid or gaseous including hydrogen and obtain high thermodynamic efficiency. The engine and/or air compressor has an arrangement that makes it possible to transmit linear movement into circular movement by means of a ring together with an eccentric and with a coupling structure, The structure joins the pistons to the ring, which can be polygonal in the case of the use of at least three pistons or welded in the case of one or two pistons.

An off-road vehicle includes a frame, a side-by-side seating area, a plurality of wheels, a prime mover assembly, and a drive train. The engine has three cylinders driving a transversely-extending crankshaft, with a left-most cylinder at least partially left of the longitudinal midplane and a right-most cylinder at least partially right of the longitudinal midplane. Neither the main drive shaft nor any other of the drive line components delivering torque extend under any of the plurality of cylinders of the engine. A majority of length of the main drive shaft is located on an opposite side of the longitudinal midplane as the engine centroid. The engine is tilted to define a receiving space over or under a portion of the engine, and at least part of the gear assembly is received in the receiving space, with a turbocharger over the gear assembly.