A two-stroke, opposed-piston engine includes a cylinder with an inlet piston controlled inlet port and an exhaust piston controlled exhaust port, the cylinder defining a combustion chamber with the inlet piston and the exhaust piston, a charge air channel in flow communication with the inlet port, a conduit extending directly from the combustion chamber to the charge air channel, and a valve arranged to selectively open and close flow communication through the conduit.

Aspects of the present disclosure are directed to an internal combustion engine having a valve actuation device and at least one first exhaust valve and one second exhaust valve per cylinder. The first and second exhaust valves may be actuated together in at least one operating area of the internal combustion engine, via an exhaust valve bridge and a first valve lifter, by a first cam lobe of a first exhaust cam arranged on a camshaft. The camshaft having a second exhaust cam with at least one additional cam lobe and at least one second cam lobe A transmission device being arranged in the functional path between the second exhaust cam and the second exhaust valve, the transmission device allowing an idle stroke to be activated or deactivated. The first exhaust cam and the second exhaust cam are configured and arranged to be rotatable relative to one another.

A method of determining a condition of a component (e.g., valves) of an engine having a manifold air pressure sensor during a cold test includes providing pressurized air to an intake of the engine. The method includes rotating a crankshaft of the engine. The method includes measuring pressures with the manifold air pressure sensor as a function of crankshaft rotational position. The method includes comparing the pressures with a predetermined baseline. The method includes indicating a condition of the component based on the comparison of the pressures with the baseline.

The present invention concerns an air motor comprising a piston and a housing, the piston being received in the housing and dividing the housing into two primary chambers of variable volume. Said motor comprises a first direct supply valve for supplying a first primary chamber of the two primary chambers and a second direct supply valve for supplying the other primary chamber, said two valves each being movable relative to at least one respective seat. The first valve and the second valve are mounted on a same stem movable relative to the housing in a direction parallel to the direction of movement of the piston, and the stem is configured to be moved between a first position and a second position by moving means activated by the piston.

Aspects of the present disclosure are directed to an internal combustion engine having a valve actuation device and at least one first exhaust valve and one second exhaust valve per cylinder. The first and second exhaust valves may be actuated together in at least one operating area of the internal combustion engine, via an exhaust valve bridge and a first valve lifter, by a first cam lobe of a first exhaust cam arranged on a camshaft. The camshaft having a second exhaust cam with at least one additional cam lobe and at least one second cam lobe A transmission device being arranged in the functional path between the second exhaust cam and the second exhaust valve, the transmission device allowing an idle stroke to be activated or deactivated. The first exhaust cam and the second exhaust cam are configured and arranged to be rotatable relative to one another.

A cylinder head comprising a single intake valve and at least two exhaust valves per cylinder. The two or more exhaust valves may provide additional curtain area and total cross sectional area for the exhaust flow and better performance for engines equipped with a cylinder head in accordance with the present disclosure.

An internal combustion engine includes a cylinder head including an intake port, an exhaust port, a water jacket, an intake valve, an exhaust valve, an intake valve seat, and an exhaust valve seat. The water jacket is positioned between the intake port and the exhaust port. The intake valve includes an intake valve head, and the exhaust valve includes an exhaust valve head. The intake valve contacts an intake valve seat surface of the intake valve seat. The exhaust valve head contacts an exhaust valve seat surface of the exhaust valve seat. The shortest distance between the water jacket and the intake valve seat surface is shorter than the shortest distance between the water jacket and the exhaust valve seat surface.

Embodiments of a compact pressure swing reformer are disclosed. Certain embodiments have a construction comprising multiple rotating reformer beds, high temperature rotary valves at the bed ends, and E-seals to seal the beds to the valves. Several possible designs for introducing reactants into the beds also are disclosed. The multiple reformer beds are configured to provide for pressure equalization and steam push. The compact pressure swing reformer is suitable for use in fuel cell vehicle applications.

An air motor (10) that receives compressed air in order to be driven. The air motor (10) includes a valve assembly (11) with a base (12) of a unitary construction. The base (12) has opposite side faces (13) to which there is sealingly attached caps (14) that in cooperation with flexible diaphragms (15) provide working chambers (15, 16).