An internal combustion engine includes a hollow cylinder, a piston within the hollow cylinder, and a cylinder head. A base valve assembly at a base of the hollow cylinder permits or restricts fluid flow from an intake manifold into a sub-chamber below the piston. The piston includes at least one intake port connecting a combustion chamber above the piston with the sub-chamber, and a transfer valve that opens and closes the at least one intake port. When the transfer valve opens the at least one intake port, fluid is permitted to flow from the sub-chamber to the combustion chamber. The internal combustion engine operates according to a four-stroke piston cycle, wherein multiple intake stages are provided. The intake stages may include intake of air into the sub-chamber during a compression stroke, transfer of air from the sub-chamber to the combustion chamber during a power stroke, intake of air-fuel mixture into the sub-chamber during an exhaust stroke, and transfer of air-fuel mixture from the sub-chamber to the combustion chamber during an intake stroke.

A cam follower is provided. The cam follower includes a polycrystalline diamond element, including an engagement surface. The engagement surface of the polycrystalline diamond element is positioned on the cam follower for sliding engagement with an opposing engagement surface of a cam. The cam includes at least some of a diamond reactive material.

A valve system/method suitable for an internal combustion engine (ICE), compressor pump, vacuum pump, and/or reciprocating mechanical device is disclosed. The system/method is optimized for construction of a four-stroke ICE. The rudimentary system incorporates an intake engine block cover (IEC) and exhaust engine block cover (EEC) that enclose an intake rotary valve disc (IVD) and exhaust rotary valve disc (EVD) that control intake/exhaust flow through a respective intake rotary valve port (IVP) and an exhaust rotary valve port (EVP) into and out of a combustion cylinder that provides power to a piston and crankshaft. An intake multi-staged valve (IMV) and exhaust multi-staged valve (EMV) provide intake and exhaust flow control for the IVD/IVP and EVD/EVP. An enhanced system may include a variety of intake/exhaust port seals (IPS/EPS), forced induction/discharge (FIN), centrifugal advance (CAD), and/or cooling channel spool (ICS/ECS).

Apparatus for controlling valve timing in an internal combustion engine locates a first valve port in a first side of the engine cylinder and a second valve port in a second side of the engine cylinder. A first rotating valve disc and a second rotating valve disc are respectively disposed next to the first and second valve port. Each rotating valve disc includes a valve port. Each disc rotates in synchronism with the crankshaft to align its' port with the respective first and second valve ports. A variety of intake devices coupled to the first rotating valve disc control intake air flow into the engine cylinder, and a variety of exhaust devices coupled to the second rotating valve disc control exhaust gas flow from the engine cylinder.

An internal combustion engine includes a hollow cylinder, a piston within the hollow cylinder, and a cylinder head. A base valve assembly at a base of the hollow cylinder permits or restricts fluid flow from an intake manifold into a sub-chamber below the piston. The piston includes at least one intake port connecting a combustion chamber above the piston with the sub-chamber, and a transfer valve that opens and closes the at least one intake port. When the transfer valve opens the at least one intake port, fluid is permitted to flow from the sub-chamber to the combustion chamber. The internal combustion engine operates according to a four-stroke piston cycle, wherein multiple intake stages are provided. The intake stages may include intake of air into the sub-chamber during a compression stroke, transfer of air from the sub-chamber to the combustion chamber during a power stroke, intake of air-fuel mixture into the sub-chamber during an exhaust stroke, and transfer of air-fuel mixture from the sub-chamber to the combustion chamber during an intake stroke.

A cam follower is provided. The cam follower includes a polycrystalline diamond element, including an engagement surface. The engagement surface of the polycrystalline diamond element is positioned on the cam follower for sliding engagement with an opposing engagement surface of a cam. The cam includes at least some of a diamond reactive material.

The disclosure includes manufacturing a semimanufactured cylinder head (3) having a shielding curtain portion (16g) and spraying metal powder (P) onto an annular valve seat portion (16f) using a cold spray method to form a valve seat film (16b). The shielding curtain portion (16g) projects in an annular shape from an annular edge portion of an opening portion (16a) of an intake port (16) or an opening portion (17a) of an exhaust port (17) toward the center (C) of the port. The annular valve seat portion (16f) is located on an outer side of the port than the shielding curtain portion (16g).

A poppet valve includes: a valve body comprising a valve stem body, a valve head body with a valve combustion face, and a valve fillet body interconnecting the valve stem body and the valve head body. The valve fillet body surface has an increased thermal resistance compared to the valve combustion face.

A valve train of an internal combustion engine may include a camshaft, first and second cams, a rocker arm assembly having a displacement bolt, which may be adjustable between at least first and second positions in the axial direction and on which at least one cam roller, may be mounted in an axially fixed and rotatable manner, wherein the displacement bolt may be mounted in associated bearing lugs of the rocker arm assembly, a guide contour arranged on the camshaft and having first and second guide tracks, a switching pin, which may be arranged in the displacement bolt and which may optionally engage with the first or second guide track to adjust the displacement bolt between the first and second positions. In the first and second positions, the cam roller may cooperate with the first and second cams, respectively. First and second catch recesses may be provided on the displacement bolt. A catch device may engage with a catch element, which may be biased into the first or second catch recess and which may secure the displacement bolt in the first or second position. The first and second guide tracks may cross one another in a crossing region. A third catch recess may be provided between the first and second catch recesses, wherein a first catch protuberance may be arranged between the first and the third catch recesses, and a second catch protuberance may be arranged between the second and the third catch recesses, wherein the catch element may engage with the third catch recess in the crossing region.

A method of controlling operation of an engine, the engine comprising: a combustion unit having an exhaust conduit and one or more combustion cylinders each having a piston, a fuel injector, an intake valve and an exhaust valve leading to the exhaust conduit; an exhaust gas treatment apparatus configured to receive fluid from the exhaust conduit and comprising a diesel oxidation catalyst module; and a controller configured to receive a temperature data value indicative of a temperature of gas within the diesel oxidation catalyst module. The method comprises: injecting fuel from the fuel injector into each of the one or more combustion cylinders in a main injection event to initiate via compression ignition a primary combustion event that drives the piston. The method further comprises using the controller to compare the temperature data value relative to a first temperature threshold value and a second temperature threshold value.