Abstract: An internal combustion engine for use with hydrogen fuel includes at least one cylinder assembly including a combustion chamber, a cylinder, a cylinder head, and a reciprocating piston assembly. Two inlet ports within the cylinder head are selectively closable by a corresponding inlet valve, and at least one outlet port in the head is selectively closable by a corresponding outlet valve. At least one spark plug is mounted to the cylinder head, and the cylinder head comprises a first face and a second face inclined relative to one another and meeting at an apex. The two inlet ports are located within the first face and outlet port is located within the second face. Each inlet port is configured to generate a tumbling motion of the fuel air mixture prior to ignition. The cylinder head is secured by six fasteners, such as six bolts to an engine block defining the cylinder.

Abstract: An air inlet system for an internal combustion engine comprising an air inlet duct which has an upstream end including an opening and a downstream end for connection to an air flow control component and further comprising a mass air flow sensor assembly, the mass air flow sensor being located closer to the downstream end than the upstream end.

Abstract: An air inlet system for an internal combustion engine comprising an air inlet duct which has an upstream end including an opening and a downstream end for connection to an air flow control component and further comprising a mass air flow sensor assembly, the mass air flow sensor being located closer to the downstream end than the upstream end.

Abstract: An air inlet system for an internal combustion engine comprising an air inlet duct which has an upstream end including an opening and a downstream end for connection to an air flow control component and further comprising a mass air flow sensor assembly, the mass air flow sensor being located closer to the downstream end than the upstream end.