A cylinder head assembly includes a cylinder head casting, and an injector sleeve within an injector bore in the cylinder head casting. The injector sleeve includes a first sleeve end, and an injector clamping surface formed by an inner sleeve surface adjacent to a cylindrical second sleeve end. The injector sleeve further includes a sleeve clamping surface in contact with an upward facing middle deck surface of the cylinder head casting, and a reaction wall extending between the injector clamping surface and the sleeve clamping surface to transfer an injector clamping load to the upward facing middle deck surface.

There is provided a water cooled engine including a cylinder head with minimized thermal strain. A head water jacket includes an inter-exhaust-port-wall water channel between a first exhaust entrance port wall and a second exhaust entrance port wall. A cylinder head includes a cooling water injection passage provided at a bottom wall of the cylinder head. The cooling water injection passage is positioned on the exhaust end side, and includes a passage entrance provided on the exhaust end side, and a passage exit directed toward the inter-exhaust-port-wall water channel. An exhaust port wall includes a heat dissipation fin extending from a first exhaust entrance port wall toward an exhaust end. The space between the heat dissipation fin and a second exhaust entrance port wall forms a water channel entrance of the inter-exhaust-port-wall water channel.

There is provided a water cooled engine including a cylinder head with minimized thermal strain. A head water jacket includes an inter-exhaust-port-wall water channel between a first exhaust entrance port wall and a second exhaust entrance port wall. A cylinder head includes a cooling water injection passage provided at a bottom wall of the cylinder head. The cooling water injection passage is positioned on the exhaust end side, and includes a passage entrance provided on the exhaust end side, and a passage exit directed toward the inter-exhaust-port-wall water channel. An exhaust port wall includes a heat dissipation fin extending from a first exhaust entrance port wall toward an exhaust end. The space between the heat dissipation fin and a second exhaust entrance port wall forms a water channel entrance of the inter-exhaust-port-wall water channel.

A cylinder head in a cylinder head assembly includes an upper deck, a fire deck, gas exchange conduits, and a coolant cavity extending peripherally around the gas exchange conduits. The cylinder head also includes an igniter socket having an igniter post, and a radially outward sleeve step continuously circumferential of an igniter bore center axis. A cooling moat is formed between the igniter post and the sleeve step. The coolant cavity includes a valve bridge through-channel and a valve bridge part-way channel each fluidly connected to the igniter socket to provide coolant flow into and out of the cooling moat passively.

A cylinder head in a cylinder head assembly includes an upper deck, a fire deck, gas exchange conduits, and a coolant cavity extending peripherally around the gas exchange conduits. The cylinder head also includes an igniter socket having an igniter post, and a radially outward sleeve step continuously circumferential of an igniter bore center axis. A cooling moat is formed between the igniter post and the sleeve step. The coolant cavity includes a valve bridge through-channel and a valve bridge part-way channel each fluidly connected to the igniter socket to provide coolant flow into and out of the cooling moat passively.

An engine power module includes a water jacket, a cylinder liner, and a cylinder head. The water jacket forms a coolant supply conduit arranged in a lower coolant annulus extending around the cylinder liner and an upper coolant annulus extending around the cylinder head. The cylinder head has formed therein an injector bore, and a plurality of drill holes convergent on the injector bore. A lower coolant cavity in the cylinder head forms a coolant flow path extending circumferentially around the injector bore between a cavity inlet opening fluidly connected to the coolant supply conduit, and a cavity connection opening fluidly connected to an upper coolant cavity. The arrangement provides flows of coolant through the drill holes to cool an injector sleeve, and separate coolant flows through the lower coolant cavity and upper coolant cavity.

A prechamber sparkplug assembly includes a sparkplug, and a sparkplug housing having a prechamber tip. The sparkplug housing includes a plug bore centered on a longitudinal axis of the sparkplug housing and receiving the sparkplug, an inside radial wall extending around the plug bore, and an outside radial wall. A cooling cavity is formed between the inside radial wall and the outside radial wall. Coolant ports extend through the outside radial wall and fluidly connect to the cooling cavity to place the cooling cavity in fluid communication with a water jacket in a cylinder head.

A prechamber sparkplug assembly includes a sparkplug, and a sparkplug housing having a prechamber tip. The sparkplug housing includes a plug bore centered on a longitudinal axis of the sparkplug housing and receiving the sparkplug, an inside radial wall extending around the plug bore, and an outside radial wall. A cooling cavity is formed between the inside radial wall and the outside radial wall. Coolant ports extend through the outside radial wall and fluidly connect to the cooling cavity to place the cooling cavity in fluid communication with a water jacket in a cylinder head.

A cylinder head assembly includes a cylinder head casting, and an injector sleeve within an injector bore in the cylinder head casting. The injector sleeve includes a first sleeve end, and an injector clamping surface formed by an inner sleeve surface adjacent to a cylindrical second sleeve end. The injector sleeve further includes a sleeve clamping surface in contact with an upward facing middle deck surface of the cylinder head casting, and a reaction wall extending between the injector clamping surface and the sleeve clamping surface to transfer an injector clamping load to the upward facing middle deck surface.

A cylinder head assembly includes a cylinder head casting, and an injector sleeve within an injector bore in the cylinder head casting. The injector sleeve includes a first sleeve end, and an injector clamping surface formed by an inner sleeve surface adjacent to a cylindrical second sleeve end. The injector sleeve further includes a sleeve clamping surface in contact with an upward facing middle deck surface of the cylinder head casting, and a reaction wall extending between the injector clamping surface and the sleeve clamping surface to transfer an injector clamping load to the upward facing middle deck surface.