Abstract: A system is provided for monitoring changes in the operation of a valve system of an engine. An accelerometer provides vibration-related signals that are obtained by a microprocessor or similarly configured device and compared to a reference or baseline magnitude. The obtaining step can comprise the steps of measuring, filtering, rectifying, and integrating individual data points obtained during specific windows of time determined as a function of the rotational position of the crankshaft of the engine. These windows in time are preferably selected as a function of the position of exhaust or intake valves as they move in response to rotation of cams of the valve system.

Abstract: A cooling system for a marine engine incorporates first and second thermally responsive valves which are responsive to increases in temperature above first and second temperature thresholds, respectively. The two thermally responsive valves are configured in serial fluid communication with each other in a cooling system, with one thermally responsive valve being located upstream from the other.

Abstract: An engine is provided with a plurality of cylinders and cylinder liners that are shaped to define a plurality of spaces between the liners and the engine block. These spaces provided an insulative barrier that at least partially restricts the flow of heat from the liner into the engine block. This allows the liners to operate at elevated temperatures while avoiding a deleterious increase in the cooling water temperature as it flows through passages within the engine block.

Abstract: A method is provided for avoiding water ingestion through an exhaust system into the cylinders of an engine during an engine shutdown procedure. Air is allowed to flow into the air intake conduit, either through an opened throttle plate or through an opened idle air control valve to raise the pressure within the intake conduit toward equalization with atmospheric pressure. This reduces the negative pressure of the intake conduit relative to the exhaust conduit and inhibits ingestion of water upwardly from a body of water through the exhaust conduit into the cylinder.

Abstract: A cooling water distribution system provides a single cavity from which water is directed to a plurality of auxiliary devices. The cavity is formed within a housing structure that has a perforate surface shaped to be inserted into a primary water conducting channel through which water flows from a water pump to an internal combustion engine. The perforate surface does not extend into the water stream induced by the water pump but, instead, is shaped to conform to an inner surface of the water conducting cavity. Holes in the perforate surface are shaped to allow water to flow from the main channel of the water conducting cavity into the cavity of the housing structure from which the water is distributed through a plurality of water conduits to various auxiliary devices requiring cooling water.

Abstract: The temperature regulation system is provided which places a flow controlling valve at a location which can be different than the location of the temperature being controlled. In other words, a valve can be located at a remote position relative to, cooling passages of an engine block or head. Signals from temperature sensors are provided to a microprocessor of an engine control module and the engine control module controls the operation of the valve in response to the measured temperatures. The engine control module can select different temperature ranges as a function of selected operating conditions of the engine, such as engine speed. In addition, the engine control module can cycle the valve in order to free it of debris when it is sensed that the valve is not responding in an expected manner.