An oil return valve for a crankcase ventilation system of an internal combustion engine is provided that is essentially situated in the crankcase (3) and includes a valve cylinder (1) and at least one valve pipe (2).

A breach detection system for an internal combustion engine having a crankcase, an intake manifold, a positive crankcase ventilation valve, a crankcase ventilation tube with a flow control system therein, and a pressure sensor between the flow control system and the crankcase. The flow control system subdivides the crankcase ventilation tube into a plurality of parallel conduits—a first conduit having a normally closed check valve that opens under a first preselected pressure drop in a first direction from the air intake to the crankcase, and a second conduit having either a second check valve that opens under a second preselected pressure drop in a second direction opposite the first direction or a restriction profile having a third preselected pressure drop that is the same in both the first and second direction. When the pressure sensor detects no pressure drop there is a breach in the system.

An engine is disclosed having a water cooling system allowing efficient cooling of the exhaust valves to prevent temperature gradients from building in the engine. Water is therefore pumped through the engine though first and second water cooling cores which discharge through the head. A water manifold is positioned over the discharge opening and includes couplings for the radiator supply, radiator return, water pump supply, oil cooler supply and oil cooler return. The engine has separate chambers to isolate the pistons and cylinders, and reed valves cover the chambers and allow the blow-by gases and oil to enter the oil pan during the power stroke of the engine cycle.

The invention provides a system for ventilation of a crankcase (217) of an internal combustion engine, the system comprising—an air inlet guide (203, 212) adapted to guide air to at least one cylinder (220) of the engine,—a closed circuit conduit (209) for guiding crankcase gas from the crankcase (217) to the air inlet guide (203, 212),—wherein the system comprises gas detection means (2181, 2182, 2183) positioned in the air inlet guide (203, 212), for detecting crankcase gas in the air inlet guide.

This breather device separates engine oil included in a blow-by gas. The breather device comprises a first route, an acceleration route, a branching route, and turn-back routes. The blow-by gas flows to the first route. The acceleration route is connected to a downstream side of the first route, and has a flow channel cross-sectional area smaller than that of the first route. The branching route is connected to a downstream side of the acceleration route, configured including a wall part orthogonal to the acceleration route, and branched into two routes by the wall part. The turn-back routes are connected to one route branching at the branching route, and are turned back so as to be parallel to the acceleration route and to head in the opposite direction from a progressing direction.

To provide an electromagnetic valve capable of preventing damage due to stress of a buffer member. An electromagnetic valve includes a solenoid having a case, a flow path member, and a columnar valve element that is housed in the valve element housing portion of the flow path member and moves with a plunger of the solenoid to open and close a flow path. A seat member with which the plunger comes into contact is disposed in the case of the solenoid. The seat member includes a core portion with which the plunger comes into contact, and a plurality of protruding portions protruding radially outward from an outer peripheral surface on the radially outer side of the core portion.

A blowby gas treatment device includes a pressure control valve, a fresh air induction pipe, a first blowby gas pipe, a second blowby gas pipe, a shutoff valve, a one-way valve, and a PCV valve. A leak diagnosis includes a first-stage diagnosis to determine whether or not falling of a pressure in a crank case after closing of the shutoff valve under a non-supercharging condition is normal. A second-stage diagnosis is implemented by moving the pressure control valve from a fully opened state into a fully closed state, and determining whether an intake air quantity in each state is equal to each other. When the intake air quantity in each state is equal to each other, presence of an in-system leak is determined. When a fully closed state intake air quantity is different from a fully opened state intake air quantity, presence of an out-of-system leak is determined.

An engine assembly includes an engine structure including an engine block defining a combustion chamber and a crankcase, and a cylinder head mounted to the engine block. An oil fill tube is connected to the engine structure. A separator assembly includes a separator chamber having a positive crankcase ventilation tube inlet connected to a positive crankcase ventilation passage and having a positive crankcase ventilation tube outlet. The separator chamber includes an internal baffle and a check valve in a bottom of the separator chamber in communication with a drain chamber, the drain chamber being in communication with the oil fill tube.

An internal combustion engine has a control device, an EGR valve that adjusts an EGR rate, a PCV valve that adjusts an opening degree of a first PCV passage that communicates an inside of a crankcase and a downstream side of a throttle valve. The control device operates the throttle valve in a closing direction in response to a deceleration request. The control device adjusts an opening degree of the PCV valve based on an immediately preceding EGR rate immediately before reception of the deceleration request.

To provide an electromagnetic valve capable of preventing damage due to stress of a buffer member. An electromagnetic valve includes a solenoid having a case, a flow path member, and a columnar valve element that is housed in the valve element housing portion of the flow path member and moves with a plunger of the solenoid to open and close a flow path. A seat member with which the plunger comes into contact is disposed in the case of the solenoid. The seat member includes a core portion with which the plunger comes into contact, and a plurality of protruding portions protruding radially outward from an outer peripheral surface on the radially outer side of the core portion.