Positive crankcase ventilation (PCV) systems have been employed on naturally-aspirated engines for over half a century. The gases in the crankcase exit the engine into the engine intake due to the slightly elevated pressure in the crankcase. Flow is controlled via a PCV valve in a PCV duct. In pressure-charged engines, PCV flow stops when pressure in the intake exceeds that of the crankcase. Such stagnation leads to sludging and deposit formation. According to an embodiment of the disclosure, reverse flow through the system is allowed by installing a second PCV valve in parallel with the normally-provided PCV valve, with the second PCV valve allowing an opposite direction of flow. Oil separators are provided on both PCV ducts to and from the engine to remove oil from blowby gases for flow in either direction.

The present disclosure provides an engine system of a vehicle including an engine having combustion chambers for generating driving torque by burning fuel; an intake line in which fresh air flowing into the combustion chambers flows; an exhaust line in which exhaust gas exhausted from the combustion chambers flows; a recirculation line connecting the exhaust line and the intake line; a turbocharger including a turbine disposed at the exhaust line and rotated by the exhaust gas from the combustion chambers, and a compressor disposed at the intake line and rotated together with the turbine and compressing fresh air; an exhaust gas recirculation valve disposed at the connection of the recirculation line and the intake line to adjust an exhaust gas recirculation gas amount supplied to the intake line through the recirculation line; and a remaining gas elimination apparatus for supplying gas remaining in the intake line to the recirculation line.

A turbocharger housing includes a discharge outlet having a tubular configuration that extends tangentially from a peripheral portion of the housing and an externally threaded section adjacent the end of the discharge outlet to allow the discharge outlet to be connected either to a hose by a hose clamp or to a flanged pipe via an internally threaded flange engaging the externally threaded section of the discharge outlet and a V-band clamp securing the flanges together.

An outboard motor including an internal combustion engine for propelling a ship is equipped with an air-guiding system using a covering hood surrounding surfaces of the internal combustion engine and auxiliary units. The covering hood is provided with airflow inlet and outlet openings in its interior, and a fan driven by the internal combustion engine influences airflows in the covering hood. An air-guiding system includes channeling devices for partial air flows. First partial air flows are fed as intake air to an engine intake system, and second partial air flows act, with the aid of the fan, on surfaces of the internal combustion engine and the auxiliary units heated by operation of the internal combustion engine. The heated airflows are conveyed by the fan and a third channeling device as exhaust air via an outlet opening in the covering hood outside of the covering hood or into the atmosphere.

An internal combustion engine for an outboard motor for driving a vessel has an air guide system acting by way of a covering hood surrounding surfaces of the internal combustion engine and ancillary units. Covering hood inlet and outlet openings permit airflows to move in an interior space of the covering hood, and a fan driven by the internal combustion engine influences the airflows in the covering hood interior space. Airflows enter the interior space of the covering hood via an inlet opening and a first routing arrangement. Assisted by the fan, part of the airflows acts on the surfaces of the internal combustion engine and of the ancillary units. A second routing arrangement routs another portion of the airflows, as intake air, to an engine suction system. Airflows heated by engine and ancillary unit surfaces are conveyed by the fan and a third routing arrangement outside the covering hood.

Methods and systems are provided for improving the efficiency of canister purge completion. Based on engine operating conditions, a canister is purged to a compressor inlet or a throttle outlet. During purging conditions, as canister loads change, a purge flow through the canister is varied so that a fixed preselected portion of total engine fueling is delivered as fuel vapors.

Methods and systems are provided for controlling a temperature of gases within a heat exchanger, a ratio of gases output by the heat exchanger, and selectively charging/discharging gases from the heat exchanger to one or both of an intake system or an exhaust system. In one example, a method may include controlling operation of an energy recovery device coupled to the heat exchanger in response to engine operating conditions, and increasing or decreasing flow of exhaust gas and/or compressed intake air into the heat exchanger in response to energy recovery device output.

An object is to provide an air intake duct structure for a centrifugal fluid machine, capable of swirling the fluid introduced into the impeller in the reverse direction to increase the pressure ratio when the flow rate is high and swirling the fluid in the forward direction to avoid a surging when the flow rate is low, as well as securing a wide operating range, without using mechanical means. The centrifugal fluid machine 1 includes an impeller 12 mounted to a rotation shaft and a housing 4 for housing the impeller 12. The air intake duct structure 10 is for directing a fluid “f” to a rotational center 12a of the impeller 12 housed in the housing 4 via an intake duct portion 4a of the housing 4 protruding in an axial direction of the rotation shaft, the fluid “f” flowing in a substantially orthogonal direction to a rotational axis line 3. The air intake duct structure 10 comprises an inflow part 14 extending in the substantially orthogonal direction to the rotation axis line 3 and a transition part 16 connecting the inflow part 14 and the intake duct portion 14a of the housing 4. There is a virtual plane 20 orthogonal to the rotational axis line 3 and passing through a flow path cross-section of the inflow part 14, where an intersection 22 of the virtual plane 20 and the rotational axis line 3 is positioned within the transition part 16.

Methods and systems are provided for using a crankcase vent tube pressure or flow sensor for diagnosing a location and nature of crankcase system integrity breach. The same sensor can also be used for diagnosing air filter plugging and PCV valve degradation. Use of an existing sensor to diagnose multiple engine components provides cost reduction and sensor compaction benefits.

A compressor arrangement for an internal combustion engine, having a compressor which is arranged in a compressor housing and has a low pressure side and a high pressure side, and having a negative pressure provision unit, which has a propellant channel that is fluidically connected, on the one hand, via a propellant inlet fitting to the high pressure side of the compressor and, on the other hand, via a propellant outlet fitting to the low pressure side of the compressor and has a nozzle, and which has a negative pressure channel opening into the propellant channel fluidically between the propellant inlet fitting and the propellant outlet fitting.