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The first refinement in crankcase ventilation was the road draught tube. This is a pipe running from the crankcase (or the valve cover on an overhead valve engine) down to a downwards-facing open end located in the vehicle's slipstream. When the vehicle is moving, airflow across the open end of the tube creates suction (a "draught" or draft ...
Without ventilation this can pressurize the crankcase and cause issues such as lack of piston ring sealing and damaged oil seals. To avoid this, manufacturers created a crankcase ventilation system. Originally this was often a very basic setup where a filter was placed on the top of the cam case and the pressure and vapors were vented to ...
A crankcase is the housing in a piston engine that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block. Two-stroke engines typically use a crankcase-compression design, resulting in the fuel/air mixture passing through the crankcase before entering the cylinder(s). This design of the engine does ...
Crankcase ventilation system: The crankcase ventilation valve is incorporated in the aluminum cylinder head cover. [5] System components used to achieve SULEV tailpipe emission requirements: Dual downstream catalytic converters "Warm up" catalytic converters—high-cell-density technology; Upstream oxygen sensors—wide band technology
EGR has nothing to do with oil vapor re-routing from a positive crankcase ventilation system (PCV) system, as the latter is only there to reduce oil vapor emissions, and can be present on engines with or without any EGR system. However, the tripartite mixture resulting from employing both EGR and PCV in an engine (i.e. exhaust gas, fresh air ...
Manifold vacuum, or engine vacuum in a petrol engine is the difference in air pressure between the engine's intake manifold and Earth's atmosphere.. Manifold vacuum is an effect of a piston's movement on the induction stroke and the airflow through a throttle in the intake manifold of an engine.
The first effort at controlling pollution from automobiles was the PCV (positive crankcase ventilation) system. This draws crankcase fumes heavy in unburned hydrocarbons – a precursor to photochemical smog – into the engine's intake tract so they are burned rather than released unburned from the crankcase into the atmosphere. Positive ...
Diagram of a crankcase scavenged valveless 2-stroke engine in operation. Some SI engines are crankcase scavenged and do not use poppet valves. Instead, the crankcase and the part of the cylinder below the piston is used as a pump. The intake port is connected to the crankcase through a reed valve or a rotary disk valve driven by the engine. For ...