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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 ...
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 intervening carburetor or throttle body leading to the intake manifold.
Failure to use the correct specification oil has been known to cause PCV (positive crankcase ventilation), VVT (variable valve timing) system, gasket and sealing system, and other internal combustion component premature clogging and other failures. Some of the additives in those specs are designed to aid in keeping systems lubricated and clean.
Chevrolet went so far as to carry the positive crankcase ventilation system (PCV) over to the cross-ram induction system to retain emissions compliance mandated for U.S.-produced cars beginning in 1967, that also provided full-throttle crankcase pressure venting to the intake air to burn its vapors.
Therefore, an inverted V engine would have a minimum of two scavenge pumps and a pressure pump in the pump stack. Dry sump systems may optionally be designed to keep the engine's crankcase at lower than atmospheric pressure (vacuum), by sealing the crankcase and allowing the scavenge pumps to draw out both oil and gases.
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 ...