195 kr
PCV Valve for cars converted from open crankcase ventilation to a type of closed crankcase ventilation. This is a threaded PCV valve that fits those cars that have Cadillac's original crankcase ventilation rebuild. Compare with your old valve.
Replace the PCV Valve when you do a major service on your Cadillac. A functioning closed crankcase ventilation is good both for the environment and for the oil quality in your engine.
Crankcase ventilation is a system that vents overpressure gases out of an internal combustion engine's crankcase. These gases consist of combustion gases that leak past piston rings and valve seals. If the crankcase was not vented, overpressure would build until a gasket or stuffing box collapsed, resulting in oil leakage. In addition, the combustion gases contain, among other things, unburned hydrocarbons, which can dilute the engine oil and reduce its life. Crankcase ventilation can be carried out open or closed. Open crankcase ventilation was original to Cadillac through 1962. It consists of a tube that runs from the back of the valve lifter cover under the intake. The pipe then goes on to the undercarriage of the car. The speed wind blowing past the mouth of the tube causes a negative pressure that sucks air out of the crankcase. The air is drawn into the crankcase through the vented oil filler cap. The disadvantages of this design are that the air flow is less than it should be and that the harmful crankcase gases are discharged into the atmosphere. Therefore, Cadillac introduced a type of closed crankcase ventilation in 1963. Which means that the pipe that went down under the engine was connected to the engine's intake vacuum under the carburettor and was equipped with a spring-loaded valve (PCV Valve). PCV is short for Positive Crankcase Ventilator. The crankcase gases are then burned in the engine's combustion chamber. However, this "semi-closed" ventilation is not effective under all operating conditions - at full throttle, or when the piston rings are worn, the combustion gases can escape through the oil filler cap. In 1967, Cadillac came up with a new system where incoming air to the crankcase is supplied via a hose that goes from the air cleaner to a valve cover. The closed crankcase ventilation has strongly contributed to extending oil change intervals and environmental impact. In the USA, from model year 1968 it is mandatory to have closed crankcase ventilation on passenger cars.
