What is Crankcase Ventilation System in Cars: Types and Benefits

When a vehicle operates, it creates certain harmful gases and oil mist as the air-fuel mixture comes in contact with the combustion gases. These gases may leak further into the piston rings, which can harm your car engine and diminish fuel efficiency. To combat the occurrence, vehicles nowadays come installed with crankcase ventilation. 

The following sections detail the positive crankcase ventilation system and how it helps manage engine blow-by. 

Crankcase ventilation is the effective process of filtering out these accumulated gases called blow-by from the crankcase. Note that the blow-by gases can easily mix with other contaminants, causing harm to the vehicle and the environment. 

The function of a highly efficient crankcase ventilation system is to prevent that from happening.

Depending on your vehicle and its requirements for blow-by, either of the following types of crankcase ventilation system can be installed:

1. Open Crankcase Ventilation

OCVs are installed in vehicles where the blow-by goes into the atmosphere. This system can be low back pressure, low efficiency, or even come with a highly efficient coalescing system to collect huge amounts of oil mist. 

One of the primary benefits of the OCV system is that it decreases the chances of oil-build up in the aftercoolers and turbochargers of the engine.

2. Closed Crankcase Ventilation

Unlike OCVs, closed crankcase ventilation (CCV) is installed when the blow-by gases are taken back to the engine’s intake in such vehicles. The gases are routed up the compressor wheel and down the air cleaner. Some amount of blow-by may also be sent to the exhaust. 

Since this system follows the engine’s path, it helps monitor the total emissions a vehicle produces. This is why, as environmental regulations become stringent, the usage of such systems has increased.

A properly maintained crankcase ventilation system helps manage your vehicle’s engine performance to a great extent. It exhibits the following benefits:

Increases Fuel Efficiency

Before venting blow-by gases into the atmosphere or returning them to the engine's intake, crankcase ventilation systems, with their filters, clean them to remove impurities. The main issue with releasing blow-by gases is the creation of oil mist. The filter's job is to collect the oil mist that has been entrained in the blow-by and fuse it before returning it to the engine. Therefore, it plays a role in lowering oil consumption and, in turn, increasing fuel efficiency.

Improves Engine Performance

The crankcase ventilation helps remove pollution and contaminants from the crankcase. Efficiency and properly functioning ventilation are crucial in preventing the contaminants from settling on the engine’s aftercoolers and turbochargers, which helps retain the performance of a vehicle’s engine.

Protects the Environment

Crankcase ventilation systems employ high-efficiency filters to keep smoke, oil mist, and odours from polluting the environment. If the crankcase ventilation system malfunctions, the accumulated gases will release in the atmosphere. Further, untreated blow-by can accumulate on the vehicle’s engine. The oil can become a fire hazard and cause respiratory issues.

Helps Meet Key Environmental Regulations

Crankcase ventilation helps reduce blow-by emissions, as per regulations defined by national or regional agencies, such as EPA and IMO. Such requirements are defined on the basis of fuel type, stationary or marine installation.

The role of a crankcase ventilation system is huge when it comes to controlling pollutants and contaminants in the crankcase. A properly functioning system ensures your vehicle runs smoothly and performs well on-road.