What Is a Catch Tank?
A catch tank is primarily used in internal combustion engines (gasoline and diesel engines).
In the field of motorsports, regulations often require its installation for safety reasons, and various companies offer aftermarket parts for this purpose.
Uses of Catch Tanks
During the combustion process of an engine, blow-by gases are typically reintroduced into the intake route, such as the intake manifold inlet, through the PCV valve.
However, this process also reintroduces oil mist and sludge generated inside the engine into the intake air. This can lead to oil burning at high loads and high RPM, resulting in white smoke. Additionally, the oil mist can contaminate the intake passage, causing the air cleaner to become oil-soaked, reducing intake efficiency, and causing oil to leak from the intake inlet.
To prevent these issues, catch tanks are installed in the engines of racing cars and other vehicles that heavily rely on high-revolution engines.
Principles of Catch Tanks
Catch Tanks can be broadly classified into two types: those with baffle plates inside and those without baffle plates. The former, known as a “separate type,” is characterized by the presence of a partition plate called a baffle, which separates the blow-by gas inlet pipe from the outlet pipe.
While the “separate type” separates gas and liquid by directing oil mist against the baffle plate, the latter type separates gas and liquid by extending the blow-by gas inlet pipe deeper than the outlet pipe.
However, the latter type may be susceptible to blockage of the blow-by gas inlet pipe due to oil accumulation, potentially causing an increase in crankcase pressure as blow-by gas loses its escape route. Therefore, it is necessary to drain the oil more frequently than with the separate type.
While general-purpose products are available from various manufacturers, it is essential to select the appropriate capacity based on engine displacement and oil volume requirements and securely attach it to a solid part of the engine or vehicle during installation.