What Does A Oil Catch Can Do ?
All internal combustion engines that run off petrol are four stroke engines. This means that the piston has to go up and down a total of four times to complete a cycle. The piston first goes down with the intake valves open creating a vacuum. This draws in the cold dense air for combustion. Fuel is then injected into the cylinder.
The intake valves close and then the piston rises up towards the top of the cylinder. This compression creates an immense build-up of pressure in the cylinder. The only things containing this high pressure are the cylinder itself, the piston and the piston rings that seat against the walls of the cylinder, the intake and exhaust valves are closed as well. The pressure is so high that a very small amount of the air escapes around the piston and piston rings into the crankcase.The amount of blow-by increases as the engine RPMs rise. Also, an engine with more cylinders will have more blow-by.
Inside the crankcase you have the crank which is turning in the oil pan which is full of oil. This keeps it lubricated. Positive crankcase ventilation is necessary to ensure there isn't a build up of pressure in the crankcase. This would cause the crankcase to possibly crack under the pressure and create a huge dump of oil onto the street. The positive crankcase ventilation system removes the pressure from the crankcase and reverts it back through the intake tract via crank case vents.
An oil catch can catches or prevents the oil from re-entering the intake tract. A oil catch can is placed right after the PCV and before the intercooler. This means that a more pure air mixture will go through the intercooler and intake valves. A more pure air mixture entering the intake valves means no oil build up.
An oil catch can doesn't add any power so it is often overlooked when tuning vehicles. An oil catch can will ensure you are always running the most power possible by having a cleaner intake. Oil catch cans also look great in the
engine bay and contrary to beliefs, do serve an important purpose.