When you think of a performance aftermarket component you typically think of a part that increases the vehicle’s power, but some performance parts don’t. Instead they have a more critical purpose, increasing the reliability of your performance engine and components. The CorkSport Oil Catch Can Kit (OCC Kit) is just that type of component(s).
Why is an Oil Catch Can Kit critical for your Mazda? Despite the huge advancement Gasoline Direct Injection (GDI) technology there are still some downfalls. Compared to the more conventional port injection fuel systems, GDI is much more prone to engine oil fuel dilution. This is primarily due GDI injecting directly into the cylinder; in low speed operation and cold starts the fuel simply does not have enough time to fully atomize into a gas before ignition. This results in some excess fuel seeping past the piston rings into the oil along with any combustion chamber blow by the pistons. This is fuel dilution.
Here you can see the results of a CorkSport OCC installed for ~3000 miles on a 2018 Mazda 6 2.5T. This engine only has 500 miles and has an average commute of 15 miles & 20 minutes of mixed traffic and speeds.
Mazda’s OE design attempts to resolve some of this with a valve cover breather that vents directly into the turbocharger compressor inlet and a PCV (Positive Crankcase Ventilation) valve in the engine block that vents to the intake manifold.
Mazda’s setup depends on the fuel and water vapor inside the crankcase being drawn into the intake manifold and intake system to then be re-ingested by the engine. This has two major flaws:
- The direct crankcase ventilation via the PCV valve only works while cruising (no boost). Combustion gas blow by will occur most often while in boost under high throttle application when the PCV valve is closed.
- This forces the engine to re-ingest dirty air that carries contaminants in the form of fuel and water vapor along with carbon debris. These containments then build up on the inside of the intake manifold, cylinder head runners, and the intake valves slowly degrading performance over time.
The CorkSport OCC Kit provides you with two major features:
- Both the valve cover vent and the PCV valve are drawn from the turbo inlet directly ahead of the turbocharger compressor. Thus both the valve cover and PCV valve have constant vacuum in all driving conditions, both cruising and high throttle application.
- The oil catch can itself acts as a “filter” for the vapor and debris that would normally be directly ingested by the engine. The drawn crankcase vapor and debris is separates and collects in the catch can for easy removal during normal oil changes.
As you saw above, there is a significant amount of vapor and fine debris that is being filtered out of the crankcase air that would have normally been ingested. As you continue down the path of modifying and demanding more form your Mazda, the need for a OCC System only becomes more and more critical.