The ultimate Mazda MX-5 crankcase ventilation upgrade!

During combustion in the engine cylinders, small amounts of combustion gases can always leak past the piston rings. These gases build up pressure in the crankcase and can be harmful to the engine if not removed. This can lead to, for example, leaking seals or an engine that starts burning more oil. Proper venting of these gases is therefore crucial. (see video below)

Crankcase Ventilation System in a Turbocharged Mazda MX-5

If a Mazda MX-5 owner chooses to add or upgrade a turbo, it is essential to ensure that the crankcase ventilation system functions properly. A well-functioning system ensures optimal performance, minimizes the risk of damage due to overpressure, and extends the engine's lifespan.

In turbocharged engines, the crankcase ventilation system is even more crucial. Why? Below are the two main reasons:

1. Increased pressure: Turbocharged engines generate more power by compressing the air supplied to the cylinders, resulting in higher combustion pressure. This increases the likelihood of more combustion gases leaking past the piston rings into the crankcase.
   
2. Higher temperatures: The pressure increase in turbocharged engines is often accompanied by an increase in engine temperature. These higher temperatures can increase the rate at which oil breaks down and can also contribute to a larger amount of harmful vapors in the crankcase.

Why the standard crankcase ventilation is not optimal for your Mazda MX-5?

In its standard form, all oil vapors in the Mazda MX-5's crankcase ventilation system return to the intake and are then burned by the engine.

Why does crankcase ventilation return to the intake?

1. Environmental considerations: The gases exiting the crankcase contain unburnt fuel, oil, and other contaminants. By returning these gases to the engine's intake, they are re-burned in the cylinders, which helps to reduce the emission of harmful substances. This process meets emission standards and is more environmentally friendly.
2. Negative pressure in the intake tract: Returning the crankcase gases to the intake tract helps maintain a slight negative pressure in the crankcase. This promotes piston ring sealing and reduces oil leakage and evaporation.

How can this contaminate the intake tract?

1. Oil and contaminants: While these gases are re-burned, they are often mixed with a fine mist of oil. When this oil comes into contact with the colder parts of the intake tract, it can condense and accumulate. This results in a sticky deposit on the intake valves, intake ports, and the intake tract itself.
2. Carbon deposits: Over time, the oil and other contaminants that accumulate in the intake tract can carbonize, especially in direct injection engines where the intake valves are not "washed" by fuel. These carbon deposits can restrict airflow and reduce engine efficiency.
3. Reduced performance: Once the intake tract is contaminated, this can lead to reduced performance, an irregular idle, loss of power, and decreased fuel efficiency.

Given the aforementioned shortcomings, the standard crankcase ventilation system of a Mazda MX-5 is certainly not ideal for achieving maximum performance and ensuring the longevity of engine components. Moreover, the original crankcase ventilation system was designed for a naturally aspirated engine. Therefore, if you are considering installing a turbo on your Mazda MX-5, it is wise to optimize this system.

Level7Performance Quikvent & Catch Can

We now know that oil vapors from the crankcase ventilation system can contaminate the engine. Prevent this by installing a Catch Can. You connect this Catch Can to the Mazda MX-5 valve cover connections. This separates and collects oil. Excess overpressure exits the Catch Can via a filter.

Installing a Catch Can reduces intake tract contamination. However, flow shortcomings remain a challenge. This is where Level7Performance QuikVent offers a solution. This replaces the Mazda MX-5's standard oil cap. With this CNC-machined product, you get two AN10 connections. You also retain a stylish oil cap.

The Level Seven QuikVent flows better, which benefits crankcase pressure and, not unimportantly; connecting a catch can is not only incredibly easy with AN-10 connections but also very stylish!

PS: If you want to upgrade the crankcase ventilation system, I recommend ordering the installation tool as well.

The installation manual can be found here and below.