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Water separator as oil catch can

While changing valve springs, I noticed that the intake manifold was soaked in oil. This is due to the crankcase ventilation returning to the air intake. 

Burning oil is bad for the engine, as it causes carbon buildup. Combined it can lead to pre-detonation (engine knock) on high load.

I decided to add an oil catch tank to remedy the issue. Internet vendors charge stupid money for "tin cans" produced in China, so I usually design my own solution using the stock PCV and an aluminum bottle with steel wool to suspend and separate the oil vapor from the air.

This time, I came up with the idea of using a water separator for compressed air, $25 in a hardware store. 

The water separator contains a 5 micron filter to suspend the particles, and is rated for 1500 liters/minute (although at a much higher pressure). They are also designed to be easily drained. Perfect fit as an oil catch can.

The only modification required is to remove and seal off the bottom spring loaded drain valve (I used a socket head bolt with an o-ring).

After one season and a track day, I can only conclude that my 100k mile engine is in a very good shape. It consumes next to nothing of oil and only 3-4 spoons of oil collects in the catch can. At least it doesn't enter the air intake as before.