Cylinderhead ventilation - greasy plenum...

[oldeskewltoy]

In longitudinal installations, on long moderate to high "G" load left turns it is possible to fill up the head with oil and then the breather acts more like a spout that pours oil into the intake.

The easy answer to this problem is to add a drainage port on the rear of the intake side of the head, similar to the smallport heads drain. Once you do this there is far less chance of filling the head to the level that it pours into the intake tract.