Oil Pan Design

One re-occuring "problem" with my turbo 400F has been getting the oil fully drained from the turbo itself. Turbos are fed pressurized oil, but there are no real seals at the sided of the bearing unit. It relies on a clean vertical drop on the oil return line to effectively evacuate the oil from the center section.

The stock oil pan contains 2L of oil, and the other 1.7L is contained in the lower crankcase, above the oil pan gasket line. This wasn't going to allow for a sufficient "drop" from the oil outlet on the turbo to the oil level, so I had to design my own oil pan.

The first pan that I built was too short, and the drain line was not vertical enough. The bike would smoke if it was pointed downhill at all, or if you really stopped hard.

I made the second pan longer and narrower to;

A.) Contain about 3.5L of oil, and maintain as low of an oil level as possible.

B.) Reach forward to a location roughly under the turbo outlet as to acheive a roughly vertical drop from the turbo outlet.

This is what I ended up with;

Cross section of empty oil pan.	Cross section with 4 liters of oil

As shown, this arrangment has 2 related problems. With 4 liters of oil, the bike will smoke under deceleration, and sometimes at idle after coming to a stop. Since there is no other evidence that it is burning oil, I have to cocnclude that oil is still backing up at times. If I lower the quantity from 4 liters to 3 - 3.5 liters it cures most of the smoking issue, but the oil light will come on if you stop really quickly.