Oil-return: How high?

[914turboEFI]

I am planning a turbo install on my type-iv 914. I am concerned about the proposed location of the turbo with regard to oil return. How high above the sump does the turbo need to be to not run into oil return problems?

-Ben

[volkaholic]

The outlet of the turbo oil drain needs to be above the oil sump level. The drain line itself must flow down hill, if even only slightly. So for all practical purposes, taking into account space required for fitting, hose clamps, etc, the bottom of the turbo needs to be 1-2" above the oil level. Assuming you are running a wet sump system, you can pull the dip stick out & line it up on the out side of the case & get a pretty close idea on what the oil level is, then go from there.

One final note, I have seen articles in magazines on turbo systems with there own dedicated scavenger pump to allow pumping the oil "uphill" back into the engine. I've also seen a set up where the turbo had a self contained oil system with synthetic oil. No oil lines in or out, you just change it like the engine oil. I have no idea how well these ideas really work.

[Steve C]

Hi
It is very important to get this right because if the waste oil backs up you will flood the turbo bearings resulting in large amounts of smoke. Make sure you use a minimum of 1/2 hose for the the return line.
Steve C