Tom Parkes wrote:

Paul:

I need some help from you engineer types to determine oil flow rates
through my Garrett TE-06 turbo, and also in selecting a satisfactory 12V
scavange pump.

 My previous post on first engine start noted that oil was leaking
through my turbo oil seals.  I returned the turbo to Main Turbo
(Visalia, CA), but they tell me the seals are fine and that my problem
is too much oil in to the turbo and too little out.  They kindly
enclosed an oil supply line restrictor (approx. .185" diameter) to use
if other alternatives didn't solve my problem  The oil supply line into
the turbo is AN-4, while the drain line is AN-8.  Unfortunatly, the
space between the compressor and turbo does not permit a larger drain
fitting.

I've conducted several engine runs with the restrictor in the oil supply
line, never exceeding 2000 rpm.  First I tested straight gravity drain,
and as before got excessive oil leakage.  Next, I installed a small 12V
scavange pump (rated at 30 gph/14 psi for gasoline), and got almost
identical results.  At Main Turbo's suggestion, I ran the gravity drain
from the turbo into a large plastic jar, and ran the scavange pump feed
line into the same jar.  The oil level in the jar increased fairly
rapidly, but I did not measure exact rates.  Obviously, I need a higher
capacity pump.  But how large?

A high school physics teacher friend estimated the oil flow (30 weight
mineral oil) through the restrictor to be about 8 gph @ 90 psi.  Would
that be about correct?  If so, is there a 12V pump anyone would
recommend?

Thanks for your help.

Tom Parkes
tparkes@earthlink.net

Here is an old picture. If it is the same I think your problems are 
drain back Tom. You may have to go with a steel tube drain back line.

As I recall a -8 is 1/2 inch ID which is marginal for such a large turbo.
You need 5/8 or 3/4 inch ID pipe. A 5/8th ID is 50% more area as
a 1/2 inch ID pipe. A 3/4 inch ID pipe is well over twice the area of a 1/2
inch ID pipe. 2.25 times as much to be more exact.

Best way is welded steel tubing. What kind of fitting is the drain back fitting
on the turbo housing?  Also I cannot tell from this picture where it is going 
into the pan. It should go into the pan just above the oil level.
Here is the drain back pipe on the small stock 87 Mazda turbo.

Also you need a SS sheet metal shield around this drain back or the
red hot radiation from the turbine housing will boil the oil in the drain
back pipe and prevent proper drain back.

Paul Lamar
 
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