Tom when I am out flying around to keep the Cessna engine from rusting
and for the $200 hamburger I would like to pop over and see your airplane.
Would that be OK?
Paul Lamar
Paul:
Glad to have you drop in most anytime. Call or e-mail first.
Right now I'm going through great learning pains trying to find a 12 Volt
scavange pump that will handle the oil output from my TE-06 Garrett turbo. I
just installed my third pump--a diesel fuel pump capable of 100 gph. It did
fine during initial evaluation, but now seems to be cavitating or something.
The last two engine runs resulted in copious amounts of oil bypassing the turbo
oil seals and making a huge mess.
Tom Parkes
That's strange. Take that thing apart and see if some oil has not coked
up and plugged the drain back line. What kind of oil are you running?
The Mobil 1 guy told me today Mobile 1 is good to 470 degrees F while
organic motor oil breaks down at 270 F.
Paul Lamar
Paul:
Here's the situation: I returned to turbo to Main Turbo in Visalia, CA. They say the seals are fine, the problem is oil is not getting out of the turbo. They sent a recommended restrictor for the oil supply line (about .185 dia hole), but oil was still bypassing the turbo oil seals--either with straight gravity feed through an AN-8 braided hose, or a small scavange pump like the one Chuck Harbert used on his Velocity. (Maximum run time to date is 10 minutes. Haven't exceeded 2000 rpm due to oil leakage--most of the time has been at 800 to 1000 rpm, so I doubt the oil has broken down. Max EGT reached has been around 865 degrees, max oil temp has not registered over 135.)
So I "upgraded" to the higher capacity 100 gph vane-type Carter pump mentioned. It initially tested well, sucking all the oil out of a collector jar into which I'd routed the turbo oil drain, but once permenantly mounted in place, it's pumping rate diminished to almost nothing. During another test yesterday, the pump started out very slowly, then after about 90 seconds resumed its high flow rate! I refilled the now empty plastic jar, turned on the pump, and it was back to a flow rate of practically nothing. Obviously not satisfactory. It may pump diesel fuel 100 gph, but not 30 wt mineral oil (for break-in).
Late yesterday, I discovered a possible reason for this inconsistency. The Carter pump in question circulates fuel (or oil) around the electric motor windings for cooling. I think 30 wt oil may be too viscous for the pump to generate normal flow rates, although this does not explain the highly variable results. So much for trying to use an electric fuel pump as an oil pump.
Does anyone know of any electric oil pumps intended, for example, for use in dry sump oil systems? Haven't found any in my Summit or Jeg's catalogs.
Tom Parkes
tparkes@earthlink.net
Bulent has one. It is a spur gear pump used for pre oiling engines.
Here are a few pictures.
BTW temporarily put a clear plastic hose on the lower part of the drain back
line so you can see what the oil looks like as it comes out of the turbo.
I suspect it is mostly foam therefore you need a line bigger than -8.
You also need a heat shield around the line near the turbo to prevent
heat radiation from the turbo housing.
Paul Lamar
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