Doug:
Here is my experience with crankcase
vacuum.
I installed the oil vent with a ¾”
tube ground at about a 30 degree angle to the wind velocity to give a crankcase
vacuum. I had a lot of oil on the belly and I speculate the oil/water/air
mixture was sucked out before it could condense on any metal surfaces.
I installed a homemade oil condenser
between the crankcase and the outlet tube and collected little oil/water
products in the condenser drain. Was my flow too high for the condenser?
I then changed the angle of the outlet
tube to about 10 degrees. The oil on the belly was less and I collected less
than a teaspoon of condensate in the condenser after a two hour flight.
I have now made the outlet flat with the
belly but have not flown since the modification. I am expecting less oil on the
belly. As far as the power is concerned, I doubt if I am changing crankcase
pressure enough to notice it – more testing to come.
From: Lancair Mailing
List [mailto:lml@lancaironline.net] On Behalf
Of Douglas Brunner
Sent: Monday, May 15, 2006 5:02 PM
To: Lancair Mailing List
Subject: [LML] Re: Positive
Crankcase Vacuum
I hope to be able to judge for myself the increase in
horsepower on a dyno. Mike Moore of AvWorks has extended to me the
offer of being able to run my engine (under close
supervision) on a dyno after it is built. I am looking forward to this
for many reasons,
not the least of which is being able to see exactly how much horsepower I am
getting.
The other benefits you mention are nice as well and you
forgot to mention how nice and clean the belly of my plane will look.