Mailing List flyrotary@lancaironline.net Message #16050
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: 2 cycle oil in Sump was Re: [FlyRotary] Re: oil analysis results
Date: Wed, 26 Jan 2005 08:22:16 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Message
Based on the experience of Finn, Tracy and myself, there is no doubt that unburnt 2 cycle oil does (at least for us) migrate to the sump with pre-mix.  Apparently a small amount of the 2 cycle oil in the fuel is deposited on the metal surfaces including the sides of the combustion chamber.  As the rotor oscillates its seals apparently sweeps some of this oil into the center housing to mix with the cooling sump oil dumped there and then flows to the sump.
 
The rate of 2 cycle oil build up seems dependent upon the ratio of the mixture.  I find that mixing 1 oz per gallon, I will have approx 1/2 cup of additional oil in the sump after 10-15 hours.  If I reduce the oil to 3/4 oz per gallon, it seems to reduce it to practically nothing.
 
The first time Tracy told me his engine was making oil, I would have been very skeptical (had it been anyone other than Tracy).  Then I begin noticing that after a period of time my oil level would be up to the drain level of my PSRU return, so I would drain 1/2 cup or so.
 
FWIW
 
Ed A
 
 
----- Original Message -----
Sent: Wednesday, January 26, 2005 2:12 AM
Subject: [FlyRotary] Re: oil analysis results

 

 

a portion of the fuel/air mixture is pushed into the crankcase (for lack of a better term).

 

Finn made a statement a few weeks back that he had to drain oil from his sump because of the fuel that had gotten past the side seals.  And he’s flying.

 

Bob Perkinson

 

Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster