Mailing List flyrotary@lancaironline.net Message #16971
From: Paul <sqpilot@bellsouth.net>
Subject: Re: [FlyRotary] Re: Oil leak
Date: Fri, 11 Feb 2005 12:27:37 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>, <prvt_pilot@yahoo.com>
 
----- Original Message -----
Sent: Wednesday, February 09, 2005 12:48 PM
Subject: [FlyRotary] Re: Oil leak

John,
Don't laugh, but I've heard that you can use flour to help locate the source of a leak.  You put flour on the suspect area, run it a little bit, and see where the flour has fresh oil on it.  I guess that the theory is that the flour soaks it up, and keeps it from spreading around.
 
The only down side would be that be fan in the back, blowing the flour away.
 
Just a thought.
 
Steve Brooks
 
 
Yes, and if you sift the flower through a screen afterwards and mix it thoroughly back with the wife's supply, she won't even know you borrowed it.  Paul Conner
 
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of John Slade
Sent: Wednesday, February 09, 2005 1:20 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Oil leak

Hi Guys,
I've been chasing an oil leak for a while now. It only happens when the engine is running. When I get back from a 20 minute flight the cowl has oil streaks down the outside, everything under the cowl has an oil film on it, and the turbo is seriously smokin'. I could probably make a similar mess by spraying about 1/2 cup of oil at the cowl and engine.
 
Today I took the plane up and down the runway a couple of times and did a couple of runups with the cowl off. I seem to be a little down on power - (3950 instead of 4050 on static). When I got back the mount plate below the turbo had fresh oil on it and I could see air bubbling through this oil at the joint of the mount plate and the engine, just by the turbo. See attached picture with arrow. In fact the entire join between the engine and the plate on the right (turbo) side seems wet with oil and there's another pool at the front which I don't think migrated from the back.
 
I get the feeling that this "bubbling" might become a fine jet of oil which points directly at the turbo when the engine's running, otherwise I don't see how oil could get up into the turbo housing and smoke like it does.  I'm trying to understand why there might be pressure here. The breather is definitely not blocked, and in fact, on this particular run, I'd even left the dipstick out. Could the bubbling air be a compression leak from the join between the rotor hosing and the backplate?  My oil level is maybe 1/4 - 1/2 inch below the level of the mount plate and the plane was on a slight grade making the back lower. The bubbling stopped after a few minutes and did not return when we turned the prop.
 
I'm resigned to pulling the lower cowl, sump and sump plate and redoing the RTV join (again), but I'm wondering - should there be pressure here? Is there some other problem causing this. Am I overfull with oil?  Could the turbo oil return be "landing" on the mount plate, then running back along the join? I'm planning a compression test next time I go down to the hangar.
 
Any other thoughts or suggestions?
 
Regards,
John (13.9 hrs and holding)


No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 265.8.6 - Release Date: 2/7/2005
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 265.8.7 - Release Date: 2/10/2005
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster