X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [207.46.163.183] (HELO na01-bn1-obe.outbound.protection.outlook.com) by logan.com (CommuniGate Pro SMTP 6.0.9e) with ESMTPS id 6852463 for flyrotary@lancaironline.net; Wed, 30 Apr 2014 03:02:37 -0400 Received-SPF: none receiver=logan.com; client-ip=207.46.163.183; envelope-from=SBoese@uwyo.edu Received: from BL2PR05MB098.namprd05.prod.outlook.com (10.255.232.15) by BL2PR05MB098.namprd05.prod.outlook.com (10.255.232.15) with Microsoft SMTP Server (TLS) id 15.0.929.12; Wed, 30 Apr 2014 07:02:01 +0000 Received: from BL2PR05MB098.namprd05.prod.outlook.com ([169.254.2.32]) by BL2PR05MB098.namprd05.prod.outlook.com ([169.254.2.32]) with mapi id 15.00.0929.001; Wed, 30 Apr 2014 07:02:01 +0000 From: "Steven W. Boese" To: Rotary motors in aircraft Subject: RE: [FlyRotary] SWITCHEROO becomes low oil pressure Thread-Topic: [FlyRotary] SWITCHEROO becomes low oil pressure Thread-Index: AQHPZBWSxtZL9zPP/0OImHNF1g8txJsproZs Date: Wed, 30 Apr 2014 07:02:00 +0000 Message-ID: <1398841322673.27970@uwyo.edu> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [70.196.192.184] x-forefront-prvs: 0197AFBD92 x-forefront-antispam-report: SFV:NSPM;SFS:(10009001)(6009001)(428001)(199002)(377454003)(189002)(99286001)(99396002)(20776003)(79102001)(31966008)(50986999)(54356999)(76482001)(75432001)(16236675002)(46102001)(74502001)(80022001)(85852003)(74662001)(83072002)(101416001)(77982001)(36756003)(87936001)(2656002)(81542001)(83322001)(92566001)(92726001)(19580395003)(19580405001)(76176999)(86362001)(80976001)(81342001)(80792004)(18121605002);DIR:OUT;SFP:1101;SCL:1;SRVR:BL2PR05MB098;H:BL2PR05MB098.namprd05.prod.outlook.com;FPR:261FF22C.AC39E689.B0FB3D7B.8CF45721.20473;MLV:sfv;PTR:InfoNoRecords;A:1;MX:1;LANG:en; received-spf: None (: uwyo.edu does not designate permitted sender hosts) Content-Type: multipart/alternative; boundary="_000_139884132267327970uwyoedu_" MIME-Version: 1.0 X-OriginatorOrg: uwyo.edu --_000_139884132267327970uwyoedu_ Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable It may be worth considering monitoring the oil temperature and temperature = as it leaves the front cover. With the stock RX7 oil cooler, my oil pressu= re at that location was always over 150 psi at RPM over 2800. The oil temp= erature in that location also would reach 270 degrees even when the oil tem= perature returning from the cooler was acceptable. The high oil temperatur= es and pressures could make failure of the front cover o-ring more likely a= nd also contribute to oil escaping from the vent or other locations. Steve Boese RV6A, 1986 13B NA, RD1A, EC2 ________________________________ From: Rotary motors in aircraft on behalf of = shipchief@aol.com Sent: Tuesday, April 29, 2014 7:42 PM To: Rotary motors in aircraft Subject: [FlyRotary] SWITCHEROO becomes low oil pressure I enjoyed a nice 1.2 hour flight yesterday, but ended with oil or exhaust s= mell. Never a good thing, conjuring up images of a fuel fire or carbon mono= xide poisoning. Today I gave it another routine cowl raising inspection, and noticed the us= ual oil film. It's everywhere, and comes from no-where. It was cooking off = from the under slung muffler. I wiped it off, and I think the culprit is th= e crankcase vent from the oil fill tube. I had to shorten the tube so it wo= uld fit under the cowl. Now the vent line is pretty low, just over the cent= er iron into which the oil tube fits. It discharges thru a tube and hose ar= rangement to the right side of the cowl outlet on the bottom. I think the a= irflow in this area is turbulent and sometimes back flows into the cowl and= spreads all over. I added another heat shield to keep the radiant glow of the exhaust system = off of the fuel system. I also noticed the throttle opened about 40 degrees shy of full open. So I = adjusted the cable lock nuts to give more; however, the throttle is suffici= ently oversized that it didn't make an appreciable difference. After a joyful morning of small improvements and cleaning, I decided to mak= e an hour flight, have some lunch and do a second hour flight. Well, that was arrogant of me. I made it about 30 minutes and noticed the o= il pressure had dropped from 62 or better to 38 PSI. Water & oil temps were= in the 160F& 170F zone. So I headed for the nearest airport and slowed 'wa= y down. The oil pressure increased to 39-42, so I eased it on home. Off wit= h the cowl, oil checks full, everything on the outside of the engine looks = good. I got a mechanical oil pressure gauge, and yes, 40 PSI at the oil fil= ter housing, while reading 39 PSI on the Engine Monitor. I'm stripping the 'front' cover off, expecting to find the famous oil O rin= g blown....Maybe I should have used larger diameter oil discharge hose... The bolt that takes the 19mm socket on the pulley hub defeated me this even= ing. I hope it's not a left hand thread...I'll continue tomorrow. --_000_139884132267327970uwyoedu_ Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

It may be worth considering monitoring the oil temperature and temperatu= re as it leaves the front cover.  With the stock RX7 oil cooler, = my oil pressure at that location was always over 150 psi at RPM over 2= 800.  The oil temperature in that location also would reach 270 degrees even when the oil temperature returning from the c= ooler was acceptable.  The high oil temperatures and pressures could m= ake failure of the front cover o-ring more likely and also contribute to oi= l escaping from the vent or other locations.

 

Steve Boese
RV6A, 1986 13B NA, RD1A, EC2
 

From: Rotary motors in ai= rcraft <flyrotary@lancaironline.net> on behalf of shipchief@aol.com &= lt;shipchief@aol.com>
Sent: Tuesday, April 29, 2014 7:42 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] SWITCHEROO becomes low oil pressure
 
I enjoyed a nice 1.2 ho= ur flight yesterday, but ended with oil or exhaust smell. Never a good thin= g, conjuring up images of a fuel fire or carbon monoxide poisoning.<= /div>
Today I gave it another routine cowl raising inspection, and noticed t= he usual oil film. It's everywhere, and comes from no-where. It was cooking= off from the under slung muffler. I wiped it off, and I think the culprit = is the crankcase vent from the oil fill tube. I had to shorten the tube so it would fit under the cowl. Now t= he vent line is pretty low, just over the center iron into which the oil tu= be fits. It discharges thru a tube and hose arrangement to the right side o= f the cowl outlet on the bottom. I think the airflow in this area is turbulent and sometimes back flows int= o the cowl and spreads all over.
I added another heat shield to keep the radiant glow of the = exhaust system off of the fuel system.
I also noticed the throttle opened about 40 degrees shy of full open. = So I adjusted the cable lock nuts to give more; however, the throttle is su= fficiently oversized that it didn't make an appreciable difference.
After a joyful morning of small improvements and cleaning, I decided t= o make an hour flight, have some lunch and do a second hour flight.
Well, that was arrogant of me. I made it about 30 minutes and noticed = the oil pressure had dropped from 62 or better to 38 PSI. Water & oil t= emps were in the 160F& 170F zone. So I headed for the nearest= airport and slowed 'way down. The oil pressure increased to 39-42, so I eased it on home. Off with the cowl, oil checks full, every= thing on the outside of the engine looks good. I got a mechanical oil press= ure gauge, and yes, 40 PSI at the oil filter housing, while reading 39 PSI&= nbsp;on the Engine Monitor.
I'm stripping the 'front' cover off, expecting to find the famous oil = O ring blown....Maybe I should have used larger diameter oil discharge hose= ...
The bolt that takes the 19mm socket on the pulley hub defeated me this= evening. I hope it's not a left hand thread...I'll continue tomorrow.
--_000_139884132267327970uwyoedu_--