---------------------------------------------------------- LycomingEngines-List Digest Archive --- Total Messages Posted Wed 05/18/11: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:20 AM - Intake o-ring install (Bubblehead) 2. 06:09 AM - Re: Intake o-ring install (FLYaDIVE) 3. 06:28 AM - Re: Intake o-ring install (Greg Young) ________________________________ Message 1 _____________________________________ Time: 05:20:04 AM PST US Subject: LycomingEngines-List: Intake o-ring install From: "Bubblehead" 2 years ago I had to replace 4 bad cylinders on my IO 360 A1F6D. The intake tubes are the type that use o-rings to seal inside the sump. Over the last 9 months 3 of the 4 o-rings have started leaking as evidenced by rough running and high EGTs during low power ops. When I removed and inspected the o-rings they appeared to have a dark line on the od and the id. When I rubbed the lines they turned out to be small cracks. In one area the skin of the o-ring peeled back. I don't know if I just got bad o-rings or did not install them correctly. The Lyc overhaul manual does not say much. I used a little silicon o-ring grease on them when I installed them. Could that have contributed to their failure? Do people on this forum use anything on the o-rings during installation? I wish I had the other style sump with the short hoses and clamps. That seems like a better system. I am thinking of finding a second hand one at a salvage shop. Any words of wisdom if I go that way? Is it worth the trouble? -------- John Dalman Keller, TX RV-8 N247TD Read this topic online here: http://forums.matronics.com/viewtopic.php?p=340255#340255 ________________________________ Message 2 _____________________________________ Time: 06:09:49 AM PST US Subject: Re: LycomingEngines-List: Intake o-ring install From: FLYaDIVE John: I can not comment on the silicone grease right now. But, give me a few weeks because I am running tests at work that address the exact same question. First thing would be the age of the 'O' rings - there should have been a shelf life on the package. Second, 'O' rings are usually made of Neoprene, Buna-N or Viton. All stand up very well to Gas, Diesel and Oil -AND - even Silicone. My bet is you have a loose fit and there is vibration which is causing ware and deggeration due to the "o"ring ROLLING sideways. The only reason to lubricate an 'O'ring is to prevent it from rolling over during install. AND the other basic rule is to lubricate with the similar materials that will be found in its operational environment. Also check the fit area for burrs and roughness. Barry =================== On Wed, May 18, 2011 at 8:16 AM, Bubblehead wrote: > jdalmansr@gmail.com> > > 2 years ago I had to replace 4 bad cylinders on my IO 360 A1F6D. The intake > tubes are the type that use o-rings to seal inside the sump. Over the last 9 > months 3 of the 4 o-rings have started leaking as evidenced by rough running > and high EGTs during low power ops. > > When I removed and inspected the o-rings they appeared to have a dark line > on the od and the id. When I rubbed the lines they turned out to be small > cracks. In one area the skin of the o-ring peeled back. > > I don't know if I just got bad o-rings or did not install them correctly. > The Lyc overhaul manual does not say much. I used a little silicon o-ring > grease on them when I installed them. Could that have contributed to their > failure? Do people on this forum use anything on the o-rings during > installation? > > I wish I had the other style sump with the short hoses and clamps. That > seems like a better system. I am thinking of finding a second hand one at a > salvage shop. Any words of wisdom if I go that way? Is it worth the > trouble? > > -------- > John Dalman > Keller, TX > RV-8 N247TD > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=340255#340255 > > ________________________________ Message 3 _____________________________________ Time: 06:28:05 AM PST US From: "Greg Young" Subject: RE: LycomingEngines-List: Intake o-ring install That other style sump is only on the parallel valve engines. I've gone the other way - putting the angle valve sump on a parallel valve engine and it requires modified intake tubes, i.e. neither the normal parallel or angle intake tubes fit. I assume your swap would need modified tubes as well. The angle valve sump is generally more desirable since the intake does not go through hot oil. It's part of the tuned induction that gets the extra horsepower in the angle valve engines. I did it to get the forward facing injector. I'm not sure if there is a parallel valve equivalent. There are a lot of those engines used without problems. I'd get new o-rings and install dry or with something other than silicone, like fuel lube or engine oil, and go fly. Greg Young -----Original Message----- From: owner-lycomingengines-list-server@matronics.com [mailto:owner-lycomingengines-list-server@matronics.com] On Behalf Of Bubblehead Sent: Wednesday, May 18, 2011 7:17 AM Subject: LycomingEngines-List: Intake o-ring install --> 2 years ago I had to replace 4 bad cylinders on my IO 360 A1F6D. The intake tubes are the type that use o-rings to seal inside the sump. Over the last 9 months 3 of the 4 o-rings have started leaking as evidenced by rough running and high EGTs during low power ops. When I removed and inspected the o-rings they appeared to have a dark line on the od and the id. When I rubbed the lines they turned out to be small cracks. In one area the skin of the o-ring peeled back. I don't know if I just got bad o-rings or did not install them correctly. The Lyc overhaul manual does not say much. I used a little silicon o-ring grease on them when I installed them. Could that have contributed to their failure? Do people on this forum use anything on the o-rings during installation? I wish I had the other style sump with the short hoses and clamps. That seems like a better system. I am thinking of finding a second hand one at a salvage shop. Any words of wisdom if I go that way? Is it worth the trouble? -------- John Dalman Keller, TX RV-8 N247TD Read this topic online here: http://forums.matronics.com/viewtopic.php?p=340255#340255 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message lycomingengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/LycomingEngines-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/lycomingengines-list Browse Digests http://www.matronics.com/digest/lycomingengines-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.