---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Mon 04/25/16: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 11:43 AM - Securing Muffler Springs (KIRBY, DENNIS T GS-13 USAF AFMC AFNWC/EZS) 2. 12:20 PM - Re: Securing Muffler Springs (Stuart Harner) 3. 12:46 PM - exhaust springs (B Young) 4. 01:19 PM - Re: Securing Muffler Springs (John Hauck) 5. 06:46 PM - Re: Securing Muffler Springs (Richard Pike) ________________________________ Message 1 _____________________________________ Time: 11:43:57 AM PST US From: "KIRBY, DENNIS T GS-13 USAF AFMC AFNWC/EZS" Subject: Kolb-List: Securing Muffler Springs Kolb Friends - I'm sharing with you a tip that may prevent you some grief that I encountered recently on my Mark-3. One of my muffler springs broke on a recent flight and departed the engine. Went thru my Powerfin prop and it took a bite-sized chunk out of the leading edge of one prop blade. Damage was beyond repair - cost of a new blade was $250. All 8 springs on my Rotax-912 muffler are safety-wired, per common practice intended at securing the spring when (not if) they break. I always check the safety wire on each muffler spring as part of my preflight. Apparently on this day, one of these safety wires was worn partially through and still appeared secure when I checked it. When the spring broke in flight, the instantaneous energy must have been sufficient to break the already-weakened safety wire, resulting in the spring's departure from the engine. Double failure. So, here's the tip: I will no longer rely on ordinary safety wire to secure my Rotax muffler springs. I've upgraded to 1/16" braided cable to secure these springs. This is bicycle brake cable, available at any bike shop. I use one piece (about 10 inches long) for each pair of springs. The cable ends are joined and secured using a swaged ferrule. Cheap, easy to install, and most of all, WAY more secure than a single strand of .032 safety wire! Constant engine vibration will not wear thru it, as it does on safety wire. Fly safely ... Dennis Kirby Mark-3 / 912ul Sandia Park, NM ________________________________ Message 2 _____________________________________ Time: 12:20:04 PM PST US From: "Stuart Harner" Subject: RE: Kolb-List: Securing Muffler Springs Dennis, Very interesting. Thanks for sharing. Makes me want to use the flange/bolt method. Did you use RTV to keep the safety wire from bouncing around and wearing out? I have always done this, but don't like not being able to see the wire and judge its condition. Do you have any pictures of your new method? Question for the group. Do you think the stainless steel springs are better, and would it be a good idea to just replace the springs at say spark plug replacement intervals? Thanks, Stuart -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of KIRBY, DENNIS T GS-13 USAF AFMC AFNWC/EZS Sent: Monday, April 25, 2016 1:38 PM Subject: Kolb-List: Securing Muffler Springs --> AFNWC/EZS" Kolb Friends - I'm sharing with you a tip that may prevent you some grief that I encountered recently on my Mark-3. One of my muffler springs broke on a recent flight and departed the engine. Went thru my Powerfin prop and it took a bite-sized chunk out of the leading edge of one prop blade. Damage was beyond repair - cost of a new blade was $250. All 8 springs on my Rotax-912 muffler are safety-wired, per common practice intended at securing the spring when (not if) they break. I always check the safety wire on each muffler spring as part of my preflight. Apparently on this day, one of these safety wires was worn partially through and still appeared secure when I checked it. When the spring broke in flight, the instantaneous energy must have been sufficient to break the already-weakened safety wire, resulting in the spring's departure from the engine. Double failure. So, here's the tip: I will no longer rely on ordinary safety wire to secure my Rotax muffler springs. I've upgraded to 1/16" braided cable to secure these springs. This is bicycle brake cable, available at any bike shop. I use one piece (about 10 inches long) for each pair of springs. The cable ends are joined and secured using a swaged ferrule. Cheap, easy to install, and most of all, WAY more secure than a single strand of .032 safety wire! Constant engine vibration will not wear thru it, as it does on safety wire. Fly safely ... Dennis Kirby Mark-3 / 912ul Sandia Park, NM ________________________________ Message 3 _____________________________________ Time: 12:46:09 PM PST US Subject: Kolb-List: exhaust springs From: B Young Dennis fyi... the safety wire on my Springs do not have to be tight, that is the springs job... after putting the springs on, I run the safety wire through the spring. then run a bead of silicone rubber in the spring to encapsulate the wire. the silicone keeps things from vibrating. that is the belt, and for the suspenders.... I install a second piece of safety wire from the center point of one spring to the center point of the next. also silicone on the ends. the second wire is tight enough to pull the two springs very slightly out of column. this out of column should keep things from excessive vibration movement.. should one spring fail, the through ( belt safety) wire should keep it close... should that also fail the ( suspenders) should keep things out of the prop. Boyd Young ________________________________ Message 4 _____________________________________ Time: 01:19:35 PM PST US From: "John Hauck" Subject: RE: Kolb-List: Securing Muffler Springs Dennis K/Kolbers: Until I went the expensive SS spring route, I had problems with breaking springs. They didn't go through the prop because I use a lot of silicone seal to encapsulate the entire spring from one end to the other, including the hooks. No need for safety wire. I bought a set of SS springs to go with my new Titan exhaust system, some 800 hours ago. The springs are pricey, but they work. Well worth the money. As far as props go. The reason I use WARP Drive props is because I can't find a better one for performance and for durability/reliability. You could have put that spring through a WARP Drive blade and kept on flying. Probably take a little cosmetic work, but not a new blade. Here is the url for the springs: http://jbmindustries.com/SOCKET.html john h mkIII Titus, Alabama -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of KIRBY, DENNIS T GS-13 USAF AFMC AFNWC/EZS Sent: Monday, April 25, 2016 1:38 PM Subject: Kolb-List: Securing Muffler Springs --> AFNWC/EZS" Kolb Friends - I'm sharing with you a tip that may prevent you some grief that I encountered recently on my Mark-3. One of my muffler springs broke on a recent flight and departed the engine. Went thru my Powerfin prop and it took a bite-sized chunk out of the leading edge of one prop blade. Damage was beyond repair - cost of a new blade was $250. All 8 springs on my Rotax-912 muffler are safety-wired, per common practice intended at securing the spring when (not if) they break. I always check the safety wire on each muffler spring as part of my preflight. Apparently on this day, one of these safety wires was worn partially through and still appeared secure when I checked it. When the spring broke in flight, the instantaneous energy must have been sufficient to break the already-weakened safety wire, resulting in the spring's departure from the engine. Double failure. So, here's the tip: I will no longer rely on ordinary safety wire to secure my Rotax muffler springs. I've upgraded to 1/16" braided cable to secure these springs. This is bicycle brake cable, available at any bike shop. I use one piece (about 10 inches long) for each pair of springs. The cable ends are joined and secured using a swaged ferrule. Cheap, easy to install, and most of all, WAY more secure than a single strand of .032 safety wire! Constant engine vibration will not wear thru it, as it does on safety wire. Fly safely ... Dennis Kirby Mark-3 / 912ul Sandia Park, NM ________________________________ Message 5 _____________________________________ Time: 06:46:49 PM PST US Subject: Kolb-List: Re: Securing Muffler Springs From: "Richard Pike" Silicon? Safety wire? Um - no. How about some 5/16" bolts and springs from Ace hardware? The lugs that the bolts go through are cut off the ends of some big muffler clamps and welded to the pipes. Drill a hole in the end of the bolts and put a cotter pin through them. Replace them every year during condition inspection. Don't know how a 912 exhaust is configured, so it might not work for that application. -------- Richard Pike Kolb MKIII N420P (420ldPoops) Kingsport, TN 3TN0 Would you consider yourself to be a good person? https://www.youtube.com/watch?v=VWcDXT6pH7A Read this topic online here: http://forums.matronics.com/viewtopic.php?p=455466#455466 Attachments: http://forums.matronics.com//files/exhbolts_143.jpg ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-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/kolb-list Browse Digests http://www.matronics.com/digest/kolb-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.