---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Thu 12/26/24: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:17 AM - Re: Re: Engine mount bolt loosens (D McFadyean) 2. 11:20 AM - Re: Engine mount bolt loosens (Area-51) 3. 12:53 PM - Re: Re: Engine mount bolt loosens (Bud Yerly) 4. 04:10 PM - Re: Re: Engine mount bolt loosens (Peter Z) ________________________________ Message 1 _____________________________________ Time: 03:17:07 AM PST US From: D McFadyean Subject: Re: Europa-List: Re: Engine mount bolt loosens I think that misses the point, Which was that, despite proper locking, some installations fret the mount against the engine, resulting in bolts coming "loose". I've previously found one on a Pioneer, despite being tight for the preceding several years. BTW, the combination of Loctite plus the swarf that Rotax leaves down the tapped mounting bolt holes is irremovable without significant risk of galling the threads upon bolt extraction. Duncan McF. > On 26/12/2024 05:39 GMT Area-51 wrote: > > > > Consult the Rotax installation manual and use the specified thread lock product. > > Alternatively purchase new cap screws and "hardened" washers to required specification that have drilled heads to permit lock wiring. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=515170#515170 > > > > > > ________________________________ Message 2 _____________________________________ Time: 11:20:42 AM PST US Subject: Europa-List: Re: Engine mount bolt loosens From: "Area-51" All valid; points noted. On occasion have found bolt has loosened and departed the airframe leaving three secure in place. Why does the bolt loosen? Vibration and the sum total of heat expansion and contraction cycles of individual components. Check the flat washer used under the cap screw heads; they should be hardened washers under the spring washers. I now make it a routine item at 25hrs to check the torque on all 4 engine to crankcase frame bolts. Clean the thread well with brake clean and compressed air before refitting. Ensure the spacer block between crankcase and engine frame has been fitted during installation; visual inspection with light and mirror. it cannot come out even if bolt departs the frame. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=515173#515173 ________________________________ Message 3 _____________________________________ Time: 12:53:29 PM PST US From: Bud Yerly Subject: Re: Europa-List: Re: Engine mount bolt loosens All points well made. I found a solution but you won't like it as it is a bit tedious in some cases. I have found looseness in the following bolts: The M10 Bolts securing the ring mount to the engine are torqued and many ha ve lock washers on newer airplanes. It is rare but should I find one loose , I use 10 mm Nord-lock wedge locking washers, rather than Loctite 243 alon e as called for. Nord-locks are expensive ($25 for 20) but are very secur e on steel and work especially well on aluminum. See Granger or Nord-Lock direct. The Rotax Heavy Mx Manual has torque requirements for bolt sizes u sed and further amplify in the specific installation of components like cyl inder head bolts. The M10 Allen head bolts securing the Engine Mounting Frame to the ring mou nt using the M10 "Binx" nuts will loosen often. These nuts are particularl y frustrating on the 914 near the turbo. I drill the bolt head and use .02 0 safety wire through the slot in the "Binx" nut back to the hole in the Al len head. This is not hard drilling the Allen head, but I highly recommend proper security of the bolt and cobalt 1/16 inch drill bits for the chore. This is tedious with the engine on but can be done with long pliers and a lot of patience. I may try 10mm Nord-Locks one of these times. Exhaust nuts on the 912S are frustrating and difficult to safety wire. How ever, I have had luck when the whole stud comes off with the nut to simply buy new nuts, remove the old corroded nuts, clean the stud threads inspect and if good reinstall with Loctite 243 on the head side (the Loctite will f ail with heat but...) Secure the stud and allow the Loctite to cure overni ght. I then install the new nuts, and I will peen the nut lightly if the p rong ends are not grabbing well. On one aircraft a customer drilled the 8m m bolts through the corner for 0.020" safety wire. Very secure, but I have found my proper install and if necessary,peening of "sloppy fitting exhaus t nuts" (as tolerances are not what they used to be) to be quite effective . Exhaust vibration on the 912S is demanding on the exhaust system. Pay a ttention to springs, the sealing points and look for soot. I've written on this in the past and still find satisfaction with exhaust sealant and lapp ing my joints. Springs require some silicone down the outside and just in case I still put a loop of safety wire down through the springs to keep eve rything secure. Never use a Nylock nuts forward of the firewall. In high heat they melt, a nd after exposure for a few years under the hood, will tend to fail. Lock washers, Nord-Locks or safety wire are best. I find Nut plates and MS210 s queeze nuts hold up extremely well over time. Squeeze nuts, MS210 type, ar e very good unless reused, then proper re-peening will suffice for a tempor ary fix for lack of a new nut on hand. This is why I do a 25 hour oil change and inspection. Use Torque Seal on y our nuts to determine if they have loosened. That way the inspection is qu ite fast. If a bolt or nut has loosened apply a fix as stated above and the n Torque Seal Again. Your airplane may look like a bunch of orange or yell ow dots on all the bolts, but a stitch in time saves 9 as they say. Best Regards, Bud Yerly ________________________________ From: owner-europa-list-server@matronics.com on behalf of Area-51 Sent: Thursday, December 26, 2024 2:20 PM Subject: Europa-List: Re: Engine mount bolt loosens > All valid; points noted. On occasion have found bolt has loosened and departed the airframe leaving three secure in place. Why does the bolt loosen? Vibration and the sum tota l of heat expansion and contraction cycles of individual components. Check the flat washer used under the cap screw heads; they should be hardened was hers under the spring washers. I now make it a routine item at 25hrs to check the torque on all 4 engine t o crankcase frame bolts. Clean the thread well with brake clean and compres sed air before refitting. Ensure the spacer block between crankcase and eng ine frame has been fitted during installation; visual inspection with light and mirror. it cannot come out even if bolt departs the frame. Read this topic online here: https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fforums.ma tronics.com%2Fviewtopic.php%3Fp%3D515173%23515173&data=05%7C02%7C%7C3854b 21b979b4feb2c5508dd25e2c73f%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63 8708378132634723%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLj AuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sda ta=nyXVKOq2lcf0w03vR2xUA%2BXTKgFfxpRcgjijK5lyEf4%3D&reserved=0 %2Fwww.matronics.com%2FNavigator%3FEuropa-List&data=05%7C02%7C%7C3854b21b 979b4feb2c5508dd25e2c73f%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63870 8378132651474%7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuM DAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata =Yj%2Fw1aYLUHTCadXWflFfhvkN1zVgoY%2BiCfTPs3FVfWs%3D&reserved=0 %2Fforums.matronics.com%2F&data=05%7C02%7C%7C3854b21b979b4feb2c5508dd25e2 c73f%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638708378132668403%7CUnkn own%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zM iIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=TCioi00KtQxPgO3AP1 YiW7XXYaQVJZ1VMaIRjfv3vyI%3D&reserved=0 %2Fwiki.matronics.com%2F&data=05%7C02%7C%7C3854b21b979b4feb2c5508dd25e2c7 3f%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638708378132684663%7CUnknow n%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiI sIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=oE4Yes8%2F3pU1mOYLCN uvcWTSoTnI2jv8wq87I1QGNBQ%3D&reserved=0 F%2Fmatronics.com%2Fcontribution&data=05%7C02%7C%7C3854b21b979b4feb2c5508 dd25e2c73f%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638708378132702270% 7CUnknown%7CTWFpbGZsb3d8eyJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJ XaW4zMiIsIkFOIjoiTWFpbCIsIldUIjoyfQ%3D%3D%7C0%7C%7C%7C&sdata=%2BBBDNz%2F8 7c4un0O2fXMyi5STRcofJ4sQ1EON2%2BiMHBw%3D&reserved=0 ________________________________ Message 4 _____________________________________ Time: 04:10:12 PM PST US From: Peter Z Subject: Re: Europa-List: Re: Engine mount bolt loosens --- MIME Errors - No Plain-Text Section Found --- A message with no text/plain MIME section was received. 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