With this engine run the engine mount bolts went thru the case and thru the rubber bushings without a bushing stop in bushings, hence the tighter the nut is tightened, more rubber bushing is compressed. The next step is to install a bushing in the rubber bushings to tighten bolt against and eliminate the bolt wanting to move in engine case. In theory it should work better.
Seems like there is bolt rocking starting. those bolts must have some bending going on given the geometry of the shock rubbers versus the mount point of the engine . Sure wish the engine case was set up for "continental" type shock rubbers. Sigh. Kudos for your continued experimentation!
Think I'd look at collecting the exhaust in a collector ring and blowing it out one pipe down low like the full size radials.. a wee bit of work but it would sure look good (er)........ Still working on my LE XL, hope to fly it to an EAGLE gathering sometime or maybe all the way to OSHKOSH......( lol ).................... GOOD JOB LES ! Fly Safe
Have you tried lycoming mount rubbers? They have a larger ID and are just bigger overall. You might could make a bushing assembly rhat tightens down all the way and still have flex in the rubber with a sleeve going through the whole works
I agree that larger lugs would be an improvement. At this point, the bolts act as though they were cantilevered, implying that the holes in the lugs will become conical ovals over time. If the lugs were bolted solid to a front portion of the mount, and the motion, meaning rubber mounts, could be moved to elsewhere within the mount, then the lugs would be OK and safe. The lugs appear to be part of an aluminum casting, hence they will take the worst of the wear. Let the mount take the wear, not the lugs.
Use full threaded bolts, run a nut or some threaded stop down to solidify the bolt to the engine lug-THEN stack the isolator/spacers similar to what's already there to the round ring mount?? I can also see too much rigidity applied to that lug could induce some lug cracking.. A solid bolt (extension of the lug) should isolate all movement to within the replaceable rubber- and keep the through-bolt parallel through the rubber as it wears/relaxes/degrades. I dunno. I need to see if this was figured out, as this is 3 yrs old when I wrote this edit- yup! he got it figured out!
