I had a very tiny oil leak for a while.. never enough to make a drip on the ground, but the engine was always wet. One day after a flight, I noticed a small spot.. “That’s new” so I decided to decowl it and look around..
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- Thread starter Taltruda
- Start date
Ouch, good catch Tom
I had that exact crack around the alternator attachment on a IO360 A1A. First I was sick to think it could have broken completely out when I had my wife and 2 kids under 5 years old flying to Lake Tahoe 20 minutes before I found it. After that sickness went away I got sick again thinking of the downtime and upcoming costs to remove the engine, replace the case, and now with it open, how much do I do to it? End up being a lot of unplanned expenses. It was 22 years ago and you just made that bad taste in the back of throat come back. Good luck with the repair.
That’s gonna leave a dent int eh old wallet….good catch Tom, and my sympathy for the downtime you’re about to undergo.
Yikes! Hmmmm, think I will remove my cowl and give things a good look see.
To quote a former head of state, "I feel your pain." I can't imagine the sick feeling you must have had (and probably still have) knowing the downtime and cost to get it airworthy again. But on the positive side, we'd all much read about it in this kind of post than the other kind of post where the title is RV Down...
Westcliffe01
Member
I would have the alternator checked for an imbalance or whether the case attachment point was stressed by misalignment.
AZSteve053
Well Known Member
I suspect bolt too long & bottomed inside case casting as tightened, unfortunately, I've seen this before.
I'll add my sympathies, hoping you the best recovery...
I'll add my sympathies, hoping you the best recovery...
I’m not sure what caused it yet.. the original builder seemed to do a great job with it.. the bracket wasn’t loaded against the boss.. the bolt does look a little long but I can thread it in all the way without the bracket, and it doesn’t bottom out or “pull” the boss away from the engine.. so I’m not sure the reason yet. The fixed pitch Sensenich was properly balanced..
As for the pain of discovery, it’s ok.. thankfully finances are good, and I’m glad I caught it in my hangar, at home, instead of having the oil blow out, leading to a seizure and having to dead stick it into a dry lakebed, hours from civilization, and then needing to figure a transportation plan back to home base!! (Or worse, crashing/wrecking the plane)
With gas prices at a record high ($7.30 and climbing) now isn’t the worst time to take a flying break!
I’m torn between having a local shop do the overhaul, having Aerosport Power do it, or taking on the experience myself, either way, I’ll take the opportunity to do some desired upgrades sooner than later!
Thanks for the kind responses and well wishes.. I’ll keep y’all updated!
As for the pain of discovery, it’s ok.. thankfully finances are good, and I’m glad I caught it in my hangar, at home, instead of having the oil blow out, leading to a seizure and having to dead stick it into a dry lakebed, hours from civilization, and then needing to figure a transportation plan back to home base!! (Or worse, crashing/wrecking the plane)
With gas prices at a record high ($7.30 and climbing) now isn’t the worst time to take a flying break!
I’m torn between having a local shop do the overhaul, having Aerosport Power do it, or taking on the experience myself, either way, I’ll take the opportunity to do some desired upgrades sooner than later!
Thanks for the kind responses and well wishes.. I’ll keep y’all updated!
Attachments
Good luck with it. I would send a pic to divco and see if that is repairable. Kind of thinking no, but often surprised what they can weld up and place back in service.
I’m taking the opportunity to upgrade to the B&C externally regulated setup anyway, but I’ll look closer at the old alternator.
Sam Buchanan
been here awhile
I appreciate your perspective, not everyone would handle this setback gracefully.
Best wishes for a smooth rebuild and getting your (new) ride back in the air soon.
OH MY that does seem to need a bit of attention. Never in a million years would I expect something like that to happen.
Hope my luck is better FIXIT
That’s a pretty remarkable failure. The boss was designed to carry that bracket load, and if this were a common weak point I’d expect we’d hear about it more often.
Without knowing the installation history, I wouldn’t want to assign cause. But I would be looking closely at over-torque, bracket misalignment, incorrect spacers, side-loading, or some other installation-induced stress.
It’s also a reminder that being a capable aircraft builder and being a trained mechanic are not quite the same thing. There’s overlap, but they are different skill sets.
Without knowing the installation history, I wouldn’t want to assign cause. But I would be looking closely at over-torque, bracket misalignment, incorrect spacers, side-loading, or some other installation-induced stress.
It’s also a reminder that being a capable aircraft builder and being a trained mechanic are not quite the same thing. There’s overlap, but they are different skill sets.
rmarshall234
Well Known Member
^^^^
Make sure that little bracket is installed between the alternator and starter.
Not required with B&C.
I sure wouldn't run without it...no matter the alternator type. It keeps the twisting moment down to a minimum, regardless of the alternator "style"
Would there be a downside?
Don't think it will even fit with the BC boss mount (std) bracket, and the supplied bolt is not long enough either.
Pretty sure the alt/starter bracket was mainly used on alt that were case mounted.
(if you anything other than BC then you should replace it)
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+1
Pretty easy to look at that failure and deduce that it has to somehow be related to the alternator. However, they use to hang much heavier generators on these things for decades and this is a pretty rare problem. My speculation would be on a unique casting flaw, but really tough to determine root cause on failures like this.
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Mine was a nippon denso style, and it didn’t have that little bracket, but I do think it’s a good idea to have one in there..
I'll be adding a brace to mine in the near future, and I'll be making it myself! Lycoming charges over $300 for a bent peice of flat bar with two holes in it...
