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UPDATE -- RV-7 engine failure, Emer landing, no damage/injuries

Great outcome! As others echoed, I bet the crank dowel pin experienced fatigue and SB 475c wasn't properly accomplished. How many hors ago was the prop strike? Or when was the prop replaced?
Another reason for making sure those prop low pitch stops are set correctly (about 2650rpm static). Even if you tried to pull the prop back, in your case with no oil pressure, nothing would have happened, as you need oil pressure to coarsen the propeller. So don’t second guess that you didn’t do it.. wouldn’t have made a difference. Great job with the landing!
 
Great outcome! As others echoed, I bet the crank dowel pin experienced fatigue and SB 475c wasn't properly accomplished. How many hors ago was the prop strike? Or when was the prop replaced?
Another reason for making sure those prop low pitch stops are set correctly (about 2650rpm static). Even if you tried to pull the prop back, in your case with no oil pressure, nothing would have happened, as you need oil pressure to coarsen the propeller. So don’t second guess that you didn’t do it.. wouldn’t have made a difference. Great job with the landing!
Very few "aircraft grade" bolts in Lycoming's. Most are Lycoming bolts, whatever they may be.
 
Very few "aircraft grade" bolts in Lycoming's. Most are Lycoming bolts, whatever they may be.
I was told at Lycoming school years ago that most of the external case bolts are simply Grade 2. Internal, highly-stressed “Jesus bolts” ….I only buy them from Lycoming because of…..superstition? 😉
 
That is a grade 5 bolt in your pic, not a cheap offshore ungraded bolt. In fact it looks just like the one lyc sells. The fact that it has a mfg identifier (ks) implies a reputable brand. Home Depot bolts rarely have these. There is no special bolt for that gear. It is lyc part number “std-5/16,” which in lyc terms means a run of the mill grade 5 bolt, possibly grade 2. The higher strength or specialized stuff usually gets a more traditional part number.

What you feel on the rods is likely normal- .003” of clearance, so they can wobble a bit.
1. See post #50 in this thread regarding counterfeit "KS" fasteners.

2. The correct Lycoming crank-gear bolts have a flat head face with the 4 digit Lycoming part-number stamped on them.

Skylor
 
1. See post #50 in this thread regarding counterfeit "KS" fasteners.

2. The correct Lycoming crank-gear bolts have a flat head face with the 4 digit Lycoming part-number stamped on them.

Skylor
thanks. didn't know that and missed that post.
 
I was told at Lycoming school years ago that most of the external case bolts are simply Grade 2. Internal, highly-stressed “Jesus bolts” ….I only buy them from Lycoming because of…..superstition? 😉

I just looked at my core 540 in the garage and all of the screws I can see have the 6 lines for a grade 8 screw and "LE" in the middle. This was a factory rebuilt engine from ~15 years ago.
 
Correct crank gear bolt-I am finding Lycoming pn 01C26131, verified by both Air Power and Spruce. $91.17 from Air Power.
 
Correct crank gear bolt-I am finding Lycoming pn 01C26131, verified by both Air Power and Spruce. $91.17 from Air Power.
Interesting. Just bought one for an O-360-A1A and it is a STD-2213, now superceded by STD-2246. That is for the smaller 5/16 bolt on the non CW crank
 
Great job getting down in 1 piece. Everything else going forward can be fixed. From what you have discovered so far my opinion is you have to overhaul this engine. Who knows what other corners may have been cut. If you want confidence (and you do) that its put together correctly you going to have to go down to the last bolt. Good luck.

Don Broussard
Older A&P/IA/ATP
RV9 Rebuild in Progress
57 Pacer
 
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