- Joined
- Mar 17, 2007
- Messages
- 758
- Reaction score
- 47
As most of you know, it took me over a year (in between deployments) to remove my sick A-65 and replace it with a pre-owned, but zero-times Dons' Dream Machines C-85 stroker. The engine has 16-5 hours on it using Aeroshell stright mineral oil and has been run according to Don's recommendation of at least 75% power for the first 20-25 hours with no pattern work or powerr off descents.
I was flying last Saturday towards the end of an hour long flight at 2,300 rpm when the engine suddenyl got louder and while the rom wasn't affected, there was a noticeable "clacking". I stated a slow climb, did all the usual, carb heat, adjusted rpm, nothing changed the noise. RPM went up and down fine, oil pressure and temp was normal, just a loud clanking that got louder the more power I applied.
Fortunately I was close to the airport and made a normal power on landing and taxied to the hangar. Externally I noticed a front cowling clip had come loose and was relieved to think it was probably just the cowling banging around, but ran out of time to trouble shoot further.
Fast forward to an hour ago, I pulled the Cub out, preflighted and prepared to go taxi and possibly do a pattern hop to see if the sound returned. With the fuel on, mags and throttle off I primed the engine and pulled through my usual 4 blades. On the first blade I noticed an odd sound. paying closer attention, on the next one a very odd snap back occured, on the third, the prop locked straight up and down. if I'd had a radial I'd swore it was hydraulic lock.
It's not locked like it seized, there's some lash, but the shaft is physically locked. I guess I can be happy it didn't happen while I was flying, but on the other hand, that was 16K of my savings, and over a year in the making. I bought it from an owner in NC who originally bought it from DDM for his Cub project which he never finished. It was pickled properly, kept in a heated hangar, and only had the 4 hours of test stand time.
I think I'm probably screwed, but will call Don on Monday to see if he has any recommendations. Couldn't even investigate further, felt like I'd just been punched and just closed the hangar door and drove home to think about it.
Mike-
I was flying last Saturday towards the end of an hour long flight at 2,300 rpm when the engine suddenyl got louder and while the rom wasn't affected, there was a noticeable "clacking". I stated a slow climb, did all the usual, carb heat, adjusted rpm, nothing changed the noise. RPM went up and down fine, oil pressure and temp was normal, just a loud clanking that got louder the more power I applied.
Fortunately I was close to the airport and made a normal power on landing and taxied to the hangar. Externally I noticed a front cowling clip had come loose and was relieved to think it was probably just the cowling banging around, but ran out of time to trouble shoot further.
Fast forward to an hour ago, I pulled the Cub out, preflighted and prepared to go taxi and possibly do a pattern hop to see if the sound returned. With the fuel on, mags and throttle off I primed the engine and pulled through my usual 4 blades. On the first blade I noticed an odd sound. paying closer attention, on the next one a very odd snap back occured, on the third, the prop locked straight up and down. if I'd had a radial I'd swore it was hydraulic lock.
It's not locked like it seized, there's some lash, but the shaft is physically locked. I guess I can be happy it didn't happen while I was flying, but on the other hand, that was 16K of my savings, and over a year in the making. I bought it from an owner in NC who originally bought it from DDM for his Cub project which he never finished. It was pickled properly, kept in a heated hangar, and only had the 4 hours of test stand time.
I think I'm probably screwed, but will call Don on Monday to see if he has any recommendations. Couldn't even investigate further, felt like I'd just been punched and just closed the hangar door and drove home to think about it.
Mike-
