My last annual
- Thread starter USMCmech
- Start date
Cherokee_Cruiser
Bronteroc
Congrats! May I ask if it’s a Cherokee Cruiser? 1969 or newer?
drunkenbeagle
Gang Member
I was quoted $15,000 for a valve on a hydraulic brake line. At least with piston engines, the parts are reasonably common and available most of the time.
CFI A&P
Exploring the world one toilet at a time.
I know you've been around the block a few times, but if you think the shop is trying to take you for a ride - reach out. Too many owners do realize they can have some input with the annual. Not every squawk is a $20k overhaul.
DE727UPS
Well-Known Member
Thanks. I'm taking it to the shop that has done the last 5 or so annuals. He knows the plane and when I met him to visit his shop I was suitably impressed. The engine is at 2300 smoh but has been flown regularly and had oil analysis done every 50 hours. He's a proponent of continuing to run it like that as long as I continue the monitoring (will be day, VFR, over flat land, since I'm a chicken ex-airline pilot). I've got a couple A and P's I trust but they don't know the airplane. This guy is probably on the higher end compared to the others but I'm going to give it a shot. This shop is a four hour drive from where I'll be living soon and I have a friend in my new town who is a very well regarded IA. It was a tough call but in the end I thought it would be good to keep the plane with the guy who did the last five annuals even if it costs a bit more. Will probably switch to the local mechanic after that. Thoughts on running an engine past TBO if it's flown regularly, oil analysis, oil change and check the screen every 50 hours, and check compressions every 50 hours?
Eagle421flyer
Well-Known Member
What is TBO on that engine? Is the engine TBO is 2000, or is it 1600? Makes a difference as to how much further one is expecting components to last. Has any mechanic been into the power plant with a good borescope it might give you a general idea of the health and if there is corrosion.
Bottom line engines are expensive. It sounds like everything is being done to ensure reliability on a past TBO engine. One thing you have going for you is this is not a turbo charged/high power engine, however failures can occur that could do severe engine damage, thus necessitating a bigger expense down the line. There is a reason for TBO limits from the manufacturer; this limit gives you a reasonable time frame for reliability. With that being said I had an engine fail on me after 100 hours, but that was due to a bearing failure. If you have an engine overhaul shop that you trust, or other mechanics that you know well, I would run the question around the room. During an engine overhaul, there can be many serviceable parts, such as the crankshaft, crankcase, cam shaft, that all get put back in during a rebuild. Parts such as bearings, pistons, cylinders, and valves are worn out and not used again by the time the engine makes it to TBO, and at this point in your engine, are probably not as healthy as say your crankshaft. The other question is how many overhauls has that engine gone through? If major components were replaced last time (ie crankshaft), they could be good for several more overhauls. But if a part like your crankshaft is older, it could be out of limits now even though the engine is still performing well, until it does not perform at all. As in everything aviation, we try to control what we can, and deal with what we cannot as it comes up. Your question is a tough one for sure, a balance of cost vs reliability and monitoring the health of the engine through preventive measures. Bottom line, this answer comes down to having the best information you can find from experts, and then determining what you are comfortable with. Clear as mud? But I do understand the situation you face with your powerplant.
DE727UPS
Well-Known Member
I think it would be the 3rd overhaul, so good point on the crank. It's a stock O320E2A. 2000 hour TBO. I've talked to a few people who take these engines to 3000 without issue. I will be flying it day, VFR, in the relatively flat terrain of central and eastern WA. Pretty comfortable with that. Will make sure it's borescoped at the annual. Thanks for the input.
CFI A&P
Exploring the world one toilet at a time.
No issue with that strategy at all. Just remember the engine will talk to, and listen to what it has to say. Plenty of engines go well beyond TBO - both calendar and hours, as long as issues are addressed promptly. Mike Busch is a big advocate for just that. I think he ran his personal C310 to something like 3,000 or 4,000 hours between overhaul.
USMCmech
Well-Known Member
My 50 year old engine is 2100 hours SNEW and perfectly healthy and I have absolutely no plans to open it up.
DropTank
Well-Known Member
I'm not a believer in fate or karma but...
EIR
It's 5 o'clock somewhere
Are you implying that a perfectly good engine needs to be overhauled once it reaches TBO?
Inverted25
Well-Known Member
Mike Busch is the man. I have seen flight school planes here get to 2800 before starting to show signs of wear. The more often it’s flown the better it will be.
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killbilly
Vocals, Lyrics, Triangle, Washboard, Kittens
...don't fix what doesn't need fixing. Like the others said re: Mike Busch....if the engine is happy, compressions are good and you've got a good oil analysis program as an early-warning system, there's no reason to do a teardown/overhaul.
Especially at today's prices.
bimmerphile
Sidestick Wiggler
corrosion kills, I got a dehydrator since I live in a coastal area with high humidity and have a new engine. it pumps air thru a tub of silica pellets and dries it out before sending it into the case. hopefully keeps the cam from rusting as that seems to be the big killer on lyc motors since they arent submerged in oil
beyond that and regular oil analysis for preventative mx just fly it regularly and let er rip past overhaul if everything else checks out
beyond that and regular oil analysis for preventative mx just fly it regularly and let er rip past overhaul if everything else checks out
drunkenbeagle
Gang Member
I'm not an A&P, but own a plane with an O-320-E2C. I see no reason not to run it past TBO. Borescope every time you pull the plugs, do the oil analysis. Make sure it is leaned enough. I have CHT/EGT on each cylinder, which you really want to have. You want to change the oil every 4 months even if you haven't hit 50 hours. Try to make sure it flies at least once a week. What I wouldn't run past TBO are the mags - you really do want to IRAN or overhaul those on schedule.
killbilly
Vocals, Lyrics, Triangle, Washboard, Kittens
I toyed with the idea of one of those. MD is kinda humid and you've seen the hangar...it barely qualifies as a physical structure out there....where'd you get yours?
On the other hand, I DID have one of the pre-heaters from AntiSplat installed and that thing is the cat's pajamas. Gets the oil considerably warmed up fairly quickly.
