The day has finally come....

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neilw2

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That day that every plane owner wakes up in a cold sweat thinking about around annual time....

It's the day the A&P says I have to start thinking about a engine overhaul.

I have been having to replace cylinders on my O-470U frequently recently (almost each of the last 3 annuals) and now he showed me where there is wear on the lifters.

Engine only has 850 SMOH but that overhaul was done in the mid 90s, so it's a very low used engine since before I started flying it 3 years ago.

So now I'm in the market for an overhaul- YAY!! (that is of course if I can convince my partners not to just sell the plane and my wife not to divorce me :D).

From speaking with my mechanic the delta between a overhaul and just purchasing a TCM rebuilt is very low (34k from TCM direct vs. 32k from Pen-Yan), and it makes more since from downtime and resale perspective just to get one direct. Does that make since?

Do anybody know of a good, reputable overhaul shop with significantly lower prices than what I was quoted from Pen-Yan?

Is my reasoning of just getting a factory OH 0 time make since?

Any good whisky recommendations that I can drown my sorrows with kissing this $ goodbye?
 
Oh, one other thing.

neilw2 said:
Any good whisky recommendations that I can drown my sorrows with kissing this $ goodbye?
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My wife would kick me in the nads if I bought a bottle of whisky after telling her it was time to overhaul an engine! :eek:
 
Banjo33 said:
Oh, one other thing.





My wife would kick me in the nads if I bought a bottle of whisky after telling her it was time to overhaul an engine! :eek:
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So your saying something cheap then? Like this?
poland-spring-vodka-poland-10143235t.jpg


Full disclosure: I once drank this in college, I remember the first 1 going down ROUGH...don't remember much else that night...
 
Banjo33 said:
No, but sense makes “since”! Sorry, couldn’t help myself, lol. Good luck and also really sorry to hear it’s “that time” for you!
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Thanks, what I could use is a good kick in the pants right now :D haha
 
I avoid factory exchange re-mans/rebuilts, as they have a blend of parts from many many different used engines. Not unlikely to get 1/2 an engine case with 8,000 hrs, the other half with 3000 hrs for example.

Many A/C buyers prefer a quality overhaul from a well known engine shop to "like new" condition, or a factory new engine. My O-470-R costs about $28K for a high end shop O/H to like new and 2-3 year warranty. Factory new Conti is $34K with core exchange.

Your "Core" would be broken down ,cleaned, inspected, and put into a parts pile with all the other cores. That's the group of mixed parts that make-up the factory off the shelf re-mans.

(next 10 posts are guys who love factory exchanged re-mans.)
 
Have you considered disassembling the engine and fixing what is wrong with it rather than throwing the whole thing away? Depending on what you find wrong your best option may be an engine overhaul but it doesn't seem like you've built enough evidence to pull the plug on it just yet.
 
NordicDave said:
I avoid factory exchange re-mans/rebuilts, as they have a blend of parts from many many different used engines. Not unlikely to get 1/2 an engine case with 8,000 hrs, the other half with 3000 hrs for example.

Many A/C buyers prefer a quality overhaul from a well known engine shop to "like new" condition, or a factory new engine. My O-470-R costs about $28K for a high end shop O/H to like new and 2-3 year warranty. Factory new Conti is $34K with core exchange.

Your "Core" would be broken down ,cleaned, inspected, and put into a parts pile with all the other cores. That's the group of mixed parts that make-up the factory off the shelf re-mans.

(next 10 posts are guys who love factory exchanged re-mans.)
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why would you care how many hours are on the parts?....they dimensionally meet spec, right? Plus, there's good science that says that high time parts are better than new....because they have a proven history and are well beyond the infant failure stage.
 
Checkout_my_Six said:
why would you care how many hours are on the parts?....they dimensionally meet spec, right? Plus, there's good science that says that high time parts are better than new....because they have a proven history and are well beyond the infant failure stage.
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Metal fatigue. There is a reason some parts are life limited.
 
If you had 3 completed engines to pick from, and one had half an engine case with 8,000 hours and the others had 1500 hrs.... which one would you buy?

The factories are under no obligation to inform you of component age in factory exchange Re-mans.
 
NordicDave said:
If you had 3 completed engines to pick from, and one had half an engine case with 8,000 hours and the others had 1500 hrs.... which one would you buy?

The factories are under no obligation to inform you of component age in factory exchange Re-mans.
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Do case halves " wear out" with time?
 
You could save a lot of money by tearing down the engine your self and sending the parts out for inspection then just have a good shop put the engine back together and hang it on the airplane. That is provided they don't find too many things out of specification.
 
NordicDave said:
If you had 3 completed engines to pick from, and one had half an engine case with 8,000 hours and the others had 1500 hrs.... which one would you buy?

The factories are under no obligation to inform you of component age in factory exchange Re-mans.
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In a reman, the Continental and Lycoming both throw out all accessories which are part of the engine package. It is generally cheaper for them to get new accessories then spend the labor to overhaul the,

Tim
 
Grum.Man said:
You could save a lot of money by tearing down the engine your self and sending the parts out for inspection then just have a good shop put the engine back together and hang it on the airplane. That is provided they don't find too many things out of specification.
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You’ll still save money in that scenario, compared to having someone else tear down the engine and tell you the same thing. And you’ll have a much better idea of the condition of your engine.

Honestly, if I hadn’t done mine myself I would have either thought I was getting robbed blind (if they replaced everything that really did need it) or would not have nearly as good an engine (if they didn’t replace the things I decided to replace)

It’s not for the faint of heart, but I still recommend doing it if you have even the slightest interest. The paperwork is daunting though. You’ll have nightmares about SBs by the time you’re done.
 
NordicDave said:
Yes. Cases get fatigued.
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Not often, more common is case design has changed to address issues. Such as thicker walls, changed bearing sizes (speculation is that lighter props do not have as much inertia causing more stress on bearings).....

Tim
 
Allow a 'little' extra for things not included in the overhaul/rebuild/new engine. They add up substantially. Could make a lengthy list here.
 
neilw2 said:
I have been having to replace cylinders on my O-470U frequently recently (almost each of the last 3 annuals) and now he showed me where there is wear on the lifters.
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Reference the lifters, my understanding of 470's is that the lifters are very easy to change and relatively cheap to do so. Of course this is providing the lifters haven't damaged the cam lobes.

I have nothing to add about the cylinder issue but am curious as to why you've been replacing them?

I am not trying to second guess your decision to O/H and wish you the best of luck during that! Just curious how people come to their final decision to O/H as that will obviously be one (or two) I have to make one day.
 
Pull all the lifters and inspect have someone who knows what they are looking at inspect the cam lobes. Tappets usually fail first so there is a possibility the lobes are good and new tappets could save it?FWIW crankcases are machined as a matched set during manufacture. Swapping 1/2 a case is just not done. Aluminum cases fret. I have never seen or heard of fatigue in a case.
 
Once again @charlie proves that he's a man of honor and integrity who participates here to assist the masses and not simply to line his own pockets like some other "professional" members (who shall remain nameless) do.

Thanks Charlie.

And it's not just here. I've read Charlie's posts on numerous sites over the years and that has consistently been his approach.
 
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Checkout_my_Six said:
name the part.....my experience is that's not common with steel parts..
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My engine is the original from 1965. It was overhauled by Zephyr in 1998, so the next time would be the third run. It has 1100ish hours right now. It's too old for a trade. You don't think the case is any more prone to issues than a case half its age? I'm just weighing my options when my time comes.
 
Look on the top of the backbone for stamping WDC and 4 numbers. If that is there the case was lap and align bored and probably had cracks repaired. If that is the case there is a somewhat greater chance that it will reject. Most cases will survive two overhauls and I've seen some with three sets of numbers. That being an original 1965 engine it will be a narrow deck case which is less prone to cracking than the wide decks. Since the factory won't take it as a core your options are limited to which overhaul shop you want to deal with. Charlie Melot
 
rbridges said:
My engine is the original from 1965. It was overhauled by Zephyr in 1998, so the next time would be the third run. It has 1100ish hours right now. It's too old for a trade. You don't think the case is any more prone to issues than a case half its age? I'm just weighing my options when my time comes.
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I'd send it to Zephyr and let them tell ya. It could be fine. Plus, how long you gonna keep it? You think you'll run another 2,000 hrs thru it? I bet not.
 
Checkout_my_Six said:
I'd send it to Zephyr and let them tell ya. It could be fine. Plus, how long you gonna keep it? You think you'll run another 2,000 hrs thru it? I bet not.
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Believe me, I've done the math. If the plane gets another 2000 hrs, I'll be a distant memory. I just don't want it to spring a leak 200 hours into an overhaul. I figured I'd send it back to them when the time comes, but I was just trying to brace myself for realistic options when that happens.
 
neilw2 said:
I have been having to replace cylinders on my O-470U frequently recently (almost each of the last 3 annuals) and now he showed me where there is wear on the lifters.
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Explain how he did that...?
 
Checkout_my_Six said:
why would you care how many hours are on the parts?....they dimensionally meet spec, right? Plus, there's good science that says that high time parts are better than new....because they have a proven history and are well beyond the infant failure stage.
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Simply because the more hours the bigger chance that they will have been overhauled before (many times) and probably won't pass the size requirements to be used again.
 
GRG55 said:
Do case halves " wear out" with time?
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No, but in some cases the case can only be lapped and line bored a certain number of times until the deck hight is out of limits.
 
Tom-D said:
Simply because the more hours the bigger chance that they will have been overhauled before (many times) and probably won't pass the size requirements to be used again.
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unless yer buyn factory new....you’ll have no idea what’s on that zero timed bucket of bolts.
 
I find it interesting when reviewing an airplane these days, in some instances there are more potentially applicable ADs for the engine and accessories (crankshaft retirements, cylinders that have to be junked, oil pump impellers, piston pins, oil filter converter plates, carb modifications and on it goes), than there are for the aging airframe.
 
Checkout_my_Six said:
unless yer buyn factory new....you’ll have no idea what’s on that zero timed bucket of bolts.
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This is true, but time on the engine you are having overhauled is a big factor on what you should do with it.
 
Anyone believe it is nice to know what was done on the last overhaul?
 
Tom-D said:
Anyone believe it is nice to know what was done on the last overhaul?
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I have a notebook an inch thick with the records of what I did to mine. Every process, every part number, every serial number for the parts big enough to have them. Far better documented than you'd get if you sent it out to have it done.
 
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