76 182P O-470 Lifter and Cam Corrosion Concern

[RussW]

Im getting a pre-buy done on a 76 182P with a factory reman installed in 2007. Currently has 398 hours since rebuild. Up until 2013 it was flown about about 50-60 hours a year, about 20 hours in 2014 and only about 10-15 hours a year since then. Plane is very clean, well kept, no damage, complete logs, good compressions, cylinders and valves look clean, always annualed on-time and babied… just not flow a lot in the past 5 years or so. Pre-buy A&P put a borescope down the oil filler and took these shots of the front couple of lifters and cam lobes and saw what he categorized as light/mild corrosion. He suggests pulling all lifters to get a better look at them and the cam lobes as well.

Should I run from this one? Should I let him pull all the lifters? If he finds nothing more that what you see here, continue with purchase? Put in new lifters and leave the cam as-is for now? Renegotiate down some to help offset what may be an early rebuild? Thoughts and opinions appreciated and welcomed!

Many Thanks!

Russ - Pearland, TX

 

[Clip4]

From what I see there I would be quite concerned, I would call a couple engine shops and ask to send those photos to them for their opinion on severity and suggestions.

 

[alfadog]

Personally, I would negotiate the price down, fly the airplane, and keep an eye on the issue. I think you have a good idea of what is going on (fairly light, IMO, pitting corrosion) and would not bother pulling the lifters.

 

[Stewartb]

I'd like to see pictures from a couple of similar total time "healthy" engines to compare. These pics don't mean much without a baseline. That engine isn't new and it doesn't look like some I've seen disassembled. It's somewhere in the middle. It would be nice to establish what the middle looks like in other engines before judging this one. I'm not sure I want to see what the inside of mine looks like!

 

[benyflyguy]

Is that corrosion from just nonuse???

 

[RussW]

Is that corrosion from just nonuse???

I think it is... as I mentioned, it’s only been flown 10-15 hours a year for the past 5 or so years. Although the owner is very meticulous about everything from waxing, annuals, etc., my guess is lack of regular use may be the culprit here.

 

[Let'sgoflying!]

I would be concerned.
Those lifters could be on the downhill slide and you might be looking at a teardown soon.
Frankly, I'd be changing those lifters.
I would have to discount any offered price from that of the same airplane without such images. It's also hard to tell what shape the lobe surface is without touching it.
CM has a SB on assessing cam lobes and lifters.

 

[mondtster]

This is a big Continental, not a typical Lycoming. If the owner will allow it I’d pull the lifters and have a look. If the lifters are pitted but the cam looks ok I’d put lifters in it and move on. What I wouldn’t do is run the engine a bunch until you know, otherwise you might be putting a cam in it too.

Be glad things are looking as good as they do. I just opened up another 600 hour Lycoming that needs a cam and lifters. It never seems to end...

 

[Salty]

This is a big Continental, not a typical Lycoming. If the owner will allow it I’d pull the lifters and have a look. If the lifters are pitted but the cam looks ok I’d put lifters in it and move on. What I wouldn’t do is run the engine a bunch until you know, otherwise you might be putting a cam in it too.

Be glad things are looking as good as they do. I just opened up another 600 hour Lycoming that needs a cam and lifters. It never seems to end...

This.

Those lifters will grind down the cam lobes quickly.

 

[Let'sgoflying!]

SID05-1B

 

[Raymo]

Looks like pitting to me. Do as your A&P recommends. If the owner won't allow it, walk away.

 

[FlySince9]

Looks like pitting to me. Do as your A&P recommends. If the owner won't allow it, walk away.

Yea that would be my first question. Because if the owner isn’t in to that, it’s moot.

 

[Stewartb]

My advice? Establish what the airplane value is to you and make an offer. No emotion, just business. The seller may reject it or choose to negotiate. If he rejects it he still may come around at some point in the future. What it’s worth to him has nothing to do with what it’s worth to you.

 

[Dan Thomas]

SID05-1B

A paragraph from that SB:

Distress issues can be reduced by sustaining frequent flight operations under normal oil
temperatures. A minimum 30 minute cruise flight is required (oil temperatures are stable at
170°F to 200°F range). This function assists the removal of moisture and acids from the
system. As a result of such frequent operation, fleet operators rarely experience excessive
corrosion or distress.

I have seen far too many engines suffer internal corrosion because their owners ground-run them instead of flying them. If you are going to ground-run it, thinking that you're circulating the oil and doing the engine a favor, you might as well burn a stack of $100 bills to preheat it. Cold engines have large clearances that let a lot of blowby gases into the crankcase, and water vapor is a major component of those gases, along with corrosive byproducts of combustion. That water mixes with the oil and forms acids, the reaction being catalyzed by the metals, and the acids eat the engine. An engine shut down after a good flight, then left to sit for years, will often be fine inside.

Atmospheric moisture is a very minor player here. There have been other threads on this subject, and some posters have calculated the amount of water that could be carried into crankcases and fuel tanks due to environmental thermal cycles, and even with very wet air the amounts are tiny.

 

[brien23]

This.

Those lifters will grind down the cam lobes quickly.

If you buy it tear it down you might be able to grind the cam to save it and replace other items now, if not the metal from the cam lobes grinding down will get real expensive fast. Unless you get a real good deal on the plane look for another this one could cost you more in the long run than you think.

 

[charlie]

If you can buy it knowing where $10K is coming from if the cam goes buy it. If the rest of the cam is no worse than shone here put in new lifters and hope for the best. Charlie Melot