Pitting cylinders

I

ivan.rosado1

Filing Flight Plan
Joined
Jul 22, 2015
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I'm looking to buy a 1981 piper archer II. Looking at the logbooks I read that at the last annual, the mechanic found light to moderate pitting on the cylinders. I am wondering if this is an early sign of problems or is it to be expected. Aircraft is around 3000 TTAF and about 600+ since major.
 
ivan.rosado1 said:
I'm looking to buy a 1981 piper archer II. Looking at the logbooks I read that at the last annual, the mechanic found light to moderate pitting on the cylinders. I am wondering if this is an early sign of problems or is it to be expected. Aircraft is around 3000 TTAF and about 600+ since major.
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How long (calendar time) since major? I'm no expert, but corrosion (what I suspect the pitting is from) is more likely in an engine that sits for long periods.

John
 
Where is the airplane located?

Light to moderate pitting at 600 hrs sounds like it has been sitting/not flying in a wet climate. I would not expect it to make TBO without cylinder work in the not too distant future. Is the asking price accounting for this?

The next question I would have is, if the cylinders are showing that at 600 hrs, what is the condition of the rest of the airframe?

This might be an airplane to get a good deal on with the expectation that you are going to have to put money into it or it might be one to run away from.

Just my thoughts as an pilot and owner. I'm not an mechanic.
 
ivan.rosado1 said:
I'm looking to buy a 1981 piper archer II. Looking at the logbooks I read that at the last annual, the mechanic found light to moderate pitting on the cylinders. I am wondering if this is an early sign of problems or is it to be expected. Aircraft is around 3000 TTAF and about 600+ since major.
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ON the cylinders?
 
The Aircraft is in FL. I am waiting on the info about the last overhaul. Your feedback sounds exactly what I am suspecting. Price sounds right (close to vref) but my "mission" does not include hiring a full time mechanic (LOL). Jokes aside, I want this archer to get my instrument rating and do some island hoping with my wife and son (I live in Puerto Rico). A project plane sound like fun but not right now.
 
External corrosion is an indication of not painting the cylinders. Not much else.
 
If corrosion damage is observed inside 600 hour cylinders that have used 100LL I'd be concerned about corrosion on the parts I can't see. With the little info provided all I'd say is it warrants looking closer.
 
With the glut of used airplanes available, why would anyone even consider one in Florida?
 
Karl, off topic. I followed your old 185 into Hood on Sunday. It got some exercise this week. :)
 
ivan.rosado1 said:
I'm looking to buy a 1981 piper archer II. Looking at the logbooks I read that at the last annual, the mechanic found light to moderate pitting on the cylinders. I am wondering if this is an early sign of problems or is it to be expected. Aircraft is around 3000 TTAF and about 600+ since major.
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How much has it flown in the past 6 months?
 
Stewartb said:
Karl, off topic. I followed your old 185 into Hood on Sunday. It got some exercise this week. :)
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I hope it is still in the immaculate shape it was in when it flew away. I miss that airplane, titanium gear and all!!!

Eq2ZvBvb_ddLsNVp-tSYeoehvBWfmrWb6qMiGPk_d5Ym=w908-h681-no
 
ivan.rosado1 said:
The Aircraft is in FL. I am waiting on the info about the last overhaul. Your feedback sounds exactly what I am suspecting. Price sounds right (close to vref) but my "mission" does not include hiring a full time mechanic (LOL). Jokes aside, I want this archer to get my instrument rating and do some island hoping with my wife and son (I live in Puerto Rico). A project plane sound like fun but not right now.
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have you priced out what hangar and insurance is gonna set you back every year basing it in PR? For a 4 banger spam can you may be putting the cart ahead of the horse here. Island climates ruin these airplanes in short order.
 
ivan.rosado1 said:
The Aircraft is in FL. I am waiting on the info about the last overhaul. Your feedback sounds exactly what I am suspecting. Price sounds right (close to vref) but my "mission" does not include hiring a full time mechanic (LOL). Jokes aside, I want this archer to get my instrument rating and do some island hoping with my wife and son (I live in Puerto Rico). A project plane sound like fun but not right now.
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N Florida or South Fla? This is an "eyes on" call. It could be fine, it could be the tip of the corrosion iceberg, you have to see the whole package to tell, and it takes a few minutes in person typically to know to walk away. If it's at a SE Fla airport I can swing by and take a peak.
 
Not all of Florida is coastal. Yeah, a lot of it is, but mine was in Live Oak - so the salty air wasn't an issue. No corrosion anywhere, and it sat for a while before I picked it up.
 
EdFred said:
Not all of Florida is coastal. Yeah, a lot of it is, but mine was in Live Oak - so the salty air wasn't an issue. No corrosion anywhere, and it sat for a while before I picked it up.
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When I first moved to Florida I moved into a house a hundred yards from the ocean. As I always did in Georgia, I left all my tools in the garage. After a year they were mostly unrecognizable through the rust and corrosion. And NONE of the power tools worked. If the motors turned at all they screeched the whole time. It sucked giving away the radial arm saw and the table saw.

Then I bought a house about 3 miles inland from the beach. In 15 years there is no corrosion on any of my garage kept items.

Three miles over (by the coast), an air conditioner has a life expectancy of about 3 years. Mine is 10 years old and still looks new. The only reason I replaced the 10 year old unit back then was to go from an 8 seer to an 18 seer unit.
 
Even coastal planes can be ok if properly cared for. Also I wouldn't neglect that care just because I was a few miles inland, and even in a hangar. If I had a nice Bonanza anywhere in FL, it would receive a corrosion inhibitor treatment when opened up each annual as part of routine service.
 
hindsight2020 said:
have you priced out what hangar and insurance is gonna set you back every year basing it in PR? For a 4 banger spam can you may be putting the cart ahead of the horse here. Island climates ruin these airplanes in short order.
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Yeah, everything is expensive here. I won't even talk about maintenance, we have a very limited supply of good shops so just imagine... Actually, hangar and insurance is the least expensive in the equation.
 
Tom-D said:
How much has it flown in the past 6 months?
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Very little. My estimate is about 50 hrs in the last year. I also noticed that on the last annual compression on two of the cylinders were 64. A&P signed of on it as airworthy.....

I consulted a local A&P and he says it should not be a problem but I should be prepared to have those cylinders overhauled at some point. It seems reasonable but I a still trying to get an idea of how much would that cost and make some adjustment in price.
 
ivan.rosado1 said:
I also noticed that on the last annual compression on two of the cylinders were 64. A&P signed of on it as airworthy.....
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Probably is perfectly airworthy at 64. But it is another sign that it probably won't make it to TBO without cylinder work.
 
ivan.rosado1 said:
Very little. My estimate is about 50 hrs in the last year. I also noticed that on the last annual compression on two of the cylinders were 64. A&P signed of on it as airworthy.....

I consulted a local A&P and he says it should not be a problem but I should be prepared to have those cylinders overhauled at some point. It seems reasonable but I a still trying to get an idea of how much would that cost and make some adjustment in price.
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I agree with your A&P. if anything were to happen from the pits, it would have happened by now. the pits will fill with carbon and the oil consumption will stabilize. run it until you have reason to do a repair.
 
Fearless Tower said:
Probably is perfectly airworthy at 64. But it is another sign that it probably won't make it to TBO without cylinder work.
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A little pitting won't necessarily shorten TBO. If you look at old engines, especially burnish cylinder ones, you'll see how poor the surface can be and still function just fine. Pitting on steel cylinders will self polish with chrome rings. As long as it doesn't get bad enough that it cracks a ring, it'll for the most part just increase oil consumption some. I've pulled off some ugly cylinders that were still working just fine. Also a fair bit can be addressed easily with a simple hone.

The big issue with cylinders is carbon and lead deposits on the exhaust valve and stem. Burned valves are the out of service cylinder defects.

If the engine is running 50 hrs a year, and starts and runs fine now, I would not use some cylinder pitting to reject a deal on a plane that is otherwise an 8+. I would inspect the rest of the plane carefully for corrosion though, and signs of corrosion treatments.
 
Fearless Tower said:
Probably is perfectly airworthy at 64. But it is another sign that it probably won't make it to TBO without cylinder work.
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I'd probably pull the cylinders now and do the cheap fix rather than wait until I have to buy a new cylinder.
 
Tom-D said:
I'd probably pull the cylinders now and do the cheap fix rather than wait until I have to buy a new cylinder.
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It's a 0-360 Lyc......,,

You can buy new cylinders for just a little more then rebuilt ones... And,,, I am not sure there are any more good cylinder shops left I would trust.. IMHO...
 
N801BH said:
It's a 0-360 Lyc......,,

You can buy new cylinders for just a little more then rebuilt ones... And,,, I am not sure there are any more good cylinder shops left I would trust.. IMHO...
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A ball hone would clean it up at this point, and it gives a chance to clean and lap the valves. Go back together with the same rings and your cost is a few bucks in cleaners/compounds, the ball hone, and the labor, add a 1/2" chuck drill if you don't already have one. As long as the valve guides aren't so worn they fail the wobble test, you can just clean it all up and put it back together.

It's really the lead that's the problem, it glues the carbon onto the valve and stem. Getting rid of leaded fuel will lead to considerable economic savings in cylinders in the average plane's life, especially HP engines run hot and rich. That's where you see everyone getting topped at mid time. LOP usually gets cylinders to TBO.
 
Henning said:
A ball hone would clean it up at this point, and it gives a chance to clean and lap the valves. Go back together with the same rings and your cost is a few bucks in cleaners/compounds, the ball hone, and the labor, add a 1/2" chuck drill if you don't already have one. As long as the valve guides aren't so worn they fail the wobble test, you can just clean it all up and put it back together.

It's really the lead that's the problem, it glues the carbon onto the valve and stem. Getting rid of leaded fuel will lead to considerable economic savings in cylinders in the average plane's life, especially HP engines run hot and rich. That's where you see everyone getting topped at mid time. LOP usually gets cylinders to TBO.
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I agree, that probably would work and at least answer the question of how bad is the pitting... BUT.. Most A&P's /IA's will insist on yellow tags for reconditioned cylinders nowadays....
 
N801BH said:
I agree, that probably would work and at least answer the question of how bad is the pitting... BUT.. Most A&P's /IA's will insist on yellow tags for reconditioned cylinders nowadays....
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I haven't found that true. I find enough among them very open to repairing things and even me supplying owner produced parts.
 
Henning said:
A little pitting won't necessarily shorten TBO
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OP said light to moderate pitting at 600 SMOH. He also said owner is asking VREF which probably doesn't account for that tidbit. OP also indicated he isn't looking for a project airplane or one that he'll need to sink money into after buying it.

And it's an Archer. There's 39 on TAP now.

I don't think this one is worth the additional time to do the due diligence. When you are looking at common airframes, you need to narrow the playing field down somehow.
 
N801BH said:
It's a 0-360 Lyc......,,

You can buy new cylinders for just a little more then rebuilt ones... And,,, I am not sure there are any more good cylinder shops left I would trust.. IMHO...
Click to expand...

Why would it take a good cylinder shop to remove the cylinders brush hone them and replace the rings. and maybe lap the valves?

You'd certainly make TBO that way.
 
Henning said:
Exactly, it would be silly of me to ask someone to pay for my due diligence.
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And what will you do when it is all apart on the shop floor and nothing is serviceable?

Prior to you tearing it down, it was flyable, but now you caused it to become unairworthy. are you willing to make the seller whole again?
 
Tom-D said:
And what will you do when it is all apart on the shop floor and nothing is serviceable?

Prior to you tearing it down, it was flyable, but now you caused it to become unairworthy. are you willing to make the seller whole again?
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No, it gets bolted back together. It wasn't airworthy before, it was misrepresented as airworthy.
 
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