Engine boroscope

[rturbett]

So- hoping my first attempt at posting these pictures works. Just received these as part of an annual.

Any red flags?

approximately 200 hours on the engine.

Thanks,

Rob

[MikeOH]

CAUTION: I am NOT an A&P so the following is ONLY my OPINION as an owner of a '70 M20F that has his own borescope and uses it regularly (every oil change)

1) Exhaust valves look good; even symmetrical patterns.  I would have liked better organization and full views of each exhaust valve in each cylinder.  But if those pictures cover all exhaust valves I think you are fine.

2) Seems some mild scoring, but not awful.

3) Looks like missing plating?? I've never seen that look in any of my cylinders.

For an engine with only 200 hours item 2 is kind of surprising, but if 3 is really missing plating that is kind of shocking on a 200 hour engine.

How long ago was the overhaul? (I.e. has the engine sat for a long time since the OH)

If you're not burning excessive oil/fouling plugs I don't think there's too much concern.

What does your A&P think about the condition?

[redbaron1982]

I'm not an expert. I'm a fairly new owner and have been boroscoping my engine every time I take out a spark plug. 

My main concern with your pictures is that there seems to be some corrosion/pitting on the cylinder walls. 

Do you know if the engine had some lengthy periods of time without running?

Edited November 2, 2023 by redbaron1982

[rturbett]

Thanks for the input-

I'm not qualified to have an opinion, so rather than blindly accepting the guidance of the inspector, I wanted to see what the group has to say.

Engine rebuilt in 2020, has 200 hours on it since. Was told it was flown regularly, and have no reason to question that.   

 

The report says  "The pictures show some corrosion but all within limits and is not effecting the compression at all. Manufacturers agree that this little amount of corrosion is fine as long as the compression checks are within limits"   

I'll have more info as we  move through this annual. I'm pretty excited. Looking forward to being more than just an armchair member of this group!

Rob

 

 

[EricJ]

1 hour ago, rturbett said:

Thanks for the input-

I'm not qualified to have an opinion, so rather than blindly accepting the guidance of the inspector, I wanted to see what the group has to say.

Engine rebuilt in 2020, has 200 hours on it since. Was told it was flown regularly, and have no reason to question that.   

 

The report says  "The pictures show some corrosion but all within limits and is not effecting the compression at all. Manufacturers agree that this little amount of corrosion is fine as long as the compression checks are within limits"   

I'll have more info as we  move through this annual. I'm pretty excited. Looking forward to being more than just an armchair member of this group!

Rob

I think that's a good assessment.    If the compressions are good, it's not using too much oil, and it's running fine and making static power, there's not much reason to worry.    I'd send in oil samples for analysis after oil changes just to start tracking trends.   Cutting the oil filter to check for metal is always a good idea.    Those can let you know early if or when problems start.

Except for the little bit of funkiness in the cylinder walls, those pics look great.  

[PT20J]

We now have so many tools such as engine monitors, oil analysis, borescopes, that we see things in this 80 year-old technology that were probably always there, but we didn't know about before, and so it is difficult to know what is normal. Exhaust valve distress is pretty easy to see, but what does some pitting or cylinder scratches portend? Lycoming told me not to worry about scratches where you can see the cross hatching through them because they are superficial and normal and don't hurt anything. If you can catch a scratch with a sharp pick then it might be a problem. Will a broken ring always scratch a cylinder? I don't know. If you notice an increase in superficial scratches, is that a problem, or will a broken ring always make a deep scratch? A little corrosion probably just increases oil consumption somewhat. But, how much corrosion is too much?

I just got an email from Savvy announcing that it is launching a borescope analysis product. Maybe someone will come along and give us a sample of what we might expect.

Skip

[hammdo]

@kortopates?

-Don

[kortopates]

1 hour ago, hammdo said:

@kortopates?

-Don

After 15 years, Savvy is re-aligning its service tiers that will go into effect very soon next year. For our Savvy Analysis clients the service is being expanded to now include both Borescope analysis as well as Savvy Breakdown. Prices will also go up, the first time in 15 years.  Associated with the Borescope analysis will be a format for submitting borescope picts that is in process right now. Clients are being notified over the next couple of weeks of the details and Savvy Pro clients will be offered a renewal discount from the price increase.

https://mailchi.mp/savvyaviation.com/limited-time-offer-50-discount-on-savvyanalysis-pro-890450?e=710336d60c

Edited November 2, 2023 by kortopates

[PT20J]

1 hour ago, kortopates said:

After 15 years, Savvy is re-aligning its service tiers that will go into effect very soon next year. For our Savvy Analysis clients the service is being expanded to now include both Borescope analysis as well as Savvy Breakdown. Prices will also go up, the first time in 15 years.  Associated with the Borescope analysis will be a format for submitting borescope picts that is in process right now. Clients are being notified over the next couple of weeks of the details and Savvy Pro clients will be offered a renewal discount from the price increase.

https://mailchi.mp/savvyaviation.com/limited-time-offer-50-discount-on-savvyanalysis-pro-890450?e=710336d60c

Thanks Paul -- that is clearer than the email.

But the devil is in the details. Would we be getting some sort of commentary on pictures submitted (sort of like Blackstone does with oil samples) or some blanket statement that the cylinders look about average for your cohort? The problem is that we need to learn something about how to interpret these pictures. I think everyone is pretty clear on exhaust valve heads. But what about deposits on the back side? What's normal? And how do we get good pictures of cylinder walls? I find it difficult because the walls reflect so much light that there is a lot of glare and it screws up the autofocus. How do we know for sure the difference between a scuff and an oil smear? How much scoring is normal? Lycoming piston pin plugs are suppose to rub on the cylinder walls, but how much burnishing is normal? 

So, for instance, what would you have to say about the OP's pictures? I think most of us that responded admitted that we really don't know a lot about interpreting these things.

Skip

[rturbett]

It seems to me that an education photo guide would be very valuable- I keep thinking back to the Chiltons auto repair guide that had a series of photos of spark plugs each showing different problems. Photos of valves, cylinder walls, cylinder heads in different states of distress and age, compared to "normal for each stage.

 

something like this that is used for Autos