Doing the top

[dogman]

Back in July I wrote about our Ch. Six using more oil than it should. Through discussions here we decided to just to change out #3 cylinder for falling Compression. Changed number three. It is still burning a quart every 5 to 6 hrs.
The Compression was GOOD an all others. Then the sound of clattering as I would lean did appear. So I gave up ordered the remaining 5 New cylinder assemblies and 5 new piston pins. Yesterday My Mech took it apart. I went up today to see what he found. 1,5,4,2 bores were worn out from top to bottom. #6 broken ring, 1,4,6 had terrible wear on the piston pin caps. A new cap measures 1.125" some of the caps removed measured 1.080 tapered to 1.112. Can you say Clatter?? I am SOOOOOOOOOOO glad I decided to replace the rest.
The good news is that the cam and the bottom looks great so far. F.REMAN 1066hrs.

The other thing is that my gut feeling was correct, DO NOT MESS WITH THIS DO THE TOP. This was getting bad as the more these piston caps got wore the faster they would wear. I am guessing that I was getting close to a complete engine failure. Make me feel a little ill.

Dogman

 

[bbchien]

Back in July I wrote about our Ch. Six using more oil than it should. Through discussions here we decided to just to change out #3 cylinder for falling Compression. Changed number three. It is still burning a quart every 5 to 6 hrs.
The Compression was GOOD an all others. Then the sound of clattering as I would lean did appear. So I gave up ordered the remaining 5 New cylinder assemblies and 5 new piston pins. Yesterday My Mech took it apart. I went up today to see what he found. 1,5,4,2 bores were worn out from top to bottom. #6 broken ring, 1,4,6 had terrible wear on the piston pin caps. A new cap measures 1.125" some of the caps removed measured 1.080 tapered to 1.112. Can you say Clatter?? I am SOOOOOOOOOOO glad I decided to replace the rest.
The good news is that the cam and the bottom looks great so far. F.REMAN 1066hrs.

The other thing is that my gut feeling was correct, DO NOT MESS WITH THIS DO THE TOP. This was getting bad as the more these piston caps got wore the faster they would wear. I am guessing that I was getting close to a complete engine failure. Make me feel a little ill.

Dogman

What were you getting in your screen? And oil analyses?

 

[dogman]

I just acquired the Six in June there was no history of Metal in filter and there was none found in the two oil changes I have helped with.

Oil analysis?? There were no analysis being done that I know of. IF there had been It would have been very apparent that something was drastically wrong. In the two oil changes, I did not get it done. Not because I do not believe in it because I just didn't find the time to get it done. DUMB DUMB DUMB!!
You can bet that I will begin the oil analysis NOW.

Who do you use for oil analysis.

 

[Lance F]

I'm very happy with Blackstone Labs. They give you the data and a written analysis. Also very helpful on the phone.

 

[wsuffa]

Trend is more important than single sample.

Pick a lab and use it each time. They will usually give you a sample history for quick comparison.

 

[Let'sgoflying!]

None that I've seen are going to commit to 'your engine is fine'; most don't even provide normal ranges when they send the values back. Because of testing interval or the nature of failure it is quite possible to do a long series of 'non-abnormal' tests only to have an engine crater the day after. I still test, but it is only one of the tools and probably not a great one; I often think of dropping it.
I use AOA Aviation Oil Analysis but didn't someone say they were in NewOrleans?, anyway, I have no complaints about them.

 

[wsuffa]

Dave,

AOA is in Phoenix.

You're right, it's not the only thing you need to look at, but it is a datapoint.

I'm still surprised at the number of folks that don't bother to cut open the oil filter at each change.

 

[LauraH]

Our club uses Blackstone Labs for analysis. They are very responsive and helpful by e-mail also, in addition to by phone as LanceF stated. They give normals for the values for your engine, and also averages for your specific engine.

Laura Herrmann
Maintenance Director
Twin City Cloud Seven Flying Club
FCM, Eden Prairie, MN

 

[bbchien]

Well good on you, Dogman, for listening to your engine talk to you. They do talk. You just have to listen.

 

[jdwatson]

It's gotta be nice to know what to listen for and to listen to the same engine day after day. Renters, like myself, hear different engines almost everytime we fly. I find it interesting that of the 6 172s that each one sounds different.

 

[dogman]

It's gotta be nice to know what to listen for and to listen to the same engine day after day. Renters, like myself, hear different engines almost everytime we fly. I find it interesting that of the 6 172s that each one sounds different.

Yes, but you have the option of saying, "Holy Moly that does not sound right". Taxi back find FBO Manager you say " You had better spend $10k to get that fixed it sounds funny, I believe I will take the HMMMM Blue one."

 

[Henning]

It's gotta be nice to know what to listen for and to listen to the same engine day after day. Renters, like myself, hear different engines almost everytime we fly. I find it interesting that of the 6 172s that each one sounds different.

While each one may run at a unique note, there are common sounds of things going wrong, tock tock tock... being a prime example of a noise that should cancel a flight for further investigation, popping or stuttering when advancing the throttle is another one. An occasional missfire of one cylinder is not necessarily a cause for alarm, but a subsequent one is when you start checking your landing options more carefully. Some engines run 'rougher' than others primarily from a prop balance POV. If someone spent the money for a good dynamic balance job, you feel it, and it can also make a difference to your TBO and crank/case wear at overhaul. It really is a high value service.

 

[dogman]

. Some engines run 'rougher' than others primarily from a prop balance POV. If someone spent the money for a good dynamic balance job, you feel it, and it can also make a difference to your TBO and crank/case wear at overhaul. It really is a high value service.

So are there quite a few shops that do this Prop balance? Does any one know the normal cost for a 3 blade prop.

Yes the sounds that Make you take a deep breath and say a little prayer. Well may be big one.

 

[Henning]

So are there quite a few shops that do this Prop balance? Does any one know the normal cost for a 3 blade prop.

Yes the sounds that Make you take a deep breath and say a little prayer. Well may be big one.

Many shops contract this out to someone who specializes in it. Look in TAP, probably someone in your area is advertizing. I don't know the curent pricing, sorry, but you should be able to find it advertised, probably a few hundred dollars, rarely takes over an hour and doesn't involve much real work.

 

[dogman]

Many shops contract this out to someone who specializes in it. Look in TAP, probably someone in your area is advertizing. I don't know the curent pricing, sorry, but you should be able to find it advertised, probably a few hundred dollars, rarely takes over an hour and doesn't involve much real work.

THANKS .

Top is done Pick it up today. I have to go on a couple long trips now and get it broke in.

Can't wait to get it broke in and see if any difference in Performance.

 

[gkainz]

THANKS .

Top is done Pick it up today. I have to go on a couple long trips now and get it broke in.

Can't wait to get it broke in and see if any difference in Performance.

such an odd commonly used phrase "broke in" or "broken in" considering we're trying to avoid "broke" things in our aircraft, don't you think? Best of luck!!!

 

[dogman]

such an odd commonly used phrase "broke in" or "broken in" considering we're trying to avoid "broke" things in our aircraft, don't you think? Best of luck!!!

The opposit of BROKEN OUT! OR BROKEN DOWN!

Thanks for the luck.