IO-540 Rust

Green Hornet · Post by **Green Hornet** » Sat May 31, 2008 9:35 am

Paul,
I agree we must have pictures!

I sent you an email with the following link:

http://www.imageshack.us/

zuelke · Post by **zuelke** » Sat May 31, 2008 7:39 pm

if somebody wants photos - send me your email address and I will send them to you - I could not figure out the imageshack site

Green Hornet · Post by **Green Hornet** » Sun Jun 01, 2008 9:31 am

I am posting these photo's for Paul:

By sojorrn, shot with C5050Z at 2008-06-01

210TC · Post by **210TC** » Sun Jun 01, 2008 10:24 am

The only one I see clearly is the last photo.
I have seen this before. Piston was at bottom dead center and it appears moisture or something intered from the combustion chamber side not the crankcase side.
the two ring marks show the ring my have even stuck at one time as it clearly shows above and below ring corrosion. This would have taken longer than two weeks (my opinion)
This very well could have happened at the factory or in the field.
If this is and injected engine something could have enter through th e fuel system.
It is possible something happened during breakin at the factory.
It is possible this is not from H2O.
It is possible an unknown chemical caused this.
I'm not sure how lycoming assembles there engines. However, I do know some air cooled engine manufactures in Europe assemble the pistion with the rings installed into the cylinders in advance.
When it is time to place the barrel on they just use the wooden side of a hammer to bump the pistion down enough to insert the wrist pin into the rod (lyc would use a different method to pull the piston down). I brought this up to make the point that this corrorsion could have started before the engine was installed on the aircraft or after the engine was run in.
And this IS NOT FROM condensation (my opinion). Something puddled in the cylinder. If this is in the bottom of the cylinder it happened after assembly. If the corrosion is somewhere besides the bottom it happened while on the shelf and before the engine was assembled.
It is possible (but highly unlikely) moisture enter through the back side of the piston. This is the last ring (I think) and the last ring is the oil ring. The ring land cut into the piston (for the oil ring) has holes in it for oil to come and go.

Green Hornet · Post by **Green Hornet** » Sun Jun 01, 2008 11:00 am

Ring, ring, phone pause: a few more of Paul's engine:

By sojorrn, shot with C5050Z at 2008-06-01

Green Hornet · Post by **Green Hornet** » Sun Jun 01, 2008 11:10 am

210TC wrote:The only one I see clearly is the last photo.
I have seen this before. Piston was at bottom dead center and it appears moisture or something intered from the combustion chamber side not the crankcase side.
the two ring marks show the ring my have even stuck at one time as it clearly shows above and below ring corrosion. This would have taken longer than two weeks (my opinion)
This very well could have happened at the factory or in the field.
If this is and injected engine something could have enter through th e fuel system.
It is possible something happened during breakin at the factory.
It is possible this is not from H2O.
It is possible an unknown chemical caused this.
I'm not sure how lycoming assembles there engines. However, I do know some air cooled engine manufactures in Europe assemble the piston with the rings installed into the cylinders in advance.
When it is time to place the barrel on they just use the wooden side of a hammer to bump the piston down enough to insert the wrist pin into the rod (lyc would use a different method to pull the piston down). I brought this up to make the point that this corrosion could have started before the engine was installed on the aircraft or after the engine was run in.
And this IS NOT FROM condensation (my opinion). Something puddled in the cylinder. If this is in the bottom of the cylinder it happened after assembly. If the corrosion is somewhere besides the bottom it happened while on the shelf and before the engine was assembled.
It is possible (but highly unlikely) moisture enter through the back side of the piston. This is the last ring (I think) and the last ring is the oil ring. The ring land cut into the piston (for the oil ring) has holes in it for oil to come and go.

David,
When you say the only one you see clearly is the last photo. Do you mean the anomaly or the photo is fuzzy?
How are things?
Best Regards
Bill

210TC · Post by **210TC** » Sun Jun 01, 2008 11:43 am

I cannot see the corrosion on the cam, the picture is clear.
The additional photo's you posted show a different story than the first.
One cylinder got hot and is scored from piston skirt contact.
This is another reason to use regular compression testing instead of differntial compression testing. If the scoring has upset the ability of the rings to draw in air and compress that air it will show up.
In a differential test the piston remains at top dead center and will not give ANY indication of cylinder wall problems. Most cylinder wall problems do not occur at top dead center. Although it can.
In an overheat situation the skirt (bottom of piston) most likely makes wall contact first. In a more severe situation the top of the piston will expand to a point of contact with the cylinder wall. This will likely be caught by the pilot as a loss in power and an increase in oil consumpion and increased blow by (oil on the belly).

210TC · Post by **210TC** » Sun Jun 01, 2008 12:21 pm

When you see this you ask yourself "why did the oil analysis not detect some of these problems"?
Could be the sampling method. Could be the lab. Could be many things.
I only do testing on the first and second oil changes of a new engine. if things don't settle down I will do another. I will only use cat for my testing.
If something makes a change, oil pressure etc. I may consider another test.
Please do not follow my proceedures as it is clearly more favorable to test at every oil change.

BTW, the higher aluminum in his last test could be from the piston wall contact?

a64pilot · Post by **a64pilot** » Sun Jun 01, 2008 12:32 pm

From what I can see, it looks like honing the cylinders and fitting new rings is all that would be required. If I split the cases, then it's getting new bearings and new or reground cam and tappets, unless there is no wear at all.
Why nickel plate the cylinders? Isn't nickel plating very similar to chrome? I don't think as often as you fly that plated cylinders are warrantied, and I don't think you will like them. I don't like Chrome cylinders.

Green Hornet · Post by **Green Hornet** » Sun Jun 01, 2008 12:57 pm

Ignore This! I checked my notes from 30+ years ago and it was Au not Cu!:roll:
In the semiconductor industry we had an issue with an inter-metallic anomaly called purple plaque (a form of corrosion). It was discovered that the Al & Au metals when thermally bonded together did not have a good interaction

210TC · Post by **210TC** » Sun Jun 01, 2008 4:05 pm

I'm having a problem with the cylinders (second set of photo's).
It looks like a rasied surface. Which would indicate the corrosion is fresh. As in since the engine was removed. This corrosion is not where I expected it to be.
This is very hard to determine from photo's.

zuelke · Post by **zuelke** » Sun Jun 01, 2008 7:39 pm

Those photos were taken by the PennYan Cylinder shop within 10 days of the prop strike. There is no way the corrosion happened after the engine was removed from the aircraft.

I fly a lot and I need my airplane back. This business of driving a car back and forth between Portland and Montana is for the birds! I have told PennYan to put my engine back together with a complete cylinder/valve job, flow-matching, etc. They will include all new bearings, etc. and although I will not have a 0 time engine, the engine should be very close to "good as new." I don't plan on selling any time soon anyway.

Thank-you for the support and the suggestions that many of you made. I am going to pursue this issue with Lycoming because owning an airplane is a serious financial stretch for me and all my financial plans have been based on this airplane reaching or at least coming reasonably close to TBO. The prop strike that Betty had is covered by insurance and my savings for engine reserves will cover most of the repair bill, but I should not have had a rusty engine!

I'll let you all know what happens.

Paul Z

PS - Do we get to fly somewhere this summer?? I will be working for the USFS as a volunteer from August 1 thru September 6 at Pittsburg on the Snake river just West a bit from Grangeville (S80) ID.

It is not open to the public - at least not officially - but if you can handle an 900' one way strip we would love to see anyone who would like to come visit. I have a jet boat there and my Maule will be back in service by then and we really welcome visitors! We even have fresh water, showers, and a porcelain flushing toilet!!

Bill Duncan at Alaska Bushwheel and Jeremy A. have been to visit many times so you can call them (or me) for info. The fishing is great - as is the hiking and the scenery. Tons of rooms to tie down and to pitch your tent.

Come visit! 122.9

Paul Z

210TC · Post by **210TC** » Mon Jun 02, 2008 8:14 pm

Paul,
I took the photo's to someone with almost 20 years of test cell work and r&d on lycoming engines. He only does engin's 5 days a week.
His first comment was "Is this plane stored at the coast"?
He said it was highly unlikely the engine came with rust from the factory, because lycoming ships all engine's with a preservative oil in them.
I did not show him the cam picture's. He knew based on the cylinder condition that the cam would most likely have rust.
He said that if we tore down all of the lycoming engine's at our air field better than 50% would have rust in them. We are in San Antonio, TX. 50 to 70% humidity.
He said do to the material lycoming uses in the cyinder they rust very easly. Much faster than I had thought.
He also agree's with A64 on oil temps. He said he would like to see a minimum of 190 degress.
And the only coating that will last is nickel coating.
He mentioned tennis balls on the exhaust and some kind of a dryer on the breather to install after shut down. I forgot the name he used for the dryer.
Read up on nikasil from Mahl in Germany. The Americans have copied this procedure. google "nikasil"
I started using these cylinders back in the 70's (not on aircraft) and this coating is awsome. All Porsche cylinders come with this coating.
I think only two companies in the US can apply on aircraft cylinders.
I have never seen one of these coated cylinders rust.
Just some more info to chew on. I also have to admit that almost all of my engine building background was in Southern California and we did not deal with high humidity/cold climate. Frankly, I would have thought you would need to poor water inside an engine to obtain the level of rust you had on one of your cylinders.
It appears I have been lucky on my engine's.

a64pilot · Post by **a64pilot** » Tue Jun 03, 2008 2:24 pm

FWIW, I bought my 83 Maule from a company in Fl. When I overhauled it at 1800 hrs. it was 23 years old and had spent it's life on the coast in Fl., no rust, none at all on anything internal.

Green Hornet · Post by **Green Hornet** » Tue Jun 03, 2008 2:43 pm

FWIW, Ditto's, I bought my 1997 Maule that was based in Rockport, Texas along the Gulf coast. After the engine was split for Cam / Tappet Valve damage in 2007. It had 800 hours and exhibited no rust at all.

IO-540 Rust

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