Engine management

[DRL]

It's NOT an OWT according to both ECI and Lycoming techs.
You can find any answer you want on the Internet.
Bill

Absolutely, true, everyone with a keyboard can be an expert. Although, the author of that article was very knowledgeable regarding R2800's, but he is only one opinion.

I would bet, if you called the techs back, you might yet get different opinions and a call to the engineering department another idea. It is not surprising the manufactures would place blame else ware. This is an old and unresolved question, that has been much discussed. Engine size, turbo chargers, shock cooling etc. are certainly factors. The operating manuals do not have restrictions against operating at idle, so a cynic would say, they just want to sell more engines, or maybe they don't really believe it is an issue.

There are so many variables, it could be related to mishandling parts, material defects, assembly error, run-in mistake, built on Friday, you may never know for sure why this happened. I doubt it was anything that you did that would result in that severe damage, just an opinion.

[seastar]

There are so many variables, it could be related to mishandling parts, material defects, assembly error, run-in mistake, built on Friday, you may never know for sure why this happened. I doubt it was anything that you did that would result in that severe damage, just an opinion.

All true. I don't think I did anything wrong either, except maybe pulling back to idle in flight.
The only thing I know for sure is what it has cost me to repair and perhaps the loss in value.
Wont know that until I sell it.
Bill

[John Hodges]

How did your shop determine that this was a ring flutter problem? Ring flutter is a design problem, or a result of running the engine outside it's operating limitations. If we have a design problem, we would see more of these kinds of failures. We have not, so far as I know, seen more than isolated incidents of low time engine failures.

Now that you're back in the air, fly the crap out of it, do it often, and keep us all posted on how it's going.

[seastar]

John
According to the techs I have talked to at the factory you are correct, ring flutter is a "design problem".
The piston groves and rings must be designed with clearances to allow for heat expansion that does not occur in a water cooled engine.
An aircraft engine must operate loaded to the max with cylinder temperatures from about 0dF to 475 dF.
Cooling air from -50dF to +120 dF.
A water cooled engine operates with cylinders at about 180df to 200 dF.
Thats a very big difference in expansion of the metal parts.
The aircraft piston and rings must be designed to accommodate this temperature spread and therefore has looser fitting rings, or so I was told. Additionally at the high end the rings become less elastic.
That induces "ring Flutter" under some conditions.
But what do I know ----- except mine failed.
I had never heard of "ring flutter" (or paid attention) until this happened.

I do know this ---- an engine failure in flight is no fun.
In my 5500 hours I have lost an engine twice.
Once in a Mooney that was not the fault of the engine but a carb heat flapper valve and another in a Navajo IFR at 11K feet over the Smoky Mountains. That engine swallowed a valve.
I'm getting too old to experience another in flight failure.

I checked with my shop and while we don't have the cylinders (ECI insisted we send them back to them) we do have the pistons, rings and defective valve train parts.
I am on my way to Fort Lauderdale to attend the boat show and will return to Indianapolis just before Thanksgiving.
I will try to get some pictures and post them when I return.
Bill

[jlezin]

Thanks Randy. I appreciate the response.
My problem is I have 4 new cylinders to break in and am now not sure how it should be done.
Should I take the advice I received from Titan or is there some procedure that CubCrafters recommends that I am not aware of?
Essentially Titan recommends running the engine at 65-75% power for 50 hours.
Of course no one (including CubCrafters) provides power curves for that kind of power because of the Light Sport limits. That leaves me and others guessing.
Titan also said that any cylinder head temperature up to 450 was OK for sustained operation.
Seems a bit high but they insisted it was OK.

Titan also says that most damage occurs if the power is pulled all the way back in flight when landing causing the prop to drive the engine.
Supposedly that causes ring flutter and damages the piston, the rings and the cylinder walls.
Thats what I suspect caused the damage to my engine.
I learned to fly in a J3 and was trained to pull the power back all the way opposite the numbers and that's what I have always done. Titan says that will damage any engine.
Maybe someone else at the factory can chime in since you are in Europe?
Bill

What I found out about this engine is rather counter-intuitive and represents my own findings, not those of the factory or ECI. When I broke my engine in, I had a lot of trouble keeping the CHT's below 400 degrees. Admittedly it was warm in Yakima with lots of smoke. I did a number of conventional things trying to lower the CHT's: keeping it full rich, dropping the nose, lowering the manifold pressure, running on just one side of the ignition, keeping the plane light as possible. Nothing I tried seemed to be very effective. Then I tried LEANING the mixture and that had a dramatic effect. During my 36 years of flying, I was taught to richen the mixture (use gas to cool the cylinders). But with this engine, it seems to react the opposite way. There is some logic to this, because you're making a smaller fire . . .
So if you are breaking in your engine and can't seem to get the temps down, try throttling back to 2100 rpm and lean aggressively. It worked for me, although I was quite far down the break-in road when I discovered it.