Engine odyssey

Did you go for Superior Cylinders?

If it was me, I would go for Superior everything as if that experience doesn’t make it clear…

But… the US engine shop I use uses Lycoming cylinders because they regard them as better than Superior… well until this

One anecdotal “failure” and everyone’s getting their panties in a wad and condemning mid-time or higher engines ?

For every pre-mature “failure”, I can show you 10 non-failures …

That said, that engine was over 20 years in service, most likely the cause, not the 1000 hours TIS.

I don’t think that’s the case with this thread Michael, as Peter says, almost every engine that fails has probably sat around at some point.

That’s why it was a shame in the “Flying Reporter” thread where they had a 2,200 hour engine that was, on the face of it, being regularly flown, that more detailed information was not shared. Instead of people getting all sensitive about “questioning their engineers”, it would have been nice to know if it ever sat unused for more than say 4-8 weeks. The most interesting failures are from regularly used aircraft and this was a perfect example where accurate reporting would have been useful.

I know the whole history of my engine and it has flown on average weekly (2 weeks maximum idle) so with 25 hour oil changes and Camguard I will definitely share my tear down if it fails prematurely.

What examples of long time engines do you have Michael? I’m hoping to run my bottom end to at least 3,000 hours and we’ll see what happens to my Superior Cylinders!

The most interesting failures are from regularly used aircraft

Yes exactly, and the “suspected corrosion” cam+follower disintegrations are really rare on engines which have a proven regular flying record. In fact I have never heard of one.

Also

For every pre-mature “failure”, I can show you 10 non-failures …

would suggest a 10% engine failure rate which would rapidly ensure we are all broke, or dead

Some concrete examples would be useful info.

My O-320 suffered a corroded front most cam profile after 2350 hours of regular, weekly use and never idle for longer than an annual inspection.

The engine was actually investigated for bottom plug fouling, which was later rationalised as oil being drawn into the cylinder by late valve events caused by the degraded cam. Like the stumbling reported above, I’m not convinced that this problem was linked to the reason that the engine was condemned.

It seems to me that we hardly ever get to the real reasons for funny engine behaviours, but there’s eventually some unrelated defect that triggers off a rebuild. As a result, our pool of wisdom about this 70 year old technology hardly ever advances.

That’s an interesting data point, Aveling. Did you fly that plane for the whole 2350hrs?

No, it was initially a club plane for about the first 1500 Hrs. I flew most of the rest. It was about 7 yrs total to the end of the engine.

Toward the end (2100+), two of the cylinders were replaced with 2nd hand articles because of suspected cracks around the plug holes. I still have those cylinders and a friend, a very experienced engine mechanic, has examined them and can’t find any cracks. Cam corrosion was not reported then, but 150 hrs later the oiling up came on as mentioned above. So apparently the cam corrosion occurred in the last 150 Hrs of life, when the plane was still flying every week.

Call me a cynic, but I can’t help wondering how long the engine would have lasted if it hadn’t been meddled with. It was a wonderful starter, used negligible oil, and never missed a beat.

On Lycos, typical cylinder cracks occur around the lower spark plug hole, between the hole and the exhaust port next to it. They are easy to check for at the 50hr check (shine a torch up the plug hole) but most owners don’t do that check until the Annual. If you can’t see any cracks even when looking at removed cylinders, there probably aren’t any.