Engineering types - MTBF Lycoming IO-540

[Daifly]

Anyone any idea on the MTBF of the Lycoming IO-540?

And a link to somewhere internetty where I can see it?

Many thanks,

Daifly.

[IO540]

That's a really interesting question - at least to those who have ever calculated the MTBF of some complex product.

Did you know that the MTBF of a human comes out to something like 500 years? That says it all.

I bet the MTBF of an IO-540 would come out to something far more than 2000 hours of operation - very possibly 100k hours. But it is probably true that not one engine would make more than about 10k hours, even under the most optimal conditions.

[Daifly]

Thanks for that, I think!?

I need a little more definate information than a guesstimate though, have been trying to speak to the CAA's SDEU all day to no avail.

MTBF for the PT6 Turboprop is some 346,000 hours.... slightly more than the 10,000 for the Lycoming!

Any more pointers gratefully received.

Daifly.

[A and C]

This is a bit of a hard question to answer as the IO-540 comes in a number of variants. At the low power end there is the low compression 270 HP engine and at the top end is the TSIO-540 that makes 300HP and drives the cabin pressurisation , these are two very different engines.

If you remove the two big AD's that have happend of late ( crankshaft failure and red gear bolt ) due to poor quality control the engine is very reliable with few in flight failures but the main reason for most of them not making TBO is lack of use !.

This engine more than most seems to suffer from camshaft failures , I think that this is due to a combination of factors and happens most often on low utalisation aircraft.

In MY OPINION this is due to the oil slowly draining from the camshaft over the weeks of not being used and the distance between the front cams and the oil pump resulting in the lack of oil on the face of the front cams on start up.

It is MY OPINION that using one of the semi-synthetic multi grade oils will help as the thinner oil on start up will flow to the front cams faster and these oils tend to "cling" to the cams for longer during periods of inactivity.

[Daifly]

Thanks A and C - that's useful information.

I'm specifically looking at the Lycoming IO-540-K1B5 and the
Lycoming O-540-E4C5 as fitted to the Islander.

I should add that there is nothing sinister in all of this, it's a comparison I'm doing for a project that I'm undertaking comparing pistons and turbines and I have all other engine data but not these particular engines.