Turbo engine maintenance

On Thu, 6 Oct 2005 07:02:54 -0700, "Matt Barrow"
wrote:

snip

You'll have to forgive my language, but somehow if I tell an owner
something out on the shop floor, or in the 'groups based on my
personal experiences (and experiences of other "unknown" professionals
in the industry) it's hearsay and/or an OWT, but if it gets published
on Avweb, it's freakin' stone tablets handed down from the heavens.

And many people accept OWT with NO substantiation. Take it on "faith", ya
know. How much proof do youoffer when you tell someone something on the shop
floor? How many people have never heard one word of substantiation for doing
theings the way they did other than from the logical fallacy of Argument
From Authority?

How does Avweb differ from "the logical fallacy of Argument From
Authority"?

snip
I am not disputing the advantages to PROPER LOP cruise operation-on
engines proven to operate LOP-for example, the TCM-powered Malibu was
specifically designed to operate LOP. BUT-if you do not know EXACTLY
what you are doing running a turbo-supercharged GA engine LOP you can
DESTROY your engine. If you don't want to take my word for it, re-read
the article at the link you provided.

You can destroy your engine running ROP, too. You can ruin it using numerous
techniques IF YOU DON'T KNOW WHAT YOU'RE DOING.

I'm going to try and keep this simple. The original poster is thinking
about buying one of the most problematic (in my personal experience)
GA turbo-charged aircraft/engine combos. It is rather obvious that his
personal knowledge WRT operation of any turbo-supercharged aircraft is
lacking. Running this engine ROP, even waaay ROP is less likely to put
him the position to do very bad things.

It takes some specific know-how to do "the big pull" on any engine,
and I will definitely agree that 50-75 degrees ROP is the worst
possible place to be. BTW, following the turbo Lance/'Toga POH %power
chart MAP/RPM/ITT/FF settings is practically guaranteed to reduce
engine/cylinder longevity. The only one I personally aware of that is
worse is the original PA46-350P POH numbers.

snip

Yes...so?

As I recall, I initally suggested that someone considering operating a
TIO540 LOP should get more information WRT detonation from the one
person in the industry that is likely to have that information. As it
happens, the article you referred to mentions this same issue, but not
this particular engine.

Matt B.

(Five years and 1400 hours LOP in a TNIO-550 without a burp).

Nice, when did TCM start making one of those? What's the TC #? It's
pertinent to turbo-supercharged Lycoming operation how?

BTW, I am familiar with the IO-550. I would hope that whatever
organization has the STC to modify an 550 to "TN" status would use
GAMI's research data and at least provide basic
documentation/information for LOP operations, if they are recommended.

Assuming that LOP ops are recommended, I can also assume that there
is a given cruise rpm/FF range used to calculate the proper LOP power
settings at WOT-since this just about the only way I am aware of to
calculate a reasonably accurate LOP % power.

I would further reason, based on IO-550 experience that the TO FF's
need to be increased slightly after adding the "TN" to the IO-
engine. The wonderful self-leaning fuel pump used on the
normally-aspirated 550 was notorious for running too lean ROP/too hot
in TO/climb.

I would also guess that there likely is a warning to avoid all
operation between approx. 50 degrees LOP and 100 degrees ROP at high
power settings. This again, would likely be to avoid detonation.

Where do you suggest that the OP would find TIO-540-S1AD LOP
operational guidelines (based on actual testing, I would hope)
similiar to these?

Perhaps by contacting "the LOP/GAMI guy" ?

TC

(17+ years allegedly maintaining TIO-540-J2B, J2BD, F2BD, S1AD, AE2A &
V2AD's for 100,000+ hours of operation with minimal "burps" if
operated IAW Lyc SI1094D C. 7. & 9.)