Turbo engine maintenance

On Mon, 10 Oct 2005 20:43:21 -0400, "John Doe"
wrote:

TC,

Thanks for taking the time to comment on my posts. The plane just went into
the shop today for a prebuy and I'll have some words within a day or two on
the status of the engine.

It appears you're not a big fan of the Turbo Lance. What do you recommend
as a better combo? I've look at an A36 but they're quite a bit more cash
for not alot of gain. I think my other option is to give up on the turbo
and just look for a straight tail lance that's in good shape.

Have allegedly been around the block with the Turbo Lance, the Turbo
Saratoga (fixed-gear and retract-SP) but not the 'toga II TC. Have
been under the hood of a couple of 'toga II's, took one for a ride and
liked what I saw, but they were coming out as I was getting out of the
business-have no real experience with them.

When I got out a few years ago, the Turbo T-Lance was cheaper than
anything else in it's class. Personally, I was never too fond of the
way that they behaved in the air (compared to the T-tail or straight
tail NA Lance, or the Cherokee 6), and don't care for the engine
installation at all.

Unfortunately, and please don't take this personally, it means that
they tended to attract a certain type of owners, and often were not
well-maintained or operated properly. As Mr. R has indicated, it also
meant, however, a few years ago, you could buy a lot of airplane for
less.

The engine/install has recurring AD issues on the exhaust, a funky
up-draft cooling system, and runs HOT. The Turbo 'toga SP installation
is almost identical, and also runs hot, but not quite as hot for some
reason (cruise speed?).

If you look at the Deakin dude's thoughts on max CHT/oil temp with
regard to engine longevity, a stock T T-Lance operated at 75% power at
cruise is going to exceed these numbers during operation at even
slightly elevated OAT's. Basically, a lot of the time it is going to
be a 65% power cruise aircraft.

Even operating at 65% it can be pushing acceptable CHT/oil temp
limits. Put Turbo 'toga upper cowl "gills" on a couple, didn't seem to
help much-but it did help keep the paint on the top cowl from
blistering after shut-down. As I indicated to you in earlier posts,
for whatever reason, the intercooler kit removes most of these
limitations. I'm sorry I don't have more info, but the last I had
heard, the intercooler company's assets had been sold, which is a darn
shame.

Had one intercooled Turbo 'Toga SP that I took care of (before, during
and after the intercooler install), and really, really enjoyed flying
it. I assume the flight characteristics changed from both the tapered
wing and the straight tail. A 300 hp Cherokee Six, or Lance can also
be a nice choice. If you are a flat-lander and not hell-bent for
speed, their performance is better than what you would expect. It is a
lot harder to abuse the normally-aspirated engine, and the
installation condition (baffling, etc) is not as super-critical.

The A36, unfortunately is in a different class. The cruise performance
is excellent, and there really is no comparison between the
construction of the aircraft and it's mechanical systems. Again, as
Mr. R indicated, you don't get something for nothing. They are more
expensive to purchase, but realistically are not really that much more
expensive to maintain (if you compare to the Lance or the retract-SP).

I allegedly had the opportunity to take care of a couple of the
factory IO-550 versions, and converted one to the IO-550
configuration. Never had the opportunity to fly it, but had one show
up on the ramp with an STC-installed 350 HP TIO-540. If that
installation works as well as the Chieftain does, it would be just
about the ultimate A-36. In theory would make real close to the same
power @ 65% as the IO-550 @ 78% (max continuous HP).

Unless things have changed a whole lot in the few years, a clean A36
is as close to a sure thing to buy, fly, and if you don't bend it,
sell at a profit as you get in GA.

Hope some of this helps;

TC