Do brand new big bore Continentals require top end overhaul at 400 hours?

I've been talking with a guy who is a new owner of a Bonanza. It has
a Continental IO-520 for an engine. It now has over 1800 hours and
he's been looking at overhaul companies. I asked him what he was
planning and he told me that the cheapest way to get an engine is to
buy a brand new one from Continental, but he's reluctant to do that.
He's reluctant because he said they typically require a top end
overhaul at around 400 hours, that they never make TBO. In fact his
airplane's engine was diagnosed with a leaking exhaust valve just a
few days ago and has the cylinder off right now.

John Deakin has also stated his opinion that Continental just cannot
seem to manufacture an engine that lasts beyond 400 hours without
requiring top end work.

My acquaintence is leaning towards sending the engine to a builder
that uses a non stock new cylinder for it's engines, and installs GAMI
injectors as a standard. They dyno the engine to verify performance
before shipping. This "overhaul" ends up costing more than a new
Continental.

So the question is: Is Continental really incapable of producing an
engine that will actually last to TBO?

Thanks, Corky Scott

"Corky Scott" wrote:
So the question is: Is Continental really incapable of
producing an engine that will actually last to TBO?

You will hear lots of anecdotal evidence both ways. Aviation Consumer
recently ran an article on cylinders that included an owner survey.
Continental cylinders came off a poor third in quality to Superior and ECI.

My anecdotal contribution is that Continental owners I know do not use
Continental cylinders for overhauls.
--
Dan
C-172RG at BFM

"Corky Scott" wrote in message
He's reluctant because he said they typically require a top end
overhaul at around 400 hours, that they never make TBO.

I've heard the same thing about the big Lycomings too. My anecdotal evidence
includes 19 TSIO-520 Continentals that went to TBO. The only problem was a
bad batch of aftermarket chrome cylinder plating on 4 cylinders of one of
the overhauls.

The secret is knowing how to run these engines.

D.

Capt.Doug wrote:

"Corky Scott" wrote in message
He's reluctant because he said they typically require a top end
overhaul at around 400 hours, that they never make TBO.


I've heard the same thing about the big Lycomings too. My anecdotal evidence
includes 19 TSIO-520 Continentals that went to TBO. The only problem was a
bad batch of aftermarket chrome cylinder plating on 4 cylinders of one of
the overhauls.

The secret is knowing how to run these engines.

The real secret is to not get Continental cylinders. Pure crap.

On Mon, 23 Aug 2004 23:19:33 -0600, Newps wrote:

The secret is knowing how to run these engines.

That may be, but John Deakin has opined that no matter how you run
them, they will require top end overhaul at around 400 hours. He's
not sure exactly why, but thinks that the problems arose when all of
Continentals old timers retired and no new engineers were hired.

The real secret is to not get Continental cylinders. Pure crap.

If this is in fact the case, why wouldn't the FAA be interested? Or
perhaps they are?

Corky Scott

If this is in fact the case, why wouldn't the FAA be interested? Or
perhaps they are?

Corky Scott


No catastrophic failures, (cracks, loss of heads) just premature wear .

Allen

Corky Scott wrote in
:

That may be, but John Deakin has opined that no matter how you run
them, they will require top end overhaul at around 400 hours. He's
not sure exactly why, but thinks that the problems arose when all of
Continentals old timers retired and no new engineers were hired.

It's not that you will never get a TCM engine past 400, but rather that
most of them won't go much past. There is a standard "pattern" that
they have problem with, and it is extremely obvious signs.

Basically the problem is that TCM always got flack for their engines
using more oil than Lyc. engines of the same size. So about a decade
ago TCM redesigned their cylinders - and sort of succeeded. Trouble is,
they succeeded too well.

A large number of these engines will break in with ZERO oil usage. They
will stabilize such that, 50 hours after oil change, you won't find a
bit of oil loss. Originally owners were happy. Trouble is, that oil is
needed for lubrication.

So what happens is that right around 400 hours the engine starts using
oil. Not so much burning it, as typically blowing it out the crankcase.
Another hundred hours or so and it is really bad, oil all over the
belly, and compression is down around 0 *unless* you "play" with the
engine while doing the test.

Several minor design changes have not solved the problem. TCM's
response so far has been to continually reduce the requirement for a
"working" engine - currently 26 over 80 is acceptable, with a
pressurized crankcase and leakage past both the rings and exhaust valve.




The real secret is to not get Continental cylinders. Pure crap.

I would recommend overhauled rather than new TCM's.

jmk

"Corky Scott" wrote in message
...
On Mon, 23 Aug 2004 23:19:33 -0600, Newps wrote:

The secret is knowing how to run these engines.

That may be, but John Deakin has opined that no matter how you run
them, they will require top end overhaul at around 400 hours. He's
not sure exactly why, but thinks that the problems arose when all of
Continentals old timers retired and no new engineers were hired.

So you recall which article stated this? I recall Deakin talking about all
the Trade-a-Plane copies that had STOH numbers at 800-1200 hrs. The context
about that was running ROP.

The F33 I'm trying to buy (IO-520) has 3500 hours and never had a TOH and
was replaced with a REMAN at 1800 hrs the first go round.

On Tue, 24 Aug 2004 08:25:48 -0700, "Tom S." wrote:

So you recall which article stated this? I recall Deakin talking about all
the Trade-a-Plane copies that had STOH numbers at 800-1200 hrs. The context
about that was running ROP.

The F33 I'm trying to buy (IO-520) has 3500 hours and never had a TOH and
was replaced with a REMAN at 1800 hrs the first go round.

If I recall correctly, it was in one of his mixture series of
articles. That at least narrows it down to five.

Corky Scott

"Corky Scott" wrote in message
...
On Tue, 24 Aug 2004 08:25:48 -0700, "Tom S." wrote:

So you recall which article stated this? I recall Deakin talking about
all
the Trade-a-Plane copies that had STOH numbers at 800-1200 hrs. The
context
about that was running ROP.

The F33 I'm trying to buy (IO-520) has 3500 hours and never had a TOH and
was replaced with a REMAN at 1800 hrs the first go round.

If I recall correctly, it was in one of his mixture series of
articles. That at least narrows it down to five.

He did say in a couple of articles (okay...in a LOT oaf articles) that TCM
and Lycoming have sucked at QC over the past 15-20( ?? ) years, but I can't
remember that 400 hour bit. I do remember the 800-1200 TOH bit, though that
was more to improper mixture, not QC. I do recall something about their not
making something or other, and the neither company was worth a damn about
honoring their warranty, but again, IIRC that was to do with ROP AND their
crappy QC.