My Ney Enterprises Re-Man Lasted 200 hours

N. Shane wrote in message . ..
Caution to those pondering a zero-choke re-man by this company.

My O-470J lasted 200 hours before four cylinders showed mid-fifties
compression with Blackstone labs reporting symptoms of excessive ring
wear.

Even after admitting, view phone, that the test-stand results were
abnormal, Ney himself refused to stand behind the engine, on the
grounds that the plane's former owner -- his customer -- made him use
reconditioned cylinders.


That's one of the problems with buying a plane with a recent overhaul.
There isn't much of a chance that the seller did a good job of
overhauling the engine if he's just hours away from selling it. You'd
probably be better off buying a run-out airplane and getting the
overhaul done yourself. Also, you'd know that the engine was properly
broken in.

-Robert

Robert M. Gary wrote:




That's one of the problems with buying a plane with a recent overhaul.
There isn't much of a chance that the seller did a good job of
overhauling the engine if he's just hours away from selling it. You'd
probably be better off buying a run-out airplane and getting the
overhaul done yourself. Also, you'd know that the engine was properly
broken in.

For purposes of avoiding one when buying, what's a "recent overhaul"?
100 hours? 200? 300? Put another way, after how many hours on an engine
can you tell that it's properly overhauld and broken in?

xyzzy wrote:

Put another way, after how many hours on an engine
can you tell that it's properly overhauld and broken in?

It's not really hours so much as calendar time, IMO. If the engine was overhauled
within about the last six months and there are no extenuating circumstances (such as
lost medical or death of the owner) prior to that, I would be a little leery of the
quality of the work. On the other hand, a "name" shop like Mattituck doesn't cut
corners on request for anyone (though their engines *have* failed on occasion), so I
would tend to assume the work was good if it came from one of those shops. There are
other factors besides time.

AFAIK, there's no way to really be sure that the engine was properly broken in,
especially with chrome cylinders.

George Patterson
If you want to know God's opinion of money, just look at the people
he gives it to.

Gene Kearns wrote in
:

Now their latest approach (almost certainly to stave off
a class action suit) is just to continually lower the limits on an
"airworthy" cylinder. It's now so low (26/80 with air leaking past
the rings and valves, and a pressurized crankcase) that pretty much
any piece of scrap iron is considered "good" by TCM.

I'm not going to champion the quality of TCM cylinders.... but
28/80???? Where did that come from? AFAIK, they still require the
calibrated orifice test (per SB03-3) to establish the minimum
allowable pressure.... and I have *never* recorded a pressure *that*
low...

It's 26/80, not 28/80, so slightly worse than you thought. G

Where does it come from? It comes straight from TCM. Used to be the
requirement for airworthiness (according to TCM) was 40/80 with audible
air leak only past the rings (anything past the valves was automatically
failing). About 10 months ago, to head off numerous lawsuits, TCM
issued an updated "standards" circular with the MUCH lower requirements
for a "good" engine.

As for the reading itself, the true reading on most of these engines is
closer to 0/80. Once the problem starts to manifest they quickly wear a
"step" near the upper part of the cylinder. Pressure is supposed to be
tested at TDC. What you will find is that the reading is essentially
0/80 (I've seen 3/80 and 7/80) when the cylinder appears to be TDC by
normal means (a dowel rod on the top of the cylinder). *BUT* you can
wiggle the prop the most microscopic amount and sometimes hit a spot
where it will suddenly jump to something more like 78/80. You've caught
the rings right under the step. [All this assumes, of course, that
there isn't too much air leaking around the valves.]

The comment from the southern USA rep for TCM - "Hell, if it will pass
the annual, why do you care?"

jmk

On Thu, 09 Sep 2004 10:47:11 -0400, Gene Kearns
wrote:


I think you have been grossly misinformed.

I just spoke with the person at Teledyne Continental that writes the
service publications and he was utterly unaware of your ""standards"
circular" and emphasized the fact that SB03-3 is *still* the standard
for checking cylinder leakage.

Maybe just a little misinformed. The "low" reading (as you have
indicated) is still determined by the orifice tool. I've never
personally had a comp tester come in using this method under around
35.

They have changed the verbosity to allow initial e&i valve leakage
(originally, any valve leakage was verboten), but if the valve/s are
still leaking on the "re-check", the cylinder gets yanked.

TC

Gene Kearns wrote in
:


I think "grossly" fits.... bear in mind that the poster offered a
statement, "About 10 months ago, to head off numerous lawsuits, TCM
issued an updated "standards" circular with the MUCH lower
requirements for a "good" engine. " And then backed the statement up
with anecdotal evidence, "The comment from the southern USA rep for
TCM - "Hell, if it will pass the annual, why do you care?" "

I'd still like to know *which* document sets forth this "standard."

And personally, I've never had a calibrated orifice test go as low as
35... usually it is around 43. Lower than Lycoming's suggestion,
perhaps, but then they don't *require* a borescope at inspection...
and their standard is: if the test is below 60/80 cylinder repair
should be "considered."

Been grossly misinformed about many things in life, including women. But I
don't think so this time. First off, TCM has always allowed readings as
low as 40/80 to be considered good - this change into the 20's just lowers
it further. The exhaust valve leakage is new - used to be any valve
leakage was failing.

If you are getting 35/80, then you have a GREAT cylinder from TCM.

I'll look for that TCM AC. Should have a copy back at the other office.

jmk

"James M. Knox" wrote in
2:


If you are getting 35/80, then you have a GREAT cylinder from TCM.

I'll look for that TCM AC. Should have a copy back at the other
office.

FWIW... tried the TCM site (which, as always, left me more frustrated than
anything else). The primary item was SB03-3, which was revised last year
to greatly reduce the requirements for a "airworthy" cylinder. I was wrong
about one thing - I still thought that leakage past the intake valve wasn't
permitted, but in fact audible leakage past all valves and rings is now
considered normal.

Unfortunately, the reference to the actual leakage limit is in another
document, and (as usual) their links are broken. So I need to find a hard
copy somewhere.
jmk