Antares 18S Maiden Flight

Andor Holtsmark wrote:
At 17:12 04 June 2006, Eric Greenwell wrote:

I think this is a very narrow view of what a sustainer
can do and how
they are really used. Don't many European pilots often
take a winch
launch, then use the sustainer to get to lift 20 or
30 miles away?


-And how often do they suffer from engine trouble?

Why are these two stroke engines so notoriously unreliable?
When I think about all of the two wheeled vehicles out there that
operate reliably at terrestrial sorts of speeds for years, without the
good flow of cooling air like on an aircraft, I wonder why sustainers
are so problematic. I'm familiar with two strokes being harder to
start, but from discussions here and elsewhere I get the impression they
can be expected to poop out after an hour of use, or less, in the air.
Doesn't seem right. Thoughts? Experience?

Shawn

Why are these two stroke engines so notoriously unreliable?

In many cases, I'm sure, it's because they don't run often enough. Two
stroke or four, it's not that they fail, it's that they fail to start.

Tony V.

Tony Verhulst wrote:

Why are these two stroke engines so notoriously unreliable?

In many cases, I'm sure, it's because they don't run often enough.

I think this is especially likely to be true for sustainer engines,
which are only used for a (rare?) self-retrieve, unlike the
self-launchers which are usually run each flight for the launch. That's
why I think many pilots would be interested in the greater reliability
an electric sustainer could provide, even with a reduced range compared
to a gas engine.

--
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

www.motorglider.org - Download "A Guide to Self-launching Sailplane
Operation"

On Mon, 05 Jun 2006 09:12:12 -0600, Shawn
sdotherecurry@bresnannextdotnet wrote:


Why are these two stroke engines so notoriously unreliable?
Thoughts? Experience?

My personal perception of 2strokes as installed on a DG400 and a
DG600M, is of very good to excellent reliability. Never a problem with
the single cylinder 600, a few problems with the 400 (carb needle
valves, HT wires).

aldo cernezzi

2cernauta2 wrote:
On Mon, 05 Jun 2006 09:12:12 -0600, Shawn
sdotherecurry@bresnannextdotnet wrote:

Why are these two stroke engines so notoriously unreliable?
Thoughts? Experience?

My personal perception of 2strokes as installed on a DG400 and a
DG600M, is of very good to excellent reliability. Never a problem with
the single cylinder 600, a few problems with the 400 (carb needle
valves, HT wires).

aldo cernezzi

I have no first hand experience, but I was under the impression that the
simplicity of the sustainer engines (no starter, etc) means that they
are quite reliable, if only because there is not much that can break.

"Greg Arnold" wrote in message
news:m76hg.11350$KB.6912@fed1read08...
2cernauta2 wrote:
On Mon, 05 Jun 2006 09:12:12 -0600, Shawn
sdotherecurry@bresnannextdotnet wrote:

Why are these two stroke engines so notoriously unreliable?
Thoughts? Experience?

My personal perception of 2strokes as installed on a DG400 and a
DG600M, is of very good to excellent reliability. Never a problem with
the single cylinder 600, a few problems with the 400 (carb needle
valves, HT wires).

aldo cernezzi

I have no first hand experience, but I was under the impression that the
simplicity of the sustainer engines (no starter, etc) means that they are
quite reliable, if only because there is not much that can break.

Small 2-stroke engines which require oil mixed with the fuel will often have
startng problems after long periods of inactivity. The fuel/oil mix forms
gum in the small passages inside the carburator blocking them. I understand
there are spicific 2-stroke oils that reduce but do not eliminate this
problem. The cure is to dismantle the fuel system and clean it with
solvent.

I wouldn't expect a weed eater, snow blower, or lawn mower that has sat with
fuel in it for 6 months or so to start easily. Sustainer engines are no
different.

Bill Daniels

On Mon, 05 Jun 2006 09:12:12 -0600, Shawn
sdotherecurry@bresnannextdotnet wrote:

Andor Holtsmark wrote:

Why are these two stroke engines so notoriously unreliable?

I have been flying with sustainer engines (Solo 2350) for more than 10
years in a Discus bT, Ventus2cT and DuoDiscusT and never had a problem
with it.
Most of the times engine problems are the cause of bad maintenance or
incorrect use of the engine.

AT Parowan last June, one supper conversation with three owners of
powered single seaters detailed two propeller problems (manufacturer
took a season to sort out) and one battery failure (expensive) --
unusual, I suppose. But not engine problems, eh?

Ruud wrote:
On Mon, 05 Jun 2006 09:12:12 -0600, Shawn
sdotherecurry@bresnannextdotnet wrote:


Andor Holtsmark wrote:


Why are these two stroke engines so notoriously unreliable?


I have been flying with sustainer engines (Solo 2350) for more than 10
years in a Discus bT, Ventus2cT and DuoDiscusT and never had a problem
with it.
Most of the times engine problems are the cause of bad maintenance or
incorrect use of the engine.

Charles Yeates wrote:
AT Parowan last June, one supper conversation with three owners of
powered single seaters detailed two propeller problems (manufacturer
took a season to sort out) and one battery failure (expensive) --
unusual, I suppose. But not engine problems, eh?

Were these all two stroke engines? And I'm very curious how a battery
failure could be expensive, given the low cost of batteries.

--
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

www.motorglider.org - Download "A Guide to Self-launching Sailplane
Operation"

Andor Holtsmark wrote:
-To me the disappointing thing is that so much of the
discussion seems to be focused on the motorization
of the self-sustainer version of the Antares 18. There
is a lot more to that aircraft than a way to get home
once you run out of thermals. This aspect seems to
be completely ignored, which is rather strange, since
the goal of gliding is to get somewhere WITHOUT using
the engine.

Well, it's a very pretty (and certainly not affordable by me) 18M
glider, but how much is there to discuss given the lack of a measured
polar, and any real performance comparisons with 18M gliders from more
established manufacturers? What makes the 20E interesting to most of us
is its electric motor. The only thing that makes the 18T interesting,
at the moment, is the lack of an electric motor. If it runs away from
the ASG-29s, LS-10, LAK-17As, and V2Cs at the WGC, I'm sure we'll all be
more interested...