New Bombardier-Rotax engines

"Big John" wrote in message
...
rgb

We've had aluminum auto engines without liners and as I recall they
had a pretty high cylinder failure rate?

Chevy Vega. About as close to100 percent failure rate as you can get.

rgb wrote in message ...

Some folks seems to be pretty please with there Rotax 912S so I was
thinking those 2 new engines might give Lycoming and Continental a
little challenge, maybe not ...
For what I can see thoses good old Lycomings are quiet good, but kindof
expensive .

Liquid cooling looks like it'll make it difficult to retrofit to
existing designs. I wouldn't be surprised to see a company like
Diamond modify one of their designs for it.

How they can run a 10.8 to 1 compression ratio on 87 octane gas is a
neat trick. I'm sure temp stabilization from liquid cooling helps,
but that still seems like a very high ratio for the low octane fuel.

John Galban=====N4BQ (PA28-180)

Corky

Tnx for adding more info to the thread. Knew there were others with
some good basic data.

On their hard inside coating of the cylinders, unless it has the same
expansion rate as the aluminum block I would expect sluffing off and
failures? If they have solved this problem may have a winner?

Also running on a test stand will check a lot of things about the
engine but giving it to the 'numb nuts' in the field and letting them
operate is the only way to really check out.

Some of the things I invented and patented, I checked for 100's of
thousands of cycles and yet when put in field, always found someone
who could tear them up G I guess you call that trying to design for
the lowest common denominator (which don't always work as the lower
you get on the "Darwin' scale the harder it is to keep people from
using the wrong way and tearing up). G

Do wish them success using current technology which might cause Lyc
and Con to upgrade???.

Big John





On Fri, 17 Oct 2003 19:42:33 GMT,
(Corky Scott) wrote:

On Fri, 17 Oct 2003 09:49:00 -0500, Big John
wrote:

rgb

We've had aluminum auto engines without liners and as I recall they
had a pretty high cylinder failure rate?

If they have solved that problem with their 'electro-deposit' coating.
fine, but I sure wouldn't be the 'first one' to buy.

Think one of the problems is that any coating of the aluminum cylinder
expands at a different rate than the aluminum and this starts the
failure?

Should be some experts on aluminum engines around here on rah that can
give good technical advice about what they are trying to do and
expected results and longevity.

Big John

Big John, the only all aluminum engine I can recall that was like you
describe was the four cylinder engine in the Cheverolet Vega. That
engine was cast from aluminum that had a high silicon content, and the
cylinder bores were etched such that the aluminum was dissolved away
and the piston rings scraped on a silicon surface. You're right, that
didn't work, or at least didn't work well. Didn't sound real snappy
either, my recollection was that it was a great imitation of someone
going "duuuhhhh". Bombardier isn't using that technology, they are
electro plating the cylinder bores with nickasil. The piston rings
aren't scraping against bare aluminum.

I think I read somewhere that the Bombardier engines have been run for
literally thousands of hours on test stands. So they appear have
already run to TBO and beyond. If they did not run successfully, do
you think they'd be displaying them now?

For those who worry about the numerous piston cycles and how at the
high rpms it would wear excessively, it doesn't happen that way.
Small pistons running at high rpm just do not wear at the same kind of
rate that large pistons whuffing slowly away do, so you can't compare
them directly.

Liquid cooling is a **GOOD THING**, not bad. It means carbon monoxide
free heat for the cabin and no worries about shock cooling. If
automobiles can run their water pumps for 10 years and longer without
failing, I'm guessing Bombardier can do it too.

The higher rpm does a lot of nice things too, for one thing, the
engine will be extremely smooth. In addition, it comes with a real
muffler, and spins the prop slowly. This means you could fly out of
any airport, over the most cantankerous of neighbors and not upset
them.

The V configuration makes for a narrow package, compared to Lycomings.
We've, well I have anyway, been beefing about how old the technology
is of aircraft engines. Here's a truly new design, utilizing many of
the features that should give it a very big step up over the slow
revving Lycomings and Continentals. Think of it as half a baby
Merlin.

Bombardier would not have announced such engines, in my opinion,
without having done enormous amounts of research, both from a
technical and market aspect, and tested them exhaustively.

Bombardier isn't Zoche, after all, they are a for profit company. :-)

Corky Scott

Big John wrote:


Some of the things I invented and patented, I checked for 100's of
thousands of cycles and yet when put in field, always found someone
who could tear them up G I guess you call that trying to design for
the lowest common denominator (which don't always work as the lower
you get on the "Darwin' scale the harder it is to keep people from
using the wrong way and tearing up). G

Well-known principle; whenever you think you have a fool-proof design,
they come out with a better class of fool!
--
Alex
Make the obvious change in the return address to reply by email.

alexy

Never heard it that way before but of course your right G

Big John

On Sat, 18 Oct 2003 02:51:23 GMT, alexy
wrote:

Big John wrote:


Some of the things I invented and patented, I checked for 100's of
thousands of cycles and yet when put in field, always found someone
who could tear them up G I guess you call that trying to design for
the lowest common denominator (which don't always work as the lower
you get on the "Darwin' scale the harder it is to keep people from
using the wrong way and tearing up). G

Well-known principle; whenever you think you have a fool-proof design,
they come out with a better class of fool!

Pepperoni,

The problem that I see is that

Based upon what? Are you an engine construction engineer specializing in
aluminum engines? Or is it just "gut feel"?

the engines run up to 6000 rpm, and are geared 3:1.

Not in cruise.

but more
problems seem folded back in with the liquid cooling.


Again: Says who? Liquid cooling seems to be a total non-issue with the
Rotaxes, the new diesels and engines in general.

--
Thomas Borchert (EDDH)

Rgb,

I don't know alot about engines


So how do you know the material they are made of is a problem, as you
say in your original post?

--
Thomas Borchert (EDDH)

Rgb,

For what I can see thoses good old Lycomings are quiet good,


Well, time to become an owner then. And then you'll change your mind real
quick, after, say 600 hours or so.

--
Thomas Borchert (EDDH)

John,

Liquid cooling looks like it'll make it difficult to retrofit to
existing designs.


Why? The Thielert diesel is liquid cooled and is being retrofitted to
C172s and PA28s as we speak. Everything firewall forward is replaced,
so where's the problem?

--
Thomas Borchert (EDDH)

Jim,

Well, then check on the prices for the Thielert. You'll be surprised.
Also, the sma has come down to 60k, AFAIK.

--
Thomas Borchert (EDDH)