New Bombardier-Rotax engines

"Thomas Borchert" wrote in message
...

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

Not in cruise.

Even in cruise, the engine will run much higher rpms than your "usual"
engines. Your current engine will run 1200 rpm to spin the output shaft at
1200rpm, the new engine will be running 3600rpm to spin the shaft at
1200rpm. If you don't believe *Me*, ask someone competent to do the math
for you.


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


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

Liquid cooling does become an issue when you run out of coolant. A 2 gallon
reservoir is fine on a test stand with 3 techs standing around to keep an
eye on the run, but at night in the clouds or mountains, you will be
wondering how long it will take the engine to overheat and time to an
airport when a hose or gasket lets go.

Will an "engine in general" run for more than 30 minutes without coolant,
and would you bet your favorite coon dog's life on it?

Pepperoni,

the new engine will be running 3600rpm to spin the shaft at
1200rpm. If you don't believe *Me*, ask someone competent to do the math
for you.


Well, yes, but will that affect engine longevity in any way? That's the
question.

As for liquid cooling: Your oil/air cooled engine won't work either when the
oil leaves. Happens a lot, doesn't it? Oh wait, it doesn't. Hmm...

--
Thomas Borchert (EDDH)

Thomas Borchert wrote in message ...
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?

I didn't say it was impossible. Maybe I should rephrase that to say
"...looks like it'll make it difficult to cost-effectively retrofit to
existing designs".

From what I've seen over the years, most firewall forward engine
conversions tend to approach the value of the unconverted plane.
Unless these engines are going to sell for substantially less than
their air cooled bretheren, all of those necessary bits and pieces are
going to make the conversion look pretty unattractive from an economic
standpoint (at least for the lower end of the market, i.e C-172s and
PA28s).

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

John,

Depends on a lot of factors. Let's look at the Thielert Centurion 1.7
diesel, not yet available in the US (due to stalling of the FAA,
AFAIK), but certified in Europe. AFAIK, the engine is 20,000 $,
including all accessories and a guarantee for 2400 hours (TBR) or 12
years. If something breaks before, you'll get the new engine prorated.

The conversion kit for the 172 is 40,000 $. The Centurion will use 4
gallons or so of JetA1.

If you calculate the difference between the amount of JetA1 used by the
Centurion and the Avgas used by an O-320, factor in the cost of the
engine per hour (guaranteed with the Centurion, full of surprises with
the Lyc), you'll find that the point at which you'll get the extra
20,000 for the conversion back depends very much on local fuel cost and
similar factors - but the point will come.

--
Thomas Borchert (EDDH)

Had a problem with the V8 engine on my BMW 740i. The BMW V8s
originally came with aluminium cylinder liners. It was found these were
affected by (if I remember correctly) the sulphur in petrol. These
eventually caused a failure in my engine (well, when my father owned the
car). The liners were replaced with steel ones. Apparently BMW were
supposed to fit these for free, but since we didn't have a full BMW service
history, my father had to pay...not cheap!

http://www.koalamotorsport.com/tech/...shortblock.htm

By the way, is this the process you're talking about?

http://www.autofieldguide.com/columns/jeff/0600mat.html

Looks like if you want to see if it works over time, watch some
Mercedes cars...

Paul

"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?