New Bombardier-Rotax engines

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)

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)

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)