alternate engine in Falco

There are many aircraft that allow for a variety of engines. Some
engine makers even supply cowling/nose bowl kits for popular types
(Rans, Vans) etc.

So, what do you think of using a Jabiru 5100 (8 cyl) in a Falco in
place of the Lycoming io-360?

Jabiru is narrower and less tall, but is a few inches longer (but
might fit in an unmodified cowling given the different mount design).
Similar power, lighter weight.

I have heard the guys at Sequoia are a bit sensitive about even basic
unseen mods, but what do you guys think?

Jonny wrote:
There are many aircraft that allow for a variety of engines. Some
engine makers even supply cowling/nose bowl kits for popular types
(Rans, Vans) etc.

So, what do you think of using a Jabiru 5100 (8 cyl) in a Falco in
place of the Lycoming io-360?

Jabiru is narrower and less tall, but is a few inches longer (but
might fit in an unmodified cowling given the different mount design).
Similar power, lighter weight.

I have heard the guys at Sequoia are a bit sensitive about even basic
unseen mods, but what do you guys think?


Can you do the weight and balance calculations?
And performance predictions?

That's what I thought...

On Jun 27, 12:30*pm, cavelamb himself wrote:

Can you do the weight and balance calculations?
And performance predictions?

That's what I thought...

I'd need help with the balance (CoG) since the nose would be about
70lb lighter (based on engine weight alone, not sure about mounts).

Would have thought performance would be similar with Jabiru @170hp and
the Lycoming @ 180hp.

I think the fuel usage would be better with the Jabiru.

I'm considering building a Falco, but as an AUS based builder I
thought a local engine (of a more modern design) might be an option.

The Falco is a great aircraft, but I see no reason why all aspects of
the specification need be stuck in the 1950s. I'm all for glass
cockpits, updated systems and a more modern powerplant. I have no
plans to alter the look or aerodynamics of the aircraft.

I'd need help with the balance (CoG) since the nose would be about
70lb lighter (based on engine weight alone, not sure about mounts).

Would have thought performance would be similar with Jabiru @170hp and
the Lycoming @ 180hp.


70 lbs is quite a bit difference. Don't be surprised if you have
to move that engine forward for the W&B and to build
a new cowling. Sequoia may not publicly back the idea,
but I wouldn't be surprised if they kept in touch just to see
how it's working. Also everyone involved must remember that
this is an experimental category, so have fun experimenting.
Lou

"Lou" wrote

70 lbs is quite a bit difference. Don't be surprised if you have
to move that engine forward for the W&B and to build
a new cowling. Sequoia may not publicly back the idea,
but I wouldn't be surprised if they kept in touch just to see
how it's working. Also everyone involved must remember that
this is an experimental category, so have fun experimenting.

I agree, and also be thinking about the changes a cowl further forward will
change the aerodynamics.

I would think an aerodynamicist would recommend adding some area to the
vertical and horizontal stabilizer, by adding some width and height, or
other profile changes, or extending the length of the fuselage to get a
longer tail moment arms.

I think the Falco probably is designed with the tail areas at close to
minimum areas to maximize performance. If there is area added in front of
the center of pressure, and not compensated with changes behind the center,
you will definitely become a test pilot in another critical way.
--
Jim in NC

On Jun 26, 10:30*pm, Jonny wrote:
There are many aircraft that allow for a variety of engines. Some
engine makers even supply cowling/nose bowl kits for popular types
(Rans, Vans) etc.

So, what do you think of using a Jabiru 5100 (8 cyl) in a Falco in
place of the Lycoming io-360?

Jabiru is narrower and less tall, but is a few inches longer (but
might fit in an unmodified cowling given the different mount design).
Similar power, lighter weight.

I have heard the guys at Sequoia are a bit sensitive about even basic
unseen mods, but what do you guys think?

One other thing to think about is the Jabiru 5100 makes its peak power
at 3300 rpms.. That will drastically reduce the diameter of your
prop to keep the tips from going supersonic.Don't get me wrong, I am a
machinist and that motor is a work of art from the machining
standpoint. A fellow Zenith 801 guy installed the 8 cyl Jabiru and he
didn't factor in the loss of prop diameter, A very needed thing in a
slow flying STOL plane. He still hasn't flown his creation yet but the
numbers say @ 2700 rpms, with a 76" dia prop the Motor will be making
somewhere in the low 140 HP range. I my opinion not enough power for
an 801. If the Sequoia can handle a small diameter prop then this
might be a perfect marriage. PS, I didn't stay in a Holiday Inn
express last night either. :)

Ben
www.haaspowerair.com

I agree, and also be thinking about the changes a cowl further forward will
change the aerodynamics.

In a plane like the Falco I'd also be thinking about the aesthetics!
From that point of view it might be better to put 70 pounds of lead in
the nose and keep the original cowl

One other thing to think about is the Jabiru 5100 makes its peak power
at 3300 rpms.

the numbers say @ 2700 rpms, with a 76" dia prop the Motor will be making
somewhere in the low 140 HP range.


According to Jabiru:

Power Rating
170 hp @ 2700 rpm continuous, 180 hp @ 3000 rpm intermittent

http://www.jabiru.net.au/8%20cylinderbodyFrame-1.htm

On Jun 28, 4:40*am, Michael Henry
wrote:
One other thing to think about is the Jabiru 5100 makes its peak power
at 3300 rpms.
the numbers say @ 2700 rpms, with a 76" dia prop the Motor will be making
somewhere in the low 140 HP range.

According to Jabiru:

Power Rating
170 hp @ 2700 rpm continuous, 180 hp @ 3000 rpm intermittent

http://www.jabiru.net.au/8%20cylinderbodyFrame-1.htm

I stand corrected. When I looked at that engine back a few years ago
@OSH they were claiming 180@3300. They must have lowered their "sweet
spot"...

Ben,

On Jun 28, 5:37 am, Michael Henry
wrote:
I agree, and also be thinking about the changes a cowl further forward will
change the aerodynamics.

In a plane like the Falco I'd also be thinking about the aesthetics!
From that point of view it might be better to put 70 pounds of lead in
the nose and keep the original cowl

Put in a 10 gallon header tank.
Lou