The current rotary engine firewall forward weight is the same > as a
Lycoming O-320 or
O-360.
Most people would have an aft CG problem > at a firewall forward of 250
pounds with a
stock cowl
and prop position. > One would have to move the engine way forward to
get the CG in the >
right
place. If you moved the engine aft in a canard you might > get a prop
strike on flare or
takeoff.
Paul Lamar What is difference in CG position compared to an O320
(ballpark estimate)? I
plan on
mounting as close to the firewall as I can get and still leave room for
accessories and
maintenance access. This is both to avoid the prop strike in my LongEZ,
and to allow me to
move
the battery weight from the nose to the back.
I think I will let others answer that question as it seems to vary
>from installation to installation. Perry's set up is real heavy as he
is using a real flywheel, cast iron exhaust manifold and stock
intake manifold.
Paul Lamar
I don't have any numbers to offer from memory. Yes my engine
installation is probably overweight by at least 75 lbs.
I don't have a cg problem. Engine is mounted as close to the
firewall as practical. With two batteries and a weather radar
in the nose, no cg problem. I can get a number for you if you
wish, distance from firewall to a point on the front of the
engine.
My weight/power condition means it is really only a single
person airplane for long cross-countries when carrying full
fuel. I have taken my 10 year old son on long trips with
as much stuff as I can cram in.
My fan is closer to the firewall than a standard LEZ prop by
a few inches I believe. Prop strike not a concern for me
(just joking).
Perry
"william m dunn, md" wrote:
I would take a light high horsepower ( or high torque ) engine any day over
a heavy one. ANYDAY ! ! !
If cg problems were incurred as a result they could easily be solved in the
Long EZ. Lighter engine equals
greater utility, greater payload, greater fuel load, greater climb rates
etc. Its just less dead weight
you're not hauling around unproductively.
I agree up to this point. But you must realize unless you put it in
an airplane designed for a low HP aircraft engine you will have to
do a major redesign of your typical Lyc O-320 O-360 aircraft.
A low profile rotary weighing 250lbs wet
putting out 200 plus HP would suit me just fine ( more would be better ! ).
Battery in the nose could be moved to the rear
and problem pretty much solved.
Current rotary installation weights are similiar to the weight of the 205 hp
Lycoming 0-360 around 320 lbs wet with accessories. Don't quote me but the
0-320 is quite a bit lighter, say about 60 lbs. The lycoming 0-360 180 hp
version is somewhere between the weight of each.
Just remeber those weights do not include the prop ! It adds up quickly
doesn't it.
I recently saw an animated gif of a rotary in motion but can't seem to find
it. If anyone has a link please forward.
Thanks
bill
The engine itself weighs less than 250 pounds with Tracy's PSRU. It is all the other
stuff around the engine including the prop that goes into the
300 to 330 pound firewall figure number. You will play hell reducing
the weight of all that stuff. When you see a weight quoted for an
air-cooled engine it is likely sans all accessories.
As I mentioned before nobody has a CG problem with a rotary indicating
the installed weight is pretty much the same as a Lyc.
The cast iron end housings are about the only place you are
going to find 50 pounds. If money is no object Racing Beat sells
aluminum end housings to save the magic 50 pounds.
BTW what does torque have to do with it? Airplanes fly on HP.
With a gear box torque is anything you want it to be.
Paul Lamar
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