SLOL/LSA Expectations

"aerojones" wrote in message ...

Hi

I'm conducting a survey for my aeronautics course and I was hoping you
all could help me out.

I'm focusing on smaller single reciprocating, nonturbine engine
aircrafts and I wanted to know what are the most important
features/expectations when considering a STOL and/or Light Sport
aircraft? Whether you are looking to buy, build, or just fly.

Any and all opinions are appreciated. Thanks




--
aerojones

price
Safety
usability (ie flyable in moderate wind)
standard parts (lower cost of ownership)

Morgans wrote:
"Rocky" wrote

I am going to use a Suzuki 1300cc (70 hp) with a belt reduction unit.
I had a Samurai for 14 years with this exact engine in it.
On the freeway its almost full throttle and turning 36- 3800 RPM hour
after hour.
Will be the same RPM in the plane at cruise.
All up engine wt is about 50 lbs LESS than the VW.
I am still welding the fuse so have few pics
Sounds cool. I would love to see it, if and when you put some pictures
somewhere we can see them.

I have to admit having given that engine some consideration. Now, I have
been thinking about the Chevy engine they are putting in the Cobalts. They
have a model that is turbocharged that would make a really cool turbo
normalized setup. Good thing, if you put it into a LSA, and put a steep
enough prop to keep it under speed at low altitudes, and let it crank up at
altitude. Zoom! g


I wonder how the final cost and weight would compare to a Rotax 914???

On Feb 4, 4:36*am, cavelamb wrote:

I wonder how the final cost and weight would compare to a Rotax 914???

Based on a quick internet search the Rotax is about 40 pounds less and
between 2 and 3 times the price.

http://www.ultralightnews.ca/rotaxengineprices/6.html
http://www.raven-rotor.com/
http://www.rotaxservice.com/rotax_en...tax_914ULs.htm

I can second the statement that the 1300 in a Samurai is operated at
an aircraft power profile while on the interstate. Pedal to the floor
and shift down on hills when the rpm drops below peak torque is normal
operating procedure. In my case it was a necessity to keep the speed
up. Dropping below 60 meant the onset of divergent shimmy about the
lateral axis until the speed dropped below 40 or so.

As for the original thread -

Along with being reasonable to purchase and operate, implying a "take
home" plane, it should not be so fragile that ground handling becomes
a problem.

Another factor that I think is going to become even more
important ............. it should have a power plant that can operate
on standard auto fuel - alcohol and all. If snowmobiles and 4
wheelers can operate at 14,000+ ft density altitudes on auto fuel
there must be a way to make LSA's do the same?
===========================
Leon McAtee

On Feb 3, 6:32 pm, "Morgans" wrote:
wrote

3600 or 3800 RPM on the highway is a LOT different than
3600-3800 in the air. The highway vehicle is using about 25-35% of its
power capacity. Its throttle is maybe half open at the most. Check
yours again and see. In the airplane, 75% is more like it and the
throttle is three-quarters of the way open.

Not necessarly true in the case of the Sameri. It is a boxy little car,
with tons of drag, and a little engine. He said it was near wide open, and
that would not surprise me.

That said, Raven Redrives have a couple of Suzuki conversions.

It seems to have proven itself, fairly well, in airplanes.
--
Jim in NC

I should have addressed the RPM issue a little further. What's
the redline RPM of that engine? Around 6000, I think. So at 36 or 3800
RPM, even at full throttle, we're not pushing it to anywhere near max
power output, which we'd prefer from such a tiny engine in an
airplane. We might be getting max torque from it, but HP consists of
both torque and RPM, and at high RPM and full throttle there will be
much more stress on the engine and more waste heat generated.
Raven says they run theirs at around 4000 so they're giving up
some power in the interest of longevity, but they end up with a poorer
power-to-weight ratio.

Dan

wrote in message
...
As for the original thread -

Along with being reasonable to purchase and operate, implying a "take
home" plane, it should not be so fragile that ground handling becomes
a problem.

Another factor that I think is going to become even more
important ............. it should have a power plant that can operate
on standard auto fuel - alcohol and all. If snowmobiles and 4
wheelers can operate at 14,000+ ft density altitudes on auto fuel
there must be a way to make LSA's do the same?
===========================
Leon McAtee

The more frustrating problem might be to make it run on av-gas, although
echanics have also told me that may be a non-issue as well. Basically, if
you are willing to accept the as delivered reliability of the automotive
FADEC systems, which have become very good, then the primary issue would be
lead fouling of the oxigen sensor--the the mechanics have told me that the
oxigen sensors do not fail in the conventional sense, due to lead fouling;
but only become slow in their operation. Since aircraft engines are
normally operated at continuous output levels, and the FADEC systems are
capable of operating with enriched mixture in open-loop mode when at maximum
power and also while the oxigen sensor catches up, the lead fouling problem
may be trivial in most cases.

Just a thought, for what it's worth and withh the understanding that I am
not really taking a position. In fact, there appears to be mounting
evidence that the total cost of a conversion might not be much of a saving
over the purpose built aircraft engines.

Peter

"cavelamb" wrote

I wonder how the final cost and weight would compare to a Rotax 914???

It could be as much as a boat anchor more than a Rotax 914, and twice the
cost, and I would still prefer it.
--
Jim in NC

Peter Dohm wrote:
... if
you are willing to accept the as-delivered reliability of the automotive
FADEC systems, which have become very good, then the primary issue would be
lead fouling of the oxygen sensor...
Peter


Yes.
It is not contentious to mention that the longevity of auto engines has
increased by leaps and bounds since the advent of FADECs.
Longevity does not equate to reliability exactly, but electronic
ignition has been helpful, I believe crucial in fact, and mechanical
design of self adjusting lifters is no longer a black-art. It seems to
me that the water-cooled engine can be made to cope with the high
rejected-heat associated with high throttle operation. There is still a
question in my mind about the heat-shedding arrangements for lube oil
but an oil radiator is nothing new, and exhaust valves would benefit
from some premium qualities.

Brian W

Morgans wrote:
"cavelamb" wrote

I wonder how the final cost and weight would compare to a Rotax 914???

It could be as much as a boat anchor more than a Rotax 914, and twice the
cost, and I would still prefer it.


Care to share the "why", Morgans?

I've flown the 912 and liked it a lot.
Haven't had the opportunity to fly a 914 tho.

On Feb 4, 6:16*pm, Brian Whatcott wrote:
Peter Dohm wrote:
... if
you are willing to accept the as-delivered reliability of the automotive
FADEC systems, which have become very good, then the primary issue would be
lead fouling of the oxygen sensor...
Peter

* Yes.
It is not contentious to mention that the longevity of auto engines has
increased by leaps and bounds since the advent of FADECs.
Longevity does not equate to reliability exactly, but electronic
ignition has been helpful, I believe crucial in fact, and mechanical
design of self adjusting lifters is no longer a black-art. *It seems to
me that the water-cooled engine can be made to cope with the high
rejected-heat associated with high throttle operation. There is still a
question in my mind about the heat-shedding arrangements for lube oil
but an oil radiator is nothing new, and exhaust valves would benefit
from some premium qualities.

Brian W

You are right in your thoughts,,, I fly one almost every day to prove
your point....


Ben
www.haaspowerair.com

http://video.google.com/videoplay?do...50730841&hl=en