MOGAS availability database

"Dave Stadt" wrote in message
...


You probably already know, but that 25% that needs 100LL is the bunch
that
flies 75% (or so) of the hours each year.

I would need to see something to support that. The 100LLers are the high
performance engines which in my experience sit in the hangar. Given, on
those few occasions when they do venture out they burn a lot of gas.

AOPA GA Fact Sheet:

"General Aviation aircraft flew an average of 144 flight hours each in 1997,
but considerable differences existed within the fleet: the average for all
piston aircraft was 133 hours (131 hours for piston singles, 149 for
multiengine pistons); 295 hours for turboprops; 331 hours for jets; and 307
hours for rotorcraft."

Also, the higher performance aircraft are used in a lot of cargo hauling and
air taxi...they fly a lot.

Then too, while it's anecdote, John Deakin says "The owners of the 70% of
the airplanes that burn 30% of the fuel will yell, "Give us a low octane
fuel we can use, and find something else for those other guys." Two fuels
isn't going to work — the two-fuel infrastructure is no longer there." I'd
say he's a lot closer to the industry than you or I.

"Jay Honeck" wrote in message
news:xnpce.26236$c24.21401@attbi_s72...
I would need to see something to support that. The 100LLers are the
high
performance engines which in my experience sit in the hangar.

Agreed -- although offsetting that are the air charters that fly many
hours
on end. I believe they are skewing the numbers dramatically.

Not to mention the cargo/package haulers. Every night, out and back.

At my field, private twins and truly high performance birds rarely leave
their hangars. What we see flying all day long, day in and day out, are
the
C-150s and Cherokee 140s -- both of which could be (and possibly already
are) running on mogas.

Get into an airport that supports a lot of commerce and you'll see a lot of
difference from the smaller town recreational flyers. I see the
recreational/personal flyers go out and fly an hour or so, but the business
users I know (Cessna 3xx, 4xx, 210's, Barons, Bonanzas, etc) are doing two
and three hour flights at least a couple times a month to a couple times a
week.

I hear so many people in here that put 50-100 hours a year on their planes.
I put over 380 hours on my airplane last year; 310 for business and 70 for
personal.

I'm guessing, Jay, that a lot of people you know with high performance
aircraft mainly use them for personal flying. Fly into a Denver/Centennial
or Jeffco, Grand Junction, or the reliever airports around Dallas, or San
Antonio and you'll see a very different composition. I also fly into a lot
of out-of-the-way places and the difference is striking.


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

He's right... I wanna say I saw it in a column on Avweb.. regarding the
"demise" of 100LL.

I think it was a Deakin or Busch Column..

And it was to the effect of the 25% of the fleet that REQUIRES 100LL is
the part that burns 75% of the refined fuel. Keep in mind these are the
higher compression, higher horsepower, sometimes turboed engines..
usually on twins.. doing commercial stuff.

Dave

Dave Stadt wrote:
"Matt Barrow" wrote in message
...

"Dave Stadt" wrote in message
om...

More engines are mogas capable than those that need 100LL. If 100LL

were

to

disappear the vast majority of the fleet would get along just fine on

mogas.

In fact the majority of the fleet is much better off burning mogas.


You probably already know, but that 25% that needs 100LL is the bunch that
flies 75% (or so) of the hours each year.


I would need to see something to support that. The 100LLers are the high
performance engines which in my experience sit in the hangar. Given, on
those few occasions when they do venture out they burn a lot of gas.

Sounds good, Dave. The ECU sounds like the MegaSquirt or one of it's
derivatives. However, how will you solve the O2 sensor problem? Maybe
you could use history data to maintain the fuel/air ratios?



Dave S wrote:

You are presuming that I am going to use the stock ECU (engine control
unit)..which is the last thing I would do. Stock ECU's do strange and
unpredictable things like turn off (or power down) the engine to
"protect" it when sensor readings get out of spec (like oil temp or
pressure parameters, etc)

The issue of ECU's have been discussed EXTENSIVELY in the forums that I
frequent: one is a list-serv dedicated to rotary engines, and the other
is a canard forum with a rotary engine portion. If you were a member
there you could spend hours and still not cover all the material, some
practical and some theoretical.

The ECU we will be using will be able to tune/make program adjustments
to the fuel map, but once programmed can operate without input from the
sensor.

Also, the neat thing about the Mazda rotary is.. no valves.

Dave

AINut wrote:

All of the dozen or so airports I've contacted about mogas only have
87 octane. All are considerably higher priced than the most expensive
gas station.

If you use 100ll in an engine that has valves designed for no lead
usage, you're probably going to lose that engine. Also, the O2
sensors will clog with lead very shortly. A propane torch can burn
the lead off it but you'll have to remove all the O2 sensors to do
that. If the O2 sensors clog up during flight, the engine computer
will go into limp home mode. This usually means a *drastic* cut in
horsepower, sometimes engine stoppage.

HTH.



Dave S wrote:



Rich S. wrote:
Make that last idea a *must*, Dave. You don't know what you are
getting out

of a strange mogas tank. It may be 100° out and that mogas could've
been sitting in the tank since winter. My commandments read:
1. Never use mogas from an unfamiliar source.
2. Always test for alcohol.
3. Never use mogas above 5,000' density altitude.
4. Always check for water.
5. Never use mogas above 80° F.

Remember - 100 LL can foul a spark plug. Mogas can boil, give you
vapor lock, and stop your engine RFN. Which would you prefer? Would
you like fries with that?

Rich S.




Dude... I'm using mogas because I'm using a MO-engine. I've driven
cars at over 5000 ft (Lake Tahoe.. 9000 ft) MSL.. and in temps over
100* F... and alcohol wont hurt MY engine because the seals in it and
the fuel system are DESIGNED to use motor gas in all of its domestic
forumulations. I think some of those "absolutes" you are listing are
overkill.

I will be using fuel injected engine with an automotive fuel rail
regulated at 40 PSI over upper deck pressure..through a recirculating
fuel circut with firesleeved hoses. I don't think vapor lock is gonna
be the issue here. I'm just planning on using 100LL because I dont
want to land on a 2000 ft sod strip 40 miles from the nearest town of
over 50,000 people. I'm into flying to travel to where the people are

One thing that really bothers me (and I don't have a practical answer
for it yet) is that mogas will degrade significantly over just a short
period of time. If I let the plane sit for months (gasp!) before using
it again, I'd be extremely worried about the fuel quality. Avgas has
additives that remove that problem. I tried sta-bil in my lawn mower as
a test and had to toss that engine 8-(.



Peter Duniho wrote:

"Rich S." wrote in message
...

[...]
Gas that is not blended for altitude and or season (temperature) can make
the fan stop turning. In your car, you likely bought gas that was intended
for use at Lake Tahoe and/or in temps over 100° F.


That's silly. We have driven a Suburban, with its 42 gallon tank, all over
the US, including Lake Tahoe. We bought the fuel we rode into Tahoe on at
least 500 miles away, not far above sea level, in the desert. Many times,
fuel purchased in one locale took us right into a place with completely
different characteristics (altitude, temperature, whatever).

I wouldn't be surprised to find there are road vehicles with even greater
range (the actual range of our Suburban is about 800 miles, but we didn't
roll into Lake Tahoe on fumes, of course). In fact, I'm pretty sure the
hybrids do, and I know at least two that have been driven on long trips.
Never heard any complaints about gas troubles there either.

I've seen the "well, but the auto gas is specially formulated for the region
in which it's sold" line before. It just doesn't hold up to common sense
and personal experience. If the gas *is* specially formulated, then using
it in the "wrong" place certainly doesn't cause anything so serious as
engine stoppage, or even any significant performance difference (ie,
noticeable by the driver).

Pete

AINut wrote:

One thing that really bothers me (and I don't have a practical answer
for it yet) is that mogas will degrade significantly over just a short
period of time. If I let the plane sit for months (gasp!) before using
it again, I'd be extremely worried about the fuel quality. Avgas has
additives that remove that problem. I tried sta-bil in my lawn mower as
a test and had to toss that engine 8-(.

And I just fired up my lawn mower with last years gas a couple weeks
ago. I had about 3 gallons that was left sitting in the shed over the
winter, fill up the mower and on about the third pull she fired right
up. Probably bought that gas in August or September.

Newps wrote:


AINut wrote:

One thing that really bothers me (and I don't have a practical answer
for it yet) is that mogas will degrade significantly over just a short
period of time. If I let the plane sit for months (gasp!) before
using it again, I'd be extremely worried about the fuel quality.
Avgas has additives that remove that problem. I tried sta-bil in my
lawn mower as a test and had to toss that engine 8-(.


And I just fired up my lawn mower with last years gas a couple weeks
ago. I had about 3 gallons that was left sitting in the shed over the
winter, fill up the mower and on about the third pull she fired right
up. Probably bought that gas in August or September.

Yep... as they say, your mileage may vary.

A few years ago, before I went away for six months, I put some
sta-bil in my car's gas tank and filled it up with regular gas. I
had a friend come over and start it every month or so and run it for
a few minutes, but other than that it sat. When I got home, it ran a
bit rough for the first couple minutes and fine after that.

http://www.rotaryaviation.com/eficont.html

Its sitting in the box at the hangar.. just need to fabricate a custom
intake. The EFI runs off of a MAP sensor and and the stock crankshaft
position sensor (which derives RPM and ingnition timing points). Two
programming maps (data table): One is under load, and the other is for
low load/high RPM (such as in a descent).

No MAF's, No Throttle Position Sensors, No use of the oxygen sensor is
REGULAR use, only in programming the fuel maps (data table). Brutally
simple, but the aircraft mode of operation is pretty simple as well.

Dave

AINut wrote:
Sounds good, Dave. The ECU sounds like the MegaSquirt or one of it's
derivatives. However, how will you solve the O2 sensor problem? Maybe
you could use history data to maintain the fuel/air ratios?



Dave S wrote:

You are presuming that I am going to use the stock ECU (engine control
unit)..which is the last thing I would do. Stock ECU's do strange and
unpredictable things like turn off (or power down) the engine to
"protect" it when sensor readings get out of spec (like oil temp or
pressure parameters, etc)

The issue of ECU's have been discussed EXTENSIVELY in the forums that
I frequent: one is a list-serv dedicated to rotary engines, and the
other is a canard forum with a rotary engine portion. If you were a
member there you could spend hours and still not cover all the
material, some practical and some theoretical.

The ECU we will be using will be able to tune/make program adjustments
to the fuel map, but once programmed can operate without input from
the sensor.

Also, the neat thing about the Mazda rotary is.. no valves.

Dave

AINut wrote:

All of the dozen or so airports I've contacted about mogas only have
87 octane. All are considerably higher priced than the most
expensive gas station.

If you use 100ll in an engine that has valves designed for no lead
usage, you're probably going to lose that engine. Also, the O2
sensors will clog with lead very shortly. A propane torch can burn
the lead off it but you'll have to remove all the O2 sensors to do
that. If the O2 sensors clog up during flight, the engine computer
will go into limp home mode. This usually means a *drastic* cut in
horsepower, sometimes engine stoppage.

HTH.



Dave S wrote:



Rich S. wrote:
Make that last idea a *must*, Dave. You don't know what you are
getting out

of a strange mogas tank. It may be 100° out and that mogas could've
been sitting in the tank since winter. My commandments read:
1. Never use mogas from an unfamiliar source.
2. Always test for alcohol.
3. Never use mogas above 5,000' density altitude.
4. Always check for water.
5. Never use mogas above 80° F.

Remember - 100 LL can foul a spark plug. Mogas can boil, give you
vapor lock, and stop your engine RFN. Which would you prefer? Would
you like fries with that?

Rich S.





Dude... I'm using mogas because I'm using a MO-engine. I've driven
cars at over 5000 ft (Lake Tahoe.. 9000 ft) MSL.. and in temps over
100* F... and alcohol wont hurt MY engine because the seals in it
and the fuel system are DESIGNED to use motor gas in all of its
domestic forumulations. I think some of those "absolutes" you are
listing are overkill.

I will be using fuel injected engine with an automotive fuel rail
regulated at 40 PSI over upper deck pressure..through a
recirculating fuel circut with firesleeved hoses. I don't think
vapor lock is gonna be the issue here. I'm just planning on using
100LL because I dont want to land on a 2000 ft sod strip 40 miles
from the nearest town of over 50,000 people. I'm into flying to
travel to where the people are

Jay Honeck wrote:

What we see flying all day long, day in and day out, are the
C-150s and Cherokee 140s -- both of which could be (and possibly already
are) running on mogas.

In many cases, you don't see the perfomance birds because they takeoff and go
somewhere. They're putting lots of hours in, but they aren't shooting T&Gs like
the bug-smasher crowd is.

George Patterson
There's plenty of room for all of God's creatures. Right next to the
mashed potatoes.

Newps wrote:


And I just fired up my lawn mower with last years gas a couple weeks
ago.

Well, I just fired mine up with last year's gas too. Almost made one circuit
around the yard before it developed spasms and limped back to it's home under
the porch.

I'll be draining the gas tomorrow.

George Patterson
There's plenty of room for all of God's creatures. Right next to the
mashed potatoes.