AVGAS 80 & MOGAS

[Dallas]

My C150M POH shows an approved fuel grade includes AVGAS 80.

Assuming you could find 80, how safe is it to run?

And, what are the modifications made to the fuel system to run MOGAS?

On a purely theoretical level, what would be the ramifications of fueling
up an unmodified Cessna 150 with 92 octane MOGAS?


--
Dallas

[Robert M. Gary]

On Oct 29, 1:42 pm, Dallas > wrote:
> My C150M POH shows an approved fuel grade includes AVGAS 80.
>
> Assuming you could find 80, how safe is it to run?
>
> And, what are the modifications made to the fuel system to run MOGAS?
>
> On a purely theoretical level, what would be the ramifications of fueling
> up an unmodified Cessna 150 with 92 octane MOGAS?
>
> --
> Dallas

Depending on where you live MOGAS may not be approved. Only certain
blends of MOGAS are approved by the FAA and many communities restrict
those blends. .
When I had the Aeronica I found the engine ran much cleaner on 80. It
burns a bit hotter so you get less deposits. The only reason 80 isn't
the preferred gas around the world is because higher compression
engines need the 100.

-Robert

[Gig 601XL Builder]

Dallas wrote:
> My C150M POH shows an approved fuel grade includes AVGAS 80.
>
> Assuming you could find 80, how safe is it to run?
>
> And, what are the modifications made to the fuel system to run MOGAS?
>
> On a purely theoretical level, what would be the ramifications of
> fueling up an unmodified Cessna 150 with 92 octane MOGAS?

Here's some info on a auto fuel STC.

http://autofuelstc.com

[Helen]

You need an STC. I have the EAA one. Just go to their web page. You
can actually burn 87 octone fine on your O200 just make sure it does not
have ethanol in it. Cessna Pilots Associate actually recommends a
mixture of 100LL and AvGas for O200 and O300 engines after break in as
it better approximates the 80 Octane these engines were designed for
that the 100LL you are probably using. It will reduce your fowling
problems and stuck valves, and you won't need to run MMO.

Helen

Dallas wrote:
> My C150M POH shows an approved fuel grade includes AVGAS 80.
>
> Assuming you could find 80, how safe is it to run?
>
> And, what are the modifications made to the fuel system to run MOGAS?
>
> On a purely theoretical level, what would be the ramifications of fueling
> up an unmodified Cessna 150 with 92 octane MOGAS?
>
>

[Dallas]

On Mon, 29 Oct 2007 20:44:44 -0000, Robert M. Gary wrote:

> When I had the Aeronica I found the engine ran much cleaner on 80.

A little research on my own dispelled my incorrect belief that the octane
rating had something to do with the potential power of fuel.

As it turns out, 80 is a pretty good fuel for low compression engines.

Another myth busted.

--
Dallas

[Dallas]

On Mon, 29 Oct 2007 16:47:10 -0500, Gig 601XL Builder wrote:

> Here's some info on a auto fuel STC.
> http://autofuelstc.com

Very informative... thanks.

--
Dallas

[Ron Natalie]

Dallas wrote:
> My C150M POH shows an approved fuel grade includes AVGAS 80.
>
> Assuming you could find 80, how safe is it to run?
>
> And, what are the modifications made to the fuel system to run MOGAS?
>
> On a purely theoretical level, what would be the ramifications of fueling
> up an unmodified Cessna 150 with 92 octane MOGAS?
>
>
Low compression engines work well on 80 octane. The problem with 100LL
is that you don't need the extra octane (does nothing for you) but you
also don't want all the extra lead. 100LL is only "low" in lead
compared to the old 100/130 fuel it replaced. It has 4 times the lead
that 80 did and way more than premium auto gas ever did.

The only problem is the corn lobby is making it pretty darned difficult
to find autofuel without ethanol in it and ethanol is not approved for
the autofuel STC's (and it plays hell on us boaters too!)

[Robert M. Gary]

On Oct 29, 6:31 pm, Helen > wrote:
> You need an STC. I have the EAA one.

I used to too. However, do you find many places that still has legal
autogas? In California it seems all the gas has the prohibited
ethanol. With the liberal states requiring ethanol to starve the
Mexicans from their tortillas and the midwester states requiring it to
boast their own pockets it doesn't seem like anyone is left with old
fashion, FAA approved, mogas.

-Robert

[Jay Honeck]

> I used to too. However, do you find many places that still has legal
> autogas? In California it seems all the gas has the prohibited
> ethanol. With the liberal states requiring ethanol to starve the
> Mexicans from their tortillas and the midwester states requiring it to
> boast their own pockets it doesn't seem like anyone is left with old
> fashion, FAA approved, mogas.

No problem getting unpolluted, ethanol free gas here in Iowa,
ironically the source of most ethanol.

Mary and I are about to pass 9,000 gallons of trouble-free mogas usage
in our Cherokee(s), all dispensed from our Mighty Grape fuel hauler.
At the current price differential of $2.25+ per gallon, using mogas
will have paid for my next engine...
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[J. Severyn]

----- Original Message -----
From: "Jay Honeck" >
Newsgroups: rec.aviation.piloting
Sent: Tuesday, October 30, 2007 10:22 AM
Subject: Re: AVGAS 80 & MOGAS


>
> No problem getting unpolluted, ethanol free gas here in Iowa,
> ironically the source of most ethanol.
>


Yep.....Jay, every time I think about the corn states exporting their lousy
fuel to other states, and not using it locally, it tics me off. I put over
1500 hours on a Lyc with a Peterson STC, and that was the best fuel for that
engine.....bar none. The plugs were clean, the oil remained clean 2-3 times
longer etc. But alas....now mogas in our area all has alcohol, so now I
clean plugs and change oil more often......and of course pay the higher
price for 100LL. Oh well...

John Severyn
@KLVK Livermore, Ca.

[RST Engineering]

Modesto CA still has legal mogas. THe catch is that they have to take it
8000 gallons at a time (full tanker load).

The alcohol is blended into the gasoline right at the tanker load spigot and
"mixed" with the tanker sloshing it all around on the trip to your local gas
station, so all they have to do is turn off the alcohol switch and the whole
damned load is alky free. But, as I said, you have to take a full tanker
load of it and most airports can't afford to do that.

Jim

--
"If you think you can, or think you can't, you're right."
--Henry Ford

"Robert M. Gary" > wrote in message
ups.com...
> On Oct 29, 6:31 pm, Helen > wrote:
>> You need an STC. I have the EAA one.
>
> I used to too. However, do you find many places that still has legal
> autogas? In California it seems all the gas has the prohibited
> ethanol. With the liberal states requiring ethanol to starve the
> Mexicans from their tortillas and the midwester states requiring it to
> boast their own pockets it doesn't seem like anyone is left with old
> fashion, FAA approved, mogas.
>
> -Robert
>

[Morgans[_2_]]

"RST Engineering" > wrote

> But, as I said, you have to take a full tanker load of it and most
> airports can't afford to do that.

Are they allowed to have two or three airports share a full load?
--
Jim in NC

[RST Engineering]

Dunno.

Jim

--
"If you think you can, or think you can't, you're right."
--Henry Ford

"Morgans" > wrote in message
...
>
> "RST Engineering" > wrote
>
>> But, as I said, you have to take a full tanker load of it and most
>> airports can't afford to do that.
>
> Are they allowed to have two or three airports share a full load?
> --
> Jim in NC
>
>

[Blueskies]

"Robert M. Gary" > wrote in message oups.com...
> On Oct 29, 1:42 pm, Dallas > wrote:
>> My C150M POH shows an approved fuel grade includes AVGAS 80.
>>
>> Assuming you could find 80, how safe is it to run?
>>
>> And, what are the modifications made to the fuel system to run MOGAS?
>>
>> On a purely theoretical level, what would be the ramifications of fueling
>> up an unmodified Cessna 150 with 92 octane MOGAS?
>>
>> --
>> Dallas
>
> Depending on where you live MOGAS may not be approved. Only certain
> blends of MOGAS are approved by the FAA and many communities restrict
> those blends. .


Only if the airplane has the STC. If no STC, mogas is not approved...

[Orval Fairbairn]

In article >,
"Blueskies" > wrote:

> "Robert M. Gary" > wrote in message
> oups.com...
> > On Oct 29, 1:42 pm, Dallas > wrote:
> >> My C150M POH shows an approved fuel grade includes AVGAS 80.
> >>
> >> Assuming you could find 80, how safe is it to run?
> >>
> >> And, what are the modifications made to the fuel system to run MOGAS?
> >>
> >> On a purely theoretical level, what would be the ramifications of fueling
> >> up an unmodified Cessna 150 with 92 octane MOGAS?
> >>
> >> --
> >> Dallas
> >
> > Depending on where you live MOGAS may not be approved. Only certain
> > blends of MOGAS are approved by the FAA and many communities restrict
> > those blends. .
>
>
> Only if the airplane has the STC. If no STC, mogas is not approved...

There are two STCs involved:
1. Engine STC, verifying that the engine in question can safely run on
it.

2. The installation STC, which verifies that you will not get vapor lock.
In this case, a gravity-fed system has a major advantage.
For more than a one-off approval, you have to load the tank with 110F
fuel and climb to 10,000 feet to prove tha no vapor lock problems are
there. Sometimes an additional boost pump is required.

[[email protected]]

On Oct 30, 3:31 am, Helen > wrote:
> Cessna Pilots Associate actually recommends a
> mixture of 100LL and AvGas for O200 and O300 engines after break in as
> it better approximates the 80 Octane these engines were designed for
> that the 100LL you are probably using. It will reduce your fowling
> problems and stuck valves, and you won't need to run MMO.

We used to do that with our flight training airplanes. 75% mogas
and 25% 100LL to approximate the lead content of the old 80/87. But it
didn't work. We had sticking valves and worn valve guides. After we
went to straight 100LL the problems disappeared and we got plug
fouling instead, but that's a lot more manageable than top overhauls
halfway to TBO.
Unleaded mogas today is made differently than the leaded stuff was
years ago. Instead of boiling the crude and condensing the various
fractions at the different temperatures to get the fractions needed to
mix a batch of fuel, they disassemble the stuff on the molecular level
with catalysts or something and reassemble it into unleaded mogas. The
result is something rather different than leaded gasoline and some
engine components don't like it. Too "dry" or something. A major
rebuilder we deal with says they encounter considerable wear in
mogassed engines.
That's how I understand it, anyway. Some folks use mogas
exclusively and seem to have no trouble. We couldn't stick with it.

Dan

[RST Engineering]

Sorry, that's an OWT. 80/87 had a MAXIMUM of 0.5 ml TEL per gallon. In
fact, due to the cost of the TEL and the ease of refining 80 octane gas
after WWII, 80 had zero lead.

Jim



> We used to do that with our flight training airplanes. 75% mogas
> and 25% 100LL to approximate the lead content of the old 80/87. But it
> didn't work. We had sticking valves and worn valve guides.>

[Big John]

Jim

Most tankers have multiple tanks. For example a 8000 gallon tank truck
could have four 2000 gallon tanks. This lets them deliver smaller
amounts of gas to the small Stop & Go type stores that don't want to
invest the dollars in a full load all at one time.

The multiple tanker layout is also a safety feature so that if one
tank starts a leak only part of the load will get out (small possible
fire and clean up and less money lost). Also it lets the tanker carry
different grades of gas (reg, super, extra $ super) on one delivery to
a station.

So, I see no problem (from experience a number of years ago in the gas
business) of dropping less than the full tanker at different
locations.

Only thing might be cost of tanker charge for the extra distance and
time needed to hit several locations??? Also it assumes that several
airports all needed gas at same time so one tanker could hit them all
with the total load of 8000 gallons.

Have a nice day in the land of F's & N's. Only spent 7 wonderful years
flying out there before SF went to the 'F's' :o)

Big John

************************************************** ***********


On Tue, 30 Oct 2007 15:50:50 -0700, "RST Engineering"
> wrote:

>Dunno.
>
>Jim

[Morgans[_2_]]

"Big John" > wrote

> Most tankers have multiple tanks. For example a 8000 gallon tank truck
> could have four 2000 gallon tanks. This lets them deliver smaller
> amounts of gas to the small Stop & Go type stores that don't want to
> invest the dollars in a full load all at one time.
>
> The multiple tanker layout is also a safety feature so that if one
> tank starts a leak only part of the load will get out (small possible
> fire and clean up and less money lost). Also it lets the tanker carry
> different grades of gas (reg, super, extra $ super) on one delivery to
> a station.

Also, it is VERY important to have dividers in a large tanker, so when you
are putzing about with a third of a load, that you don't have the whole load
shift to the front at one time, or back, or whatever.
--
Jim in NC

[Ron Natalie]

Morgans wrote:

>
> Also, it is VERY important to have dividers in a large tanker, so when you
> are putzing about with a third of a load, that you don't have the whole load
> shift to the front at one time, or back, or whatever.

The tanks will have baffles in ADDITION to the tank segregation. Even
2000 gallons is more than you want to slosh around uncontrolled.

[Morgans[_2_]]

"Ron Natalie" > wrote in message
m...
> Morgans wrote:
>
>>
>> Also, it is VERY important to have dividers in a large tanker, so when
>> you are putzing about with a third of a load, that you don't have the
>> whole load shift to the front at one time, or back, or whatever.
>
> The tanks will have baffles in ADDITION to the tank segregation. Even
> 2000 gallons is more than you want to slosh around uncontrolled.

Of course. Baffles will still let all of the liquid flow to one part of the
tank, or the other. It does let it flow much more slowly, and predictably,
so it is not as much of a problem, though.
--
Jim in NC

[Dana M. Hague]

Back in the 1980's when I still had my 1941 T-Craft (which had an A-65
and ran fine on the leaded regular mogas which was still available at
a few stations then), I looked at the type certificate and all it said
was "73 octane minimum". Never was clear whether that meant mogas was
legal even without an STC.

-Dana

--
--
If replying by email, please make the obvious changes.
-------------------------------------------------------------------------------
Southern DOS: Y'all reckon? (Yep/Nope)

[Bertie the Bunyip[_19_]]

Dana M. Hague <d(dash)m(dash)hague(at)comcast(dot)net> wrote in
:

> Back in the 1980's when I still had my 1941 T-Craft (which had an A-65
> and ran fine on the leaded regular mogas which was still available at
> a few stations then), I looked at the type certificate and all it said
> was "73 octane minimum". Never was clear whether that meant mogas was
> legal even without an STC.
>

Well, kinda. Avgas was only relatively new when tha airplane was made. Most
antiquers today shy away from avgas if at all possible (I'm talking about
guys running early Wrights and Kinners and so on now) My LeBlond specifies
a minimum of 60 octane, which is basically carrot juice and doesn't like
lead at all..There was an Avgas, before my time, that was a levle below 80.
90 was still available, though scare, when I started and I have seen
115/145 not all that long ago in places that DC7s and what not were still
frequenting and any place the US Navy was still operating P-2 s in earnest
like Keflavik.
IIRC the 115/145 was purple, the 90/98 was blue and the 70ish octane stuff
was brownish yellow, but never having seen it I only knew that from
whatever books or lists still carried that info.
But the little pre-war designed flat fours were widely run on mogas after
80 started getting scarce, STC or no STC. The FAA doesn't seem to be too
bothered about it.



Bertie

[Big John]

Go to:

http://books.google.com/books?id=QhEaoGYT4FIC&pg=PA10&lpg=PA10&dq=73+octane+gasoline&source=web&ots=cs-QbiyWZ5&sig=p5nvof9JeDo05J4dYfkqHeKUVPA#PPP1,M1

Checked this URL and works for me from this posting.

Good info on aircraft fuels from 30's on.

Big John

********************************************


On Thu, 8 Nov 2007 03:51:48 +0000 (UTC), Bertie the Bunyip >
wrote:

>Dana M. Hague <d(dash)m(dash)hague(at)comcast(dot)net> wrote in
:
>
>> Back in the 1980's when I still had my 1941 T-Craft (which had an A-65
>> and ran fine on the leaded regular mogas which was still available at
>> a few stations then), I looked at the type certificate and all it said
>> was "73 octane minimum". Never was clear whether that meant mogas was
>> legal even without an STC.
>>
>
>Well, kinda. Avgas was only relatively new when tha airplane was made. Most
>antiquers today shy away from avgas if at all possible (I'm talking about
>guys running early Wrights and Kinners and so on now) My LeBlond specifies
>a minimum of 60 octane, which is basically carrot juice and doesn't like
>lead at all..There was an Avgas, before my time, that was a levle below 80.
>90 was still available, though scare, when I started and I have seen
>115/145 not all that long ago in places that DC7s and what not were still
>frequenting and any place the US Navy was still operating P-2 s in earnest
>like Keflavik.
>IIRC the 115/145 was purple, the 90/98 was blue and the 70ish octane stuff
>was brownish yellow, but never having seen it I only knew that from
>whatever books or lists still carried that info.
>But the little pre-war designed flat fours were widely run on mogas after
>80 started getting scarce, STC or no STC. The FAA doesn't seem to be too
>bothered about it.
>
>
>
>Bertie

[JGalban via AviationKB.com]

Bertie the Bunyip wrote:
>IIRC the 115/145 was purple, the 90/98 was blue and the 70ish octane stuff
>was brownish yellow, but never having seen it I only knew that from
>whatever books or lists still carried that info.

Hey, you left out 100/130 green gas. I actually found an FBO in Montana
selling this stuff a few years ago. They said they carried it mostly for
supplying old, turbocharged radials on the firebombers in the summertime.

Whenever I'd tell the desk to top me off with avgas, they'd ask, "Blue or
green?".

John Galban=====>N4BQ (PA28-180)

--
Message posted via http://www.aviationkb.com

[Bertie the Bunyip[_19_]]

"JGalban via AviationKB.com" <u32749@uwe> wrote in
news:7aed1bb2bf956@uwe:

> Bertie the Bunyip wrote:
>>IIRC the 115/145 was purple, the 90/98 was blue and the 70ish octane
>>stuff was brownish yellow, but never having seen it I only knew that
>>from whatever books or lists still carried that info.
>
> Hey, you left out 100/130 green gas. I actually found an FBO in
> Montana
> selling this stuff a few years ago. They said they carried it mostly
> for supplying old, turbocharged radials on the firebombers in the
> summertime.
>
> Whenever I'd tell the desk to top me off with avgas, they'd ask,
> "Blue or
> green?".


Yeah, that's right. The blue 100LL didn;t come around until the late 70s.
The early atches had some serious problems with hygroscopy and I nearly met
my end from this as did a friend of mine.
Also it smells like hell.



Bertie