Lycoming to approve 93 octane auto gas for O-360 & IO-360

Come on people! Wide areas of the country have access to alcohol-
free auto fuel. Usually it is a premium major brand source. It is
widely used at marinas and is also available to airports that take the
effort to request it from their suppliers.

"David L" wrote...
> There is no real reason that FBO's can not get un-tainted
> gasoline. The alcohols are added in when the truck is filled.
> The difficulties are procedural not strategic...

Yes and no. Most trucks have residual when they return to the farm to
refill. Since most FBOs can't take the entire trailer, they will pay a
premium to the trucking firm for a dedicated partial load. That markup is
more than a few cents (more like 10 to 50 cents) per gallon, and then you'll
still get a small mix of residual.

The FBO is also not taking a trailer (or seven) a week, so every run is a
special. That means the trucking co will fit the FBO in with no guarantees.
So the FBO will need to schedule early (so as not to run out) and therefore
will take even a smaller load. Sometimes the load is so small the FBO will
have to take a mini, making the FBO pay for gas not taken.

Also, many of the Quicky Marts make more profits from the food and coffee,
than from the gas pumped. The FBO will not sell at such small margins, so
all said and done the Mogas will likely be a dollar to 1.50 higher than the
Quicky Mart. Now add in what Kyle B mentioned about the Mogas cutting into
the FBOs Avgas sales and it's a loser all around (for the FBO).

Damn those pesky details!

On Jun 9, 5:16 pm, David Lesher <wb8...@panix.com> wrote:
> "JGalban via AviationKB.com" <u32749@uwe> writes:
>
> >   If you're O-360 happens to be in a Cherokee, you can already get an auto
> >gas STC.  Otherwise, I wouldn't hold my breath on this Lycoming move.  The
> >autogas spec they're trying to get approved can contain oxygenates (mainly
> >ethanol, now that MTBE is gone).  
>
> There is no real reason that FBO's can not get un-tainted gasoline. The
> alcohols are added in when the truck is filled. The difficulties are
> procedural not strategic...
>
> --
> A host is a host from coast to coast.................wb8...@nrk.com
> & no one will talk to a host that's close........[v].(301) 56-LINUX
> Unless the host (that isn't close).........................pob 1433
> is busy, hung or dead....................................20915-1433

That's the line I was thinking along. There are maybe a couple of
refineries making avgas. A very limited market. The rest are making
auto gas and blending it before delivery to the local quick mart. If
you wanted it unblended I don't think it would be a big problem. I can
see the problem Dave mentioned for the FBOs. Not sure how that will
play out.

Regards,
Bud

Mike Isaksen wrote:
> "David L" wrote...
>> There is no real reason that FBO's can not get un-tainted
>> gasoline. The alcohols are added in when the truck is filled.
>> The difficulties are procedural not strategic...
>
> Yes and no. Most trucks have residual when they return to the farm to
> refill. Since most FBOs can't take the entire trailer, they will pay a
> premium to the trucking firm for a dedicated partial load. That markup is
> more than a few cents (more like 10 to 50 cents) per gallon, and then you'll
> still get a small mix of residual.
>
> The FBO is also not taking a trailer (or seven) a week, so every run is a
> special. That means the trucking co will fit the FBO in with no guarantees.
> So the FBO will need to schedule early (so as not to run out) and therefore
> will take even a smaller load. Sometimes the load is so small the FBO will
> have to take a mini, making the FBO pay for gas not taken.
>
> Also, many of the Quicky Marts make more profits from the food and coffee,
> than from the gas pumped. The FBO will not sell at such small margins, so
> all said and done the Mogas will likely be a dollar to 1.50 higher than the
> Quicky Mart. Now add in what Kyle B mentioned about the Mogas cutting into
> the FBOs Avgas sales and it's a loser all around (for the FBO).
>
> Damn those pesky details!
>
>
I really don't think that things are as gloomy as you put it.
i suspect that the fuel trucks are pretty capable of emptying their
trucks at their retailers. When 3000 gallons of fuel is ordered, I
suspect that 3000 gallons are put on the truck and delivered to it's
destination and the truck is emptied. Even if there were a few gallons
remaining, that amount of alcohol in 1000+ gallons of fuel is in the noise.
From the FBO's point of view, if there is a market for mogas, they will
be able to provide a service for it. If multiple FBO's sell mogas, then
competition will make the prices reasonable.
There are always those FBO's that really mark up their prices because
they have a captive crowd and those who would rather sell more fuel for
less of a price but make more money/profit in the end.
From the looks of it, there are more places in the country that provide
un-tainted fuel than sell tainted so the alcohol transport issue would
be a mute point for them.
I wouldn't be surprised if the major manufacturers of engines provided
approval for using mogas in their engines, some FBO's would switch to a
mogas only operation if the sales are there and they can't/won't provide
services for both types of fuels.

At this point this is all speculation on both sides of the fence, but I
can only see the good in offering alternative fuels for our aircraft at
a fair price.

I for one would fly more if the fuel were more reasonably priced and
help support the FBOs which offer affordable fuel.

Dave

How about the requirements for truck delivery of 100LL? I once
understand that there can be no other fuel on board the truck, and
that the tank(s) have to be flushed with 100 LL and the flushing
mixture thrown away (a hazardous waste?) before the airport load is
put in.

JGalban via AviationKB.com wrote:

>
> I'm curious where you got the 88 aviation octane number. If that is
> accurate, O-360s and IO-360s will likely be blowing holes in the tops of
> their pistons on hot days.
>
> John Galban=====>N4BQ (PA28-180)


Temp has almost nothing practical to do with the octane required. What
matters is the internal cylinder pressure. For example the IO-520 in my
Bo develops about 800 psi, sea level and standard day, at max rpm and
full throttle. The GAMI guys have instrumented aviation engines and
gathered this data. Neither Lyc or Continental have done so. At 800
psi the 520 is on the ragged edge of detonation. That's at 31 inches of
MP, what you'd get at sea level. They also determined that at 26 inches
of MP the 520 develops 400 psi. This is also why owners with constant
speed props are told to always reduce manifold pressure first. If you
are at 800 psi with everything wide open and you reduce rpm you have
made the situation worse. The engine stays at the high pressures
longer, and at a different spot relative to top dead center, because
you just made the engine turn slower. All bad. So the fact is that it
is the internal cylinder pressure that determines what octane you need.
While reading the article he wrote I got to thinking that I never see
over 26 inches of MP at my elevation of 3650 and of course the higher
you go the lower it gets. Therefore here at 3650 MSL 100 octane is not
needed, 90 would be more than adequate. And go to those mountain strips
that are higher yet and your octane requirement drops even lower.

JGalban via AviationKB.com wrote:
> Newps wrote:
>> Temp has almost nothing practical to do with the octane required. What
>> matters is the internal cylinder pressure.
>
> I agree that cylinder pressure is the primary factor, but intake
> temperatures can push detonation margins lower. That's why intercoolers and
> water injection systems were invented.

Yes, but raise the temperature of the air and you lower its density
altitude which reduces the octane requirement. So temp plays a factor
but it's a complex relationship.