Aviation Gasoline

[Larry M.]

Re: Aviation Gasoline

Adding 10% ethanol to gasoline will boost the pump octane number by approx 2. So 87 PON non ethano gasl + 10% ethanol = 89 PON fuel. Ethanol has an octane rating of around 113 (PON) according to most sources.

VP 110 has a MON of 107 and a RON of 113. So the PON is 110.

Not certain about 100 LL. But Duke has explained this before regarding what the approximate equivalent PON number is. I will try to find his number and post it. I think it is about 105 PON. EDIT: This is confirmed after searching my files.

Larry

[Larry M.]

Re: Aviation Gasoline

Joe:

Let me explain what I see with ethanol containing gas and atmospheric moisture here in the Deep South. If I put a 6 quart pail containing about 2 quarts of ethanol laced gas outside with very high humidity (90% range), the light components in the gas quickly evaporate and the gas in the pail gets very cold due to this evaporation. This condenses moisture from the atmosphere onto the cold surface of the gas. The gas becomes hazy/milky from this condensed moisture (water). After an hour or so, the gas in the pail is still cool and I often see a teaspoon or so of water in a separate phase at the bottom of the pail.

This does not happen (milky gas or phase separation) with my non-ethanol gas.

FWIW.

Larry

[John D.]

Re: Aviation Gasoline

100LL is my favorite. Indefinite shelve life. Have proof it's good for at least 40 years as a member of the Pittsburgh Tri-State Chapter put 40 year old 100LL in his 1964 Corvette fuel car.
Story: At Corvette Carlisle on Thursday it was over 90 degrees. My one year old Honda 2000i generator had 100LL in it. When it ran out of fuel in the afternoon my son quickly filled the generator up and it started immediately.
With good old ethanol the generator would NOT start. John

[Joe T.]

Re: Aviation Gasoline

Duke

I used the PON example to identify 3 non-ethanol lased fuels 90, 100 LL and VP 110. So, Joe Lucia answered my question. 93 PON has 10% ethanol. Kind of easy to understand.

Joe

[Joe T.]

Re: Aviation Gasoline

Larry

Thanks. Good information

Joe

[Joe T.]

Re: Aviation Gasoline

Wow!

A big thanks to all of you. I have certainly learned a lot about selecting the fuel for my 427.

Joe

[Larry M.]

Re: Aviation Gasoline

Joe:

I can buy 93 PON gas without ethanol at MANY gas stations here in the New Orleans area. Although it can be sourced from many refineries, the 93 PON non-ethanol gas I buy is made nearby at the Exxon-Mobil Refinery in Chalmette, Louisiana.

I can also buy 93 PON gas containing ethanol. Generally Shell V-Power. Also made nearby in Norco, Louisiana.

I use the non-ethanol gas to mix 50/50 with VP 110 for my 1967 Corvette. This should produce gas having around 102 PON (which equates to about 107 RON using the rating system from the old days). I use the ethanol containing gas in my 2011 Corvette Grand Sport and in my daily driver car.

Larry

[Duke W.]

Re: Aviation Gasoline

Adding 10% ethanol to gasoline will boost the pump octane number by approx 2. So 87 PON non ethano gasl + 10% ethanol = 89 PON fuel. Ethanol has an octane rating of around 113 (PON) according to most sources.

VP 110 has a MON of 107 and a RON of 113. So the PON is 110.

Not certain about 100 LL. But Duke has explained this before regarding what the approximate equivalent PON number is. I will try to find his number and post it. I think it is about 105 PON. EDIT: This is confirmed after searching my files.

Larry

PON =(RON +MON)/2

RON - MON is what's called "sensitivity" and is usually in the range of 8 - 10.

The "Aviation Method" that is used to derive the octane number of avgas yields numbers very close to MON, so the RON is about 108-110 and PON is 104-105.

I think the octane number you quoted for ethanol is RON, not PON

Duke

[Larry M.]

Re: Aviation Gasoline

PON =(RON +MON)/2

RON - MON is what's called "sensitivity" and is usually in the range of 8 - 10.

The "Aviation Method" that is used to derive the octane number of avgas yields numbers very close to MON, so the RON is about 108-110 and PON is 104-105.

I think the octane number you quoted for ethanol is RON, not PON

Duke

One source: https://www.sunocoracefuels.com/tech...hol-and-octane Appears it depends on who does the reporting and how much is added. Agree most technical journals show lower ethanol octane numbers than I used. SUNOCO article shows both "stand-alone octane number" and "blending octane number"

I assume most agree they are a reputable source of gasoline information.

Larry

[Daniel Y.]

Re: Aviation Gasoline

I never use ethanol. I have used AV gas to mix 50/50. but its easier to buy racing fuel 112 octane in 5 gal cans at A&A auto supplies. works great

[John D.]

Re: Aviation Gasoline

You know you have the real deal 100LL fuel when you smell the exhaust pipes. It smells sweat.
One time at an NCRS regional at Marlborough my 63 was going thru ops. John Bollard said to me. DeGregory WTH are you burning in that fuel car.
He said smells sweet.
This afternoon I put 5 gallons in it in my 1928 Ford Roadster Pickup with the 4 cylinder engine. Now I don't have to worry about the fuel going bad all winter. John

[Mike M.]

Re: Aviation Gasoline

john: if u want the 63 to really smell sweet, get a 4 oz bottle of Power Plus Cherry Bomb. really smells like marachino cherry. mike