Ethanol vs non Ethanol gas octane issues

[Chevelle3221]

My 1970 Chevelle SS 396/350 HP stock motor requires premium fuel. My problem is that I can only get 90 non ethanol gas locally and my car wants higher. I can get 93 ethanol gas but I do not think its better for my carb (newer unit). Currently I am using the 93 ethanol but also adding Starbrite Star-Tron stabilizer to counter the ill effects of the ethanol. My concern is fouling the plugs with all this crap. Opinions

I do not store the car for months on end but obviously don't drive it everyday.

 

[RDY4WAR]

I would use the 93 with 10% ethanol and not think twice about it. So long as you start it once every couple weeks and go through the tank within 4-5 months, you won't have any issues.

The ethanol problems are often blown massively out of proportion. Most of the people that have problems let their stuff sit for months in sub-freezing temperatures with a poorly sealed fuel system. Anything left to sit for months is going to give you fits, ethanol or not.

I ran E10 93 in my '66 Mustang (289ci with 750 carb) for years and never had a single problem from it. Even sitting for 2-3 months, I could get in, just one pump of the pedal, and it would fire right up and idle smooth.

 

[ctechbob]

I'd be more worried with fuel system issues as opposed to fouling plugs. I'm assuming that car sits a lot of the time, that's where your problems would be. If you're going through a tank of gas a month you'll be fine.

 

[#18FAN]

Go all out perfect solution.
https://vpracingfuels.com/product/c9/?c=220&

 

[Chevelle3221]

Go all out perfect solution.
https://vpracingfuels.com/product/c9/?c=220&

LOL

 

[atikovi]

Why not just convert it to run on E85 which is over 100 octane from the get go?

 

[brianl703]

The ethanol problems are often blown massively out of proportion. Most of the people that have problems let their stuff sit for months in sub-freezing temperatures with a poorly sealed fuel system. Anything left to sit for months is going to give you fits, ethanol or not.

I use E10 in my riding mower which sits in my garage all winter. I do not drain the fuel out of it or run it empty at the end of the season.

It always fires right up in the spring.

 

[#18FAN]

LOL

No really it is the solution.

 

[Chevelle3221]

Why not just convert it to run on E85 which is over 100 octane from the get go?

Not an option

 

[RDY4WAR]

No really it is the solution.

At $17.80 gallon (without shipping) and lucky if you can get it, that's not really a solution. None of my local VP dealers have any and can't get any. It was tough to come by even before the pandemic. It's one of the reasons I switched from that to E85.

 

[#18FAN]

At $17.80 gallon (without shipping) and lucky if you can get it, that's not really a solution. None of my local VP dealers have any and can't get any. It's one of the reasons I switched from that to E85.

My dealer has skid of it at 12.50 a gallon

 

[ChrisMU]

Non-ethanol gas plus octane booster?

 

[oldhp]

Add 4ozs of MMO to every 10gal 93 octane. Keeps inside of carb clean, no white scum from the ethanol.

 

[eljefino]

Toluene has an octane of 114, so maybe throw a couple gallons of that in every tank? That, or LL100 avgas.

My carbureted plow truck sits all summer on E10 with pink sta-bil and fires up in the fall. Takes 30 seconds of cranking as the carb "dries out" but it's probably better that way.

 

[RDY4WAR]

Toluene has an octane of 114, so maybe throw a couple gallons of that in every tank? That, or LL100 avgas.

My carbureted plow truck sits all summer on E10 with pink sta-bil and fires up in the fall. Takes 30 seconds of cranking as the carb "dries out" but it's probably better that way.

It's a poor choice here since he's NA. Toluene will make the fuel more difficult to vaporize and slow the burn rate. Great for a boosted engine though.

Avgas is in the same boat as it contains a bunch of stuff that burns poorly at ground level. It contains a lot of heavy aromatics to prevent evaporation a high altitude and isopropyl alcohol as anti-freeze. It also has a stoich closer to 13.5 which many people don't account for.

 

[Accent Abuser]

Non-ethanol gas plus octane booster?

Something with MMT would work, I've used the orange STP bottles and Royal purple max boost a few times with regular 87 and it didn't knock one bit. I also agree the ethanol concerns are overblown.

 

[Skippy722]

Non-ethanol gas plus octane booster?

The demon and Hellcat guys like Boostane.

 

[Cujet]

Avgas is in the same boat as it contains a bunch of stuff that burns poorly at ground level. It contains a lot of heavy aromatics to prevent evaporation a high altitude and isopropyl alcohol as anti-freeze. It also has a stoich closer to 13.5 which many people don't account for.

100LL may not be an ideal choice for many reasons. Not the least of which is the high lead content that will contaminate the oil, leave deposits and foul plugs.

However, it's Stoicheometric ratio is very close to 15 to 1 and will operate cleanly in many engines from 11 to 1 all the way to 17 to 1. It contains no alcohol of any sort, and evaporates more readily than auto fuels. It is designed to evaporate at high altitudes and very cold temperatures.

I think you are referencing it's Reid Vapor Pressure, 100LL's RVP is greater than 38.

Anyone who has thrown a sumped sample of 100LL on the ramp knows it evaporates very rapidly and completely. Unlike auto fuels which tend to leave a puddle. Avgas is mostly Alkylate with under 7% toluene. Avgas will run very well in his engine at any altitude. It's just not a good choice due to contamination.

 

[wings&wheels]

100LL may not be an ideal choice for many reasons. Not the least of which is the high lead content that will contaminate the oil, leave deposits and foul plugs.

However, it's Stoicheometric ratio is very close to 15 to 1 and will operate cleanly in many engines from 11 to 1 all the way to 17 to 1. It contains no alcohol of any sort, and evaporates more readily than auto fuels. It is designed to evaporate at high altitudes and very cold temperatures.

I think you are referencing it's Reid Vapor Pressure, 100LL's RVP is greater than 38.

Anyone who has thrown a sumped sample of 100LL on the ramp knows it evaporates very rapidly and completely. Unlike auto fuels which tend to leave a puddle. Avgas is mostly Alkylate with under 7% toluene. Avgas will run very well in his engine at any altitude. It's just not a good choice due to contamination.

...and its potential incompatibility with synthetic oils' inability to suspend lead deposits if you use them. Historically at least.

Thats said 100LL starts fine and runs quite nicely in vintage car and boat engines, and its stability is ideal for storage.

Back on topic, since you are using the car regularly, not letting it sit for extended periods of time, you should not have a problem. I have had issues with carb deposits, but my toys sit for ~5 mos at a time. I have had less problems since I started using Marine Sta-Bil religiously.

 

[SHOZ]

Been using E10 in everything since the late 1970's Two cycles and crappy B&S carb motors are the only things that I have issues with.