Vintage Mustang Forums banner
1 - 20 of 40 Posts

·
Registered
Joined
·
1,199 Posts
Discussion Starter · #1 ·
So I drove my 68' from Northern Virginia near the Pentagon and D.C. all the way down to South Carolina a couple of days ago over 400 miles. Didn't miss a beat and at one point even hit 20 mpg on one tank (typically 18). Last fill as empty as I'd dare take it was about 14 gallons of Ethanol Free 90 while it sits for the next 2-3 months getting repainted over winter.

I noticed the two times I have switched to a tank of the stuff is that the first time I give the accelerator a good stomp it chokes up real hard but then reels it back without stalling....never to do it again! This happened in North Carolina close to the SC destination....and in rural Virginia last year when I found an ethanol free pump about 60 miles from home. Again I usually do this when the car is about to sit idle for a long period. Stuff is quite hard to find in Northern VA and Maryland. Bit easier in the Carolinas.

Does anyone know why this happens? Just curious. It's a 302 with a 600 CFM 4 bbl Holley 4160 and all including the motor and tranny are low mileage rebuilt in the past 3 years. I've put a camera scope on a wire down the tank and there is not any major flotsam or corrosion down there. I change the inline fuel filter once per year.
 

Attachments

·
Registered
1966 Mustang GT Coupe Auto
Joined
·
61 Posts
If you were going up hills at the time it sounds like percolation from a hot fuel line. Half or quarter throttle would keep the car going. That's a big reason for electric fuel pumps to overcome the hot fuel.

If not, never mind!
 

·
Registered
Joined
·
1,616 Posts
You're running leaner with the ethanol gas. A 600 is as large a carb as you would want to run on a stock 302. Maybe your carb is providing a slightly rich condition when you run the non-ethanol gas if your car is tuned ethanol.
 

·
Registered
Joined
·
6,294 Posts
You're running leaner with the ethanol gas. A 600 is as large a carb as you would want to run on a stock 302. Maybe your carb is providing a slightly rich condition when you run the non-ethanol gas if your car is tuned ethanol.
Maybe I’m misunderstanding you, and if I am, my apologies but the CFM rating of a carb doesn’t make it rich or lean.
 

·
Registered
Joined
·
1,199 Posts
Discussion Starter · #6 ·
Js, why are you choosing fuel without ethanol ? We've had gas here for decades with ethanol . No troubles. LSG
Its definitely a better option when there car is sitting for a prolonged period. I’ve seen videos where a guy meticulously examined differences in the corrosive effects of 10% 85% Ethanol and ethanol free on metals and how score it is to deliver startup after 9 months. Plus how well the protection additives help with that. Usually I’m going through a tank quickly enough even in winter. But it’ll sit for 3-4 months at this guys body shop. He will occasionally start it up though and let it reach full temp.

Other than that I’ve had no trouble with Ethanol.
 

·
Registered
1969 Mustang Coupe
Joined
·
246 Posts
I do not believe it is necessary to run larger engines on ethanol free gas pre-storage. The fuel we get in general now is garbage for the most part and no matter what, only has about a 3 month shelf life before it breaks down and begins to congile. Small engines are a different story and ethanol can and will degrade fuel lines and the likes. Until I figured this out, I lost countless hours of my life every spring rebuilding the fuel systems on weed whackers, snow blowers, motorcycles etc. but never had issues with larger engines "due to" ethanol. Crappy fuel is yet another story and the congealed mess left behind from the garbage we are sold as gas in Canada and the US is the stuff nightmares are made of. I've tried fuel stabilizers, alcohol additives to combat water and different grades of fuel up to 94 octane ethanol free and there is little difference after a few months. The best, IMO, is the most expensive option and that is imported fuel sold in small jugs from Aspen. The straight fuel option has a 3-4 year shelf life and the pre-mix stuff for 2 stroke engines is good for up to 5 years. I've used this stuff in my motors for many years and swear by it up here in the great white north (PNW). We have a special kind of issue here with copious amounts of moisture in the air which coupled with huge daily changes in temperature can cause a gas tank to expand and contract like an accordion, that over time can add inches of water to a tank of gas. I had ruined several metal tanks on motorcycles and generators before I learned what to and not to use. Best thing for storing a large vehicle is to drain it completely and empty the lines and carbs of any fuel whatsoever. Then pour a little Methyl hydrate (gas line antifreeze) into the tank to keep out any water. Secondly you can run the motor dry, ensuring the carb (or whatever) is dry, then fill the tank completely to the top with fuel (with the least amount of additives), add some Methyl hydrate and a bit of fuel stabilizer and hope for the best for no more than 6 months.
 

·
Registered
Joined
·
1,199 Posts
Discussion Starter · #8 ·
If you were going up hills at the time it sounds like percolation from a hot fuel line. Half or quarter throttle would keep the car going. That's a big reason for electric fuel pumps to overcome the hot fuel.

If not, never mind!
In both cases it was dead flat
If you were going up hills at the time it sounds like percolation from a hot fuel line. Half or quarter throttle would keep the car going. That's a big reason for electric fuel pumps to overcome the hot fuel.

If not, never mind!
In both cases dead flat and coolish outside. Does it just once and that’s it. I also have a carb spacer and in never had percolation or vapor link issues even in the hottest days or going up mountains.
 

·
Registered
Joined
·
1,199 Posts
Discussion Starter · #9 ·
I do not believe it is necessary to run larger engines on ethanol free gas pre-storage. The fuel we get in general now is garbage for the most part and no matter what, only has about a 3 month shelf life before it breaks down and begins to congile. Small engines are a different story and ethanol can and will degrade fuel lines and the likes. Until I figured this out, I lost countless hours of my life every spring rebuilding the fuel systems on weed whackers, snow blowers, motorcycles etc. but never had issues with larger engines "due to" ethanol. Crappy fuel is yet another story and the congealed mess left behind from the garbage we are sold as gas in Canada and the US is the stuff nightmares are made of. I've tried fuel stabilizers, alcohol additives to combat water and different grades of fuel up to 94 octane ethanol free and there is little difference after a few months. The best, IMO, is the most expensive option and that is imported fuel sold in small jugs from Aspen. The straight fuel option has a 3-4 year shelf life and the pre-mix stuff for 2 stroke engines is good for up to 5 years. I've used this stuff in my motors for many years and swear by it up here in the great white north (PNW). We have a special kind of issue here with copious amounts of moisture in the air which coupled with huge daily changes in temperature can cause a gas tank to expand and contract like an accordion, that over time can add inches of water to a tank of gas. I had ruined several metal tanks on motorcycles and generators before I learned what to and not to use. Best thing for storing a large vehicle is to drain it completely and empty the lines and carbs of any fuel whatsoever. Then pour a little Methyl hydrate (gas line antifreeze) into the tank to keep out any water. Secondly you can run the motor dry, ensuring the carb (or whatever) is dry, then fill the tank completely to the top with fuel (with the least amount of additives), add some Methyl hydrate and a bit of fuel stabilizer and hope for the best for no more than 6 months.
I’m from the PNW - Seattle originally so I get what you are saying. Thanks for your input. In VA/MD we have lots of humidity and wide swings in temp and humidity esp during winter. Luckily this car will be in South Carolina where it’s going to be quite a bit warmer all through the winter. I agree long term storage is best to drain the tank and run carb dry. I’ve heard though that this can cause seals in the carb prev immersed in gas to dry out and crack. Guy has to move the car around so non ethanol was the lesser of all evils.
 

·
Registered
Joined
·
1,199 Posts
Discussion Starter · #10 · (Edited)
You're running leaner with the ethanol gas. A 600 is as large a carb as you would want to run on a stock 302. Maybe your carb is providing a slightly rich condition when you run the non-ethanol gas if your car is tuned ethanol.
Sounds like the most plausible answer. But it only does it once while in transition when the ‘new’ gas hits. Thankfully enough!
My 600 Holley does indeed like to idle a bit rich but it has a nice lean cruise. How do I know this? Got tired of reading plugs for each tune and I’ll put an AFR gauge on it only while tuning. 14.50-75 is considered most optimal. It starts up in the 12.00 range. Once warmed up I set it at the high 13 or low 14 range. If I set it to 14.50-75 car will start horribly lean and run terribly for a while.
Cruise had nothing to do with the idle circuit so I’m probably not too under or over jetted with a sold 14.50 to 15 cruise. I am however a bit lean on hard accel and this is because the vacuum secondaries are a metering plate in the 4160. I could swap that too a secondary with jets.

If I keep this engine longer than a year or two I’m considering going to a 500cfm Edelbrock they I can re-jet going up steep mountains on trips. Also the flow and velocity is said to be a bit more optimum for a 302 at 500cfm.

Now I might go 331 stroker and that would be a totally different setup 😉🤣
 

Attachments

·
Registered
Joined
·
1,889 Posts
Maybe on that first stomp you are getting, and clearing out, the old E-gas that is still in the accelerator pump, then after that the accelerator pump is happier with the non-E gas?

I wish we could buy non-ethanol (and put it in our cars) here in Calif.
I can buy it at a station about 30 minutes away, but the pump is locked, it must be pumped by an employee, it can't be pumped into a vehicle so it must be put in containers.
It is "not of use in motor vehicles" according to the label on the pump. Oh, and the containers that everyone on the planet uses for their fuel, are made in Sacramento Calif.(state capital) but Summitt can not ship them to a Calif. address?!?!

When we took the road trip in our '65 GTFB in June 2019 from Nor-Cal to Minnesota and back I enjoyed being able to get non-E gas (ironically in all the states the corn it's made from is grown, like my wife's home state of Iowa). I noticed better mileage with the non-E and non-Calif gas, 23mpg on the best leg with the original un-rebuilt A code 289, 4 speed and 3.00 gears.
 

·
Registered
66 fastback
Joined
·
269 Posts
So I drove my 68' from Northern Virginia near the Pentagon and D.C. all the way down to South Carolina a couple of days ago over 400 miles. Didn't miss a beat and at one point even hit 20 mpg on one tank (typically 18). Last fill as empty as I'd dare take it was about 14 gallons of Ethanol Free 90 while it sits for the next 2-3 months getting repainted over winter.

I noticed the two times I have switched to a tank of the stuff is that the first time I give the accelerator a good stomp it chokes up real hard but then reels it back without stalling....never to do it again! This happened in North Carolina close to the SC destination....and in rural Virginia last year when I found an ethanol free pump about 60 miles from home. Again I usually do this when the car is about to sit idle for a long period. Stuff is quite hard to find in Northern VA and Maryland. Bit easier in the Carolinas.

Does anyone know why this happens? Just curious. It's a 302 with a 600 CFM 4 bbl Holley 4160 and all including the motor and tranny are low mileage rebuilt in the past 3 years. I've put a camera scope on a wire down the tank and there is not any major flotsam or corrosion down there. I change the inline fuel filter once per year.
It's your carb spitting out the last of that nasty corn juice fuel....
 

·
Registered
Joined
·
1,199 Posts
Discussion Starter · #14 ·
Maybe on that first stomp you are getting, and clearing out, the old E-gas that is still in the accelerator pump, then after that the accelerator pump is happier with the non-E gas?

I wish we could buy non-ethanol (and put it in our cars) here in Calif.
I can buy it at a station about 30 minutes away, but the pump is locked, it must be pumped by an employee, it can't be pumped into a vehicle so it must be put in containers.
It is "not of use in motor vehicles" according to the label on the pump. Oh, and the containers that everyone on the planet uses for their fuel, are made in Sacramento Calif.(state capital) but Summitt can not ship them to a Calif. address?!?!

When we took the road trip in our '65 GTFB in June 2019 from Nor-Cal to Minnesota and back I enjoyed being able to get non-E gas (ironically in all the states the corn it's made from is grown, like my wife's home state of Iowa). I noticed better mileage with the non-E and non-Calif gas, 23mpg on the best leg with the original un-rebuilt A code 289, 4 speed and 3.00 gears.


I can get it in rural Virginia or one nearby city that is a bit south Fredericksburg VA. But going 50 miles for gas for anything other than filling a drum or for winter storage isn’t practical. But the DC Area is on the same restrictions and tailpipe standards as.

Don’t think it’s a matter of being ‘happy’ or not. It’s just as happy on 10% ethanol. It’s the transition. Someone says it’s leaned but then it’s changing to a richer jetting. I can believe that. But then would it not repeat the trend? This has actually played out 3 separate times now that I think about it. This car also runs a bit better on Shell gas for some reason.
 

·
Registered
Joined
·
5,293 Posts
I tried E-free gas once in my 65, ran like crap.
 
  • Like
Reactions: Tomn

·
Premium Member
Joined
·
8,248 Posts
I definitely get better fuel mileage, and easier starts in hot weather with non-ethanol fuel. My wife's SUV gets a little better mileage with it too, even though it is designed as a flexible fuel vehicle.
 

·
Registered
Joined
·
265 Posts
I run 91 non oxygenated fuel (ethanol free) in both my 90 coupe and 67 fastback. Why not? It's also higher octane than the 88 we have with 10% ethanol.

And I'm a fan of ethanol in general. I run E70-E85 in my 03 cobra 99% of the time. The only time it sees 91 octane is during winter storage.




Sent from my Moto E (4) Plus using Tapatalk
 

·
Registered
Joined
·
811 Posts
I definitely get better fuel mileage, and easier starts in hot weather with non-ethanol fuel. My wife's SUV gets a little better mileage with it too, even though it is designed as a flexible fuel vehicle.
it should get better gas mileage, you need to burn more E-gas per mile than "E-free" gas. I believe a car running E85 needs about 30-40% more fuel compared to "E-free"
 

·
Registered
Joined
·
5,293 Posts
Gas mileage.........Really?

The money nearly everyone on this board pours into these cars and you are going to talk about gas mileage.
 
1 - 20 of 40 Posts
Top