Ethanol gas question

[Ratty_81]

I always throw some Stabil in my old car tanks. I also top off with E0 before winter. A tank of fuel might last 3-4 months in my 94 Silverado.

 

[larrylarry]

@larrylarry. I responded in your other post about your "pinging" issue. I think the "hate on" for ethanol comes from perhaps not driving ones hot rod enough or on a regular basis, having it sitting for long periods, or even worse in damp garage or location or a combination of all of these.

Ethanol is hydroscopic, it attracts moisture, and that can ruin carbs and fuel systems real quick, like small engines that sit lots in the shed, and only get used a few seasons out of the year.

The other important points that Bikefixr has clearly pointed out, most "carbs" are calibrated for pure gasoline and considering the energy or lack of BTU's in the Ethanol, even at 10%, the carb need to be calibrated/tuned accordingly.

The Ethanol's fresh charge cooling effect can be used to actually suppresses detonation, not encourage it, especially in a carb application.

There's actually some key advantages to using pump fuel with Ethanol, you need to tune for it, and actually measure what the % is, but if you have a higher CR engine, and it's asking for more octane, many times the Ethanol can be made to work for you, not against you.

 

[larrylarry]

Almost every gas station around here is Valero & a few Shell,Exxon,Chevron & Walmart. You can find E85 but not all stations sell it. I’ve never seen any non ethanol gas sold here and trying to find a octane higher than 93 is non existent. I do know of a VP distributor here but that’s a bit too much to pay for.

 

[G72Zed]

I think if you can find some 91 or 93 octane with 10% Ethanol you could try that out. do you use a PCV at all ? what plugs exactly, also what carb are you running ?

 

[FS87LT]

Not sure about San Antone, but in the DFW area, LOTs of stations sell ethanol-free gas. Usually Murphy Oil/Walmart stations. QTs have E85 and in some areas up here, E15 rather than diesel. LOTS of yard services up here which are customers of the E0 fuel.

Ethanol is an octane booster, so it should NOT cause any pinging from my experiences. Provided you don't have the timing jacked-up too much.

93 Pump Octane fuel is usually at least 97 Research Octane, maybe a number or two higher. Two DIFFERENT octane ratings! Used to be that a 10.0CR engine needed 97 Research Octane to be able to use enough spark advance for optimum power. 95.5 Pump Octane would be 101 Research Octane.

Notice in the E0 fuel listings that most of the E0 fuels available are basically 87 Pump Octane or lower. Unless the station also sells "niche market" E0 race gas.

Most of the E0 stations will be near marinas, typically. In which case, the price might not include "road taxes" as other gas stations would.

As things have evolved, E10 fuels have spread into areas where they were not really needed for air quality issues. Not all states have labeling requirements for the gas pumps either, so the pump can dispense E10 fuels without any notification of such.

There used to be a map in the back of the Exxon-Mobil website which illustrated which fuels HAD to be where, in the nation. By observation, lots of E10 gets to places it is not required to be.

FS87LT

 

[biker]

Not sure about San Antone, but in the DFW area, LOTs of stations sell ethanol-free gas. Usually Murphy Oil/Walmart stations. QTs have E85 and in some areas up here, E15 rather than diesel. LOTS of yard services up here which are customers of the E0 fuel.

Ethanol is an octane booster, so it should NOT cause any pinging from my experiences. Provided you don't have the timing jacked-up too much.

93 Pump Octane fuel is usually at least 97 Research Octane, maybe a number or two higher. Two DIFFERENT octane ratings! Used to be that a 10.0CR engine needed 97 Research Octane to be able to use enough spark advance for optimum power. 95.5 Pump Octane would be 101 Research Octane.

Notice in the E0 fuel listings that most of the E0 fuels available are basically 87 Pump Octane or lower. Unless the station also sells "niche market" E0 race gas.

Most of the E0 stations will be near marinas, typically. In which case, the price might not include "road taxes" as other gas stations would.

As things have evolved, E10 fuels have spread into areas where they were not really needed for air quality issues. Not all states have labeling requirements for the gas pumps either, so the pump can dispense E10 fuels without any notification of such.

There used to be a map in the back of the Exxon-Mobil website which illustrated which fuels HAD to be where, in the nation. By observation, lots of E10 gets to places it is not required to be.

FS87LT

Yes, it's a good octane booster, but as G72 pointed out, it needs slightly fatter jetting to maintain a safe air/fuel ratio. Any ethanol related pinging is indirect, caused by the increased heat of a lean mixture when jetted for pure gasoline. Not an issue if your carb (like most) are set up fat, but if on the ragged edge of jetting it might be an issue.

 

[Gary S]

Have you checked the link in post #7? If it is correct, there are over 20 stations listed there that sell pure gas in the San Antonio area.

 

[cadillac_al]

I have run ethanol gas in everything I drive for many many years. I don't see any problems with it. As for pinging I would adjust the ignition timing to eliminate it. I had a vehicle once that would ping on slight acceleration. Once I have it a little more gas, the vacuum would go down and the vacuum advance would back off some more and all was fine. I used to like researching vacuum advance controllers and finding just the right one for my engine requirements. There are hundreds of different ones. I never liked the adjustable ones personally. If I can find that vacuum controler chart I will try to add it here.

Here it is.

http://outintheshop.com/faq/Vac%20Adv%20Spec.pdf

 

[G72Zed]

Have you checked the link in post #7? If it is correct, there are over 20 stations listed there that sell pure gas in the San Antonio area.

And by the list it gives in that area, highest pump octane that's E free is 91. As mentioned, I would look at the ignition/carb tune/timing and to a more extent, P to H clearance's.

The P to H distance is one of those things that less is more....even though it raises CR.

 

[FS87LT]

Yes, it's a good octane booster, but as G72 pointed out, it needs slightly fatter jetting to maintain a safe air/fuel ratio. Any ethanol related pinging is indirect, caused by the increased heat of a lean mixture when jetted for pure gasoline. Not an issue if your carb (like most) are set up fat, but if on the ragged edge of jetting it might be an issue.

All of the carbs I've bought have been OEM-spec direct replacements from Holley. First a 4160 and then a 9895 L82 Corvette spreadbore w/elec choke. I made no changes in the jetting changes as E10 (and the RFG which came before it) came to our area. No issues with pinging or similar from the prior fuels. No changes to the initial timing, either. With the 9895, average mpg went up by 2-2.5mph, with 23.5mpg on a freeway loop I used to do, with the 525K 305, 2.56 G80, P225/70R-15 Radial TAs, the night before the 355 was installed. Holley 28-Z intake, 210 @ .050, .440 lift, stock exhaust manifolds, honeycomb replacement converter, and Z/28 cat-back. Good enough to make a new '87 Mustang GT owner mad on the Interstate one day (in a 70-110mph run), at 235K miles, but a nice road car, too.

Just my experiences, yours might vary.
FS87LT