110 Octane Sunoco ?

[Don Johnston]

I am using 89 E free fuel with stabilizer and no boosters.  6S2187 is tuned for it and runs very nicely.  See page 612 of the new 1966 Shelby Registry.  No complaints.

[rkm]

How much toluene should you mix with 10 gallons of 91 no ethanol pump gas to get, say, 100 octane?

[shelbydoug]

The question to me is simply why use 110 if you don't need it?

Octane rating, the higher you go, is simply the resistence to "dieseling" of the fuel. Dieseling being defined as combustion without an ignition spark and ignition by compressing the fuel.

High octane fuel does not produce more power.  In fact, lower octane fuel produces more heat calories per unit, making more power.

In addition, higher octane is usually obtained by adding compounds such as lead. That will add a white crusty deposit to both the spark plug electrodes AND the valves and valve seats.

It also creates an acid compound that initiates an internal process of rotting the exhaust system that otherwise would not occur.



ONE of the strange occurrences that you will notice in running racing gas is that the engine will IMMEDIATELY idle lower. For instance, if you were set to idle at say 950 rpm with pump gas, the engine will immediately drop down to like 550 or 600 rpm.

Why? The higher octane fuel produces less heat calories, i.e., less energy and the idle is showing the percentage of loss of power at idle.



At one time, when leaded gas was the fuel you got at any retail fuel supplier, one could walk along any street in a city and touch the dust laying along the curbside with your finger. That dust was nearly 100% lead that had settled from the exhausts of motor vehicles.

Of course I will also point out that when I started school and we were learning to write, the pencils that we were given were lead pencils. Yea, the bad stuff, so no one is innocent here, except maybe 5 year olds that were learning to write with poison sticks finished in lead based paints?

The teacher told us not to lick the tip, even though that made the pencil easier to write with and if we were good and if our hands started to itch we could go to the sink and wash our hands until the itching stopped.

i'm not accusing anyone of anything. Just explaining what I know within the limitations of my obviously lead damaged brain and nervous system?



UNLESS you ARE running 12.0:1 (sometimes as low as 11.0:1 to be fair) you positively do not want even 103 leaded gas in your  cars system. If you think you do then unfortunately you have not correctly analyzed the engineering here.

If you like the smell of it, just get a gallon and take the cap of the container and sniff it. Tires burn well too once you get them going. If you live in an apartment, put one in your barbecue and light it up.



It all depends on your background. To me, these smells just invoke memories of burning cities on fire from being under military seige. That is of course without the smell of the dead corpses of people and animals lying in the streets. That one's a real treat that you shouldn't miss? However there still are those that genuinely love the smell of napom in the morning. I don't, but that's just me?

I do admit that as a kid I did love the smell of the fumes of the gas as it was being pumped into Dad's gas tank and loved the woosey feeling it created. It was a cheap high?



I had a case of Moroso octane booster. Four one gallon cans. I was amused by the red skull and crossbones printed on the cans and the warning, "wear gloves in handling this compound. Do not get it on your skin. It will be absorbed through the skin and will block red blood cells from absorbing oxygen from the lungs". 

It went on to state, "in case of contact, get medical attention immediately", and described the effected area as turning purple from asphyxiation of the body tissue in that area. I don't know if that meant that you just killed your hand that turned purple, but maybe?

I gave it away to one of the local racers with a 65 GTO. I told him he had to get his own gloves. 

[rhjanes]

For folks in the Texas area, check out your local Buc-EE's.  They have 91 octane ethanol free fuel.  I just filled both old Mustangs with it and added some Sta-Bil.  It's priced the same as their 93 octane (which has ethanol). 

[427heaven]

How much toluene should you mix with 10 gallons of 91 no ethanol pump gas to get, say, 100 octane?

In reading Dougs response is pretty accurate, I didn't want to write a thesis on the subject. A quick overview of what you need would be the shade tree mechanics way of testing. To understand THERMODYNAMICS and how it relates to engines is a simple listening to when your engine starts to rattle or ping. For starters you need to start off with the highest octane gas you can start with for obvious reasons, then you will need to adjust your timing to advance or retard  the timing as a basis for testing. If you don't hear anything you don't need to continue and waste your money on additives. If you do, add about 1 ounce per gallon of gas this will fix most street engines pinging problems. Add or subtract as needed to find the sweet spot.

[The Going Thing]

Some of the aforementioned rules apply until you start with power adders. The custom grind cam I have was designed to assist with this issue. However, even with the new engine and my reduction to about 9.9:1 I still have an issue without running a minimum of 93. The new aluminum head design seems to be a bit more helpful with flame propagation and also allows me to drop the advance back from 38 to 36. I did note the fact that the economy is reduced with retarded timing settings. Any forced induction nullifies much of the previous argument.

[shelbydoug]

Some of the aforementioned rules apply until you start with power adders. The custom grind cam I have was designed to assist with this issue. However, even with the new engine and my reduction to about 9.9:1 I still have an issue without running a minimum of 93. The new aluminum head design seems to be a bit more helpful with flame propagation and also allows me to drop the advance back from 38 to 36. I did note the fact that the economy is reduced with retarded timing settings. Any forced induction nullifies much of the previous argument.

The aluminum heads seem to work as well or better at 32-33 degrees total. It kind of makes sense to me since the Pro-Stock BB GM's were backing off on timing through the traps to increase top speed.

Aluminum heads only loose more power through the aluminum due to thermodynamics.

The old "rule of thumb" was that you needed to increase static compression ratio 1.1:1 with an aluminum head to make equivalent power of an iron head.

That has almost nothing to do with the octane necessary to resist detonation since that is the effect of cylinder pressure, not thermodynamics.



I was not impressed, helped by or convinced that leaving the exhaust open longer will bleed off cylinder pressure in amounts significant enough to run 93 unleaded in an 11.5:1 engine. Been there. Done that. Didn't work for me.


What Keith is correct to point out here is that the flame travel caused by the shape of the combustion chambers does effect cylinder pressures.

In the case of Fords, seemingly you can run a 10.5:1 289 on 89 regular all day and at the track, whereas the Cleveland and the FE are just "mutha's" on demanding high octane fuels even at that 10.5:1.


So the answer is, every time you mess with these engines in changing something,  even as simple as a cam duration and overlap, you might change the need for fuel octane?

Adding a lead compound to the fuel is the simplest way to increase octane.



During the two fuel shortages of the '70s, the fuel manufacturers "bitched" that in order to make even 103, it had to come off of "the top of the barrel".  I'm sure that's a "refiners term" used to scare the crap out of politicians?

The laymans explanation I got from Exon (I did work for the CEO at the time, he was an engineer, not an MBA...amazing right?) was that for every gallon of high octane gas he could make 10 gallons of regular.

At this point he got nasty and said WTF are you to be so demanding? At this point I took the men off the job and let his skylight holes leak water all winter until he asked me to come back in May...nicely?

I think he got letters telling him to FO. I have no idea how his personal address got out to the public? What a shame? 

[The Going Thing]

I agree with you, Doug. The standard FE chambers leave much to be desired. It's compounded when the quench isn't right. On the convertible with the turbocharged six there is actually a sticker in the gas door that the minimum is 91 octane.  The new lincoln, on the other hand, seems completely happy with regular.

[kjspeed]

Not an FE, but my 13:1 351C likes Sunoco 110. A lot! John Barnes told me when I bought the car that it didn't "need" 110 but he liked the smell. Me too! Better than most perfumes but I can't get my wife to splash some on her neck. 


But being a stingy Irishman, I have found that cutting the 110 with 25% 89 non-ethanol (which supposedly tests out at 90-91 but they don't want to re-label the pump) works just about as good, smells good and costs a little less per mile. By the way, I'm paying less than $9/gallon for the 110 fuel, so it's relatively inexpensive here. If I went to the race track - $12-$15 per gallon.

[shelbydoug]

Not an FE, but my 13:1 351C likes Sunoco 110. A lot! John Barnes told me when I bought the car that it didn't "need" 110 but he liked the smell. Me too! Better than most perfumes but I can't get my wife to splash some on her neck. 


But being a stingy Irishman, I have found that cutting the 110 with 25% 89 non-ethanol (which supposedly tests out at 90-91 but they don't want to re-label the pump) works just about as good, smells good and costs a little less per mile. By the way, I'm paying less than $9/gallon for the 110 fuel, so it's relatively inexpensive here. If I went to the race track - $12-$15 per gallon.

I had 11.8:1 TRW pop up pistons in the iron closed chamber heads. On pump gas the detonation got so bad that the engine would just shut itself off if you suddenly wot it.

Then I tried the open chamber heads and the engine became a slug which signed it's own death warrant.

Pump gas in Europe is about $9 a gallon. They pay per liter what we pay per gallon. I'm not sure if 110 is anywhere but at a race track in Europe. It's not at the pumps because of the lead.

[The Going Thing]

When I was in Madrid Spain in October the octane rating for regular was 92, the premium was 95 and Super was 97. It was damn expensive too.
It was about 7.50 U.S. per gallon. Spain and France were much less expensive than in London.  The taxes on fuel in the U.K. are horrid.

[shelbydoug]

When I was in Madrid Spain in October the octane rating for regular was 92, the premium was 95 and Super was 97. It was damn expensive too.
It was about 7.50 U.S. per gallon. Spain and France were much less expensive than in London.  The taxes on fuel in the U.K. are horrid.

What octane rating system were they using? Their 97 is our 93?

I remember Sunoco 260 was 103 under the old system. That stuff was purple and had that nighty-night smell to it. I'd get really light headed pumping it. That's when I liked full service stations except they'd always have a problem with the fuel filler and scratch up the Shelby decal on it.

Most would try to twist the thing off. I guess a quick fill pop open was too abstract of an idea?

[98SVT - was 06GT]

When I was in Madrid Spain in October the octane rating for regular was 92, the premium was 95 and Super was 97. It was damn expensive too.
It was about 7.50 U.S. per gallon. Spain and France were much less expensive than in London.  The taxes on fuel in the U.K. are horrid.

You were getting screwed even further. Europe uses the research method for octane rating which produces a higher number than the motor rating method. Here in the US they use both methods and average the results to post on the pump. Europe also ran baby motors with high compression so the octane needed to be higher. The downside was it produced more CO.

[oldcanuck]

So ideally for my stock 10.5 / 1 SB..... adding some type of lead additive is best for 93 pump gas rather than an octane booster ?  Anybody recommend a good product ? 

As always, thanks in advance.

[CSX 4133]

Bob,

Redlines lead additive has been used amongst the '20's thru '50's car crowd for years, one bottle treats 20 gallons of fuel. Shop around I think one can find it cheaper than Redlines link below. Your car should run fine on 93 octane, especially the kind without the corn additive. 

https://www.redlineoil.com/lead-substitute