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I am wondering what octane you guys are running in your cars. I am especially interested in what octane you are running if you have mainly stock engines. Also, do you guys use any fuel additives?

Thanks!
 

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Highest octane you can find at the pump...... In my neck of the woods, that's 91.
 

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91 octane is the highest I can get at regular gas stations, mixed with race gas (110 octane) or booster in my '65 GTO (stock compression or a little higher), and the cheapest slop I can get in my '67 GTO that I set at 9:1 compression. My buddy with a freshly restored, stock '67 GTO is running the 110 too, but at a higher ratio than I am. My '65 seems to be ok at about what I estimate to be 98 octane. Mainly because it's hot and dry out here. If it were cooler or more humid, I think a little less octane would be ok. Quite a few guys in colder climates where 93 octane is available seem to be ok with stock-ish compression. Doesn't work in CA.
 

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I am wondering what octane you guys are running in your cars. I am especially interested in what octane you are running if you have mainly stock engines. Also, do you guys use any fuel additives?

Thanks!
I built my motor intentionally to be happy on 93 octane, but it's not stock. My static compression ratio is 9.46:1 and I'm running "factory" iron heads.

Bear
 

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I run 93 Octane, which is highest I can get in the Houston area. So far I haven't used any additives, but I haven't driven the GTO in hot summer weather either (been gone all summer).
I use ExxonMobil gas exclusively, mainly because I work for ExxonMobil, but also because the gas seems to last longer than the Valero gas I used to buy (closest place to the house). My Corvette is particularly sensitive to old gas, and the Valero stuff would make it start to run poorly after just a couple of weeks. I also started putting StaBil in the tanks if I'm going to be gone or not driving the cars for a while for whatever reason. They (StaBil) make a new formulation that is supposed to help with the higher alcohol content fuels that are being sold these days.
 

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I use shell 93 octane with Lucas oil fuel treatment (upper cylinder lubricant & fuel system cleaner). It replaces the lubricating properties that were stripped from gasoline when they removed the lead.

I'm from New England so in the off season when I'm not driving the car I stabilize the gas with K100-MG which I've used for years in my boat and it is by far the best stabilizer available but very expensive compared to others. I use the MG(marine gas) instead of the G(gas) because it has even a more advance stabilizer and prevents ethanol phase separation.
 

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I run 100 av fuel in the Camaro all the time in St. Louis. It smells nice and sweet when it comes out the tail pipe. When I lived in Indy it was called Turbo Blue. I ran it every so often but then again there was 94 octane as premium and the gas house had lead gas still at one pump. 1987.

I have looked over changing the cars with higher compression over to E85 as there are many places to get it now. One of the car mags did an article on it back around 2002, give or take a couple years. They said it wasn't worth it then, now one of them has said it is a good idea. Running SS lines and getting alky tolerant soft lines is not to bad in price, and pretty straight forward to install. The carb is the only real money and or leg work to get it right. Extreme 4X4 on spike TV did it to an old scout with a TBI and learning computer from Affordable Fuel Injection - Latest News. It will adjust for blended E85 and petrol. That is more then I would like to spend since I have 4 cars that I would consider to do it to, or 1 exhaust system for Eirc:seeya:. If I had one car I would be all over it. What I am looking for is to keep it down to $300 a car. It sounds great and keeps me thinking about doing it, but to spend has much as my next project for 4 cars to run it TBI style is a bit pricey. For cars that get used on limited days of the year. The gas will sour before it is used up in some.
Now another idea would be to get all the cars wired and plumbed for 1 TBI and computer and just swap them out to the car I would like to drive. There is a learning cycle on the computer, so It will be a pain in the ass.
I really like hearing from Thumping on this. Nothing better then straight from real cars running on it by real drives. Any one can slap some new stuff together and run it around on some trailer queen in little runs on tracks and car shows for years with out trouble. It's all together different really cruising it and having the car for years with out trouble.
 

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105 octane E85. Building a 13:1 455 to run on it, and raising the compression in the 70 GTOs 455 to 11.7:1. Its cheaper than pump gas and gives better performance than race gas. Its the way to go if you have a high compression street engine or some kind of forced induction.

Since regular is $3.60 here and premium is $3.88 E85 for $2.75 is a bargain. Everything I own is going to get converted to run on it. With the old cars all it takes is carb mods. No need for stainless fuel lines, that is overkill and only needed for methanol, not ethanol. With the new ones it takes injectors and some computer tuning. People dont like it, but that is because they dont know about it first hand, they are just going off what others tell them. Enjoy the pump gas while you can afford it, I will never run out since I make ethanol in my back yard. :)
 

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When my friend ran his '67 on pure methanol back in the late '70's, he used his Q-jet. I believe he said he simply removed the jets and changed out the metering rods. Said it ran GREAT. But he could only go like 100 miles on a full tank of alky. I think running ethanol you would run the stock intake and just re-jet the carb(s) much richer. Not a big $$$.
 

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I am a huge do it myself guy. So I am looking at what it takes to redo a Qjet and Holley. There is many options, kits, and places that will change a Holley over. The Qjet is not as straightforward, at least it isn't being written about how or even kits/ part to run it. Meth is like 2x more fuel then gas and Elthy is 1.6x. The trouble with the Qjet that I have read so far, is the Idle circuit is in need of modification, as it doesn't feed enough fuel. The idle screw almost falls out from how far you have to unscrew them. It is still a carb and it is about orifice size on air bleed and fuel bleed. So it is just a matter of opening it up to the right diameter.
I am just going by what I have read and know less then nothing about this in real life. So If I am saying something that is wrong please forgive my ignorance.

One thing to point out here is that Ford was going to make his cars run on Ethy way back when horse crap filled roads where the norm. Even better is that ethy is what fueled the Shine runners and began Nascar. So this isn't just something new and it has been done long in the past and very well to boot.

There is more to it then just cut and dry don't get me wrong. For around $400 more or less a street ran carb can be modified by Mark Sullen's E85 Carburetor Conversions you have to provide the carb. Most Holley kits are like $225 to $300 anyway to get it up to E85. So what he is charging is a very good price.
It is like back in the 80's when porting heads at speed shop's was some sort of mega secret. No one wanted to tell how they are getting real power. Nothing wrong with getting paid for what you know and the skills you use to make it happen.

But once again I like to do things myself and ask around to get help when I am stuck.


What do you do Thump? Do you mod the carbs yourself or have them sent to be tuned?
 

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As far as I know I am the only guy doing Qjet conversions. I am still working out the bugs and learning what it takes to make them run very well, but getting it to run on ethanol is easy. I am doing two more of them right now, one for me and one for a friend. I have a numbered drill set and I open everything up with that.

The first one came out ok, its on the 70 right now, but I need to do some more work and testing with it, and finish the secondary side of it. The weather is warming up now so things will progress faster. When I do the next carb I will take pics and write up what I am doing so I can share the info with others. Im not looking to make money doing it so I will share what I find, I would rather car guys get to enjoy their muscle car and actually be able to drive it.

I wish Cliff Ruggles would get in on ethanol conversions, but he isnt ready to at this point. He does provide me with parts and knowledge though, and he has been lots of help with this project.


Mark does great work on Holley carbs, I am going to have him do the 1050 on my drag car. I would do it but the boosters need swapped and I dont have the tool to do that. I have a couple other Holley carbs I am converting to run on my Fords, going to do those soon as well. I havent driven my 67 Cougar since 1987, and I been itching to get it out again.

The fuel systems are pretty much stock as far as lines, and the rubber hoses are ethanol compatible just like any fuel line you buy at a parts store today. It has to be because so much of our gas has 10% in it now. If it can handle 10% ethanol it can handle 100% in the system.

The 13:1 455 is all here now, just waiting on an engine stand to assemble it if I can ever get done working on the winter beaters. It might find its way into the GTO, but the plans are to stuff it in a 79 Trans Am. The TA has 2.41 gears in it and a 550hp 455 shouldnt have a problem moving it, the idea is to see how far I can go on a gallon of fuel. That will tell me how much mileage we pick up by raising the compression and camming it to make max torque between idle and 5000 rpm. Everything I do is low buck so it can be copied by practically anyone.
 

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The more i read about this the more i am thinking about converting my 463 to E-85, readily available here, and at around 2.60 gallon is around a dollar cheaper than 93. As i understand it you have to jet the carb for 30% more flow, the question i have is does this mean you are burning 30% more fuel per mile? 18 MPG on pump would equate to 12 MPG on E-85??? That would make it about a wash as far as any savings at the pump, but i am sure the car would love the added Octane.
 
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