Fuel

[x33rs]

I run the same 91 octane here in Arizona in all the cars.

The 69 Z with 11:1 compression my wife daily drives for the last 6 years and it's had nothing but 91 octane. My 70 Formula with 10.13:1 compression is the same and I drive that one nearly everyday myself.

We have a few other cars with high compression that also use nothing but 91 octane, one of them makes 724 hp on it, on motor alone.

When I built these engines I took steps to make sure the higher compression would live on the cat pee we have at the pumps by doing things like making sure the pistons are at zero deck for tight quench, degreeing the camshaft so intake valve opening is about .030-.035" more than exhaust at TDC overlap stroke, hardened seats, stainless valves, and a bunch of time, usually on a dyno, with tuning the carbs and dialing in a good ignition curve with proper vacuum advance etc....because I don't like to give up power either. Going through this isn't a cheap endeavor and may not be an option for those with survivor cars, but it's what I do to make these cars live with what's easily available while still maintaining what makes these engines so great.

I started building engines like this more than 20 years ago simply because mixing fuel had already started to become a problem and way too expensive even back then. I can't even imagine going through that now. Plus we drive our classics daily, everywhere. They have to run what ever I can find at the pumps.

[big gear head]

I retard the timing on mine when I run pump gas. It makes a little less power, but it doesn't damage itself. I use recreational gas on the street. It doesn't have any alcohol in it, so I don't get vapor lock.

[60sStuff]

I have a place close by that sells race fuel.

I’ll take a couple GI 5 gal. cans and fill with 110 and mix 50-50 with the 91 octane pump gas.

They like it.

[bilede]

Loves truck stop in Chandler has 103 and 110 octane racing fuel for sale at the pump. Can get to it by heading south of Chandler Blvd on 56th St about 2 miles if you want to avoid freeways or take I-10 south to the Wild horse pass exit and its on east side of freeway.

[martyb]

Thanks for all the feedback! I’m 1 mile from the Chandler Airport, going to see if I can get some AV fuel there. If not I’ll head to Loves and pay their crazy high prices. Been there with my Viper for some 100 octane.

AZ guys, any recommendations locally for a good thorough tune up?

[Pro Stock John]

Plus you can get a couple 5 gallon fuel jugs and keep a little on hand.

[Flying Undertaker]

I use VP C-12 and mix it with 91, 92 octane pump gas. Your car will tell you what the right ratio to mix it with for best results.

[Pro Stock John]

What is the rating of this av gas, web says it's all 100 octane?

[martyb]

Originally Posted by Pro Stock John

What is the rating of this av gas, web says it's all 100 octane?

Correct, 100 octane.

[Chuck_Burg]

I mix 5 gallons of VP or Sunoco 110 leaded in with California 91 octane in our stone stock 67 L78. ZERO pinging, not even with 38* total timing but I keep it at 36*.. Works good, smells better... We don't drive it too much, once or twice a month.