What grade gas should I use in my recently aquired RR

[azmopardude]

Would like some imput on what octane gas I should use and which lead additive is best? also we here in AZ have the MTB and alcohol added to the gas at different times of the year.

 

[mcmopar]

That depends on how it runs. Will it run on regular or mid-grade ok? Back when I had my 1st runner it would run regular in the stock 10:1 compression engine. My present engine has 10.5:1 + compression and with some timing adjustments it runs regular unleaded just fine in everyday driving. If I wanted to romp on it I'd run premium, though. Now that my 383 has the iron 452 heads with hardened valve seats I can use unleaded gas with no issues but 906 heads will need some lead protection to keep the valves from receding into the heads. I used to run Max Lead 2000 to help increase the octane of pump premium but it isn't easy to come by anymore since the distributor went belly up. There is another lead additive called Lead Supreme you might want to check out.
http://www.wildbillscorvette.com/prod01a.htm
This stuff will protect your valves but if your state does roadside emissions tests you better check and see if it is legal there. This is the real tetraethyl lead that used to be added to gasoline back in the muscle car heydays.

 

[Roadcuda]

I run regular unleaded in my car, a stock 383, with no problems, and no pinging.

 

[Basketcase]

I've always run the cheap stuff without problems. but mine have been stock.

 

[mannye]

That depends on how it runs. Will it run on regular or mid-grade ok? Back when I had my 1st runner it would run regular in the stock 10:1 compression engine. My present engine has 10.5:1 + compression and with some timing adjustments it runs regular unleaded just fine in everyday driving. If I wanted to romp on it I'd run premium, though. Now that my 383 has the iron 452 heads with hardened valve seats I can use unleaded gas with no issues but 906 heads will need some lead protection to keep the valves from receding into the heads. I used to run Max Lead 2000 to help increase the octane of pump premium but it isn't easy to come by anymore since the distributor went belly up. There is another lead additive called Lead Supreme you might want to check out.
http://www.wildbillscorvette.com/prod01a.htm
This stuff will protect your valves but if your state does roadside emissions tests you better check and see if it is legal there. This is the real tetraethyl lead that used to be added to gasoline back in the muscle car heydays.

Looks like it's also gone. The product is currently unavailable.

 

[SomeCarGuy]

You don't want to breath in real lead anyway. That is some SERIOUSLY bad stuff.

I run 93 in my car, never tried anythign else. I figure it costs less than 100 a year extra to run the good stuff versus lesser grades.

 

[69hemibeep]

You don't want to breath in real lead anyway. That is some SERIOUSLY bad stuff.

I run 93 in my car, never tried anythign else. I figure it costs less than 100 a year extra to run the good stuff versus lesser grades.

Oh come on, us older guys grew up with that stuff and didn't suffer any brain,,,what was I talking about :basketcase:

 

[mcmopar]

If you are running unleaded gas in engines with original 906 heads without lead or some sort of lead substitute you are experiencing valve seat recession period. I've seen firsthand what running unleaded gas can do to heads without hardened seats and trust me - it ain't pretty. If you are running original heads with unleaded gas it's a good idea to:
1). Run an additive to help protect the exhaust valve seats.
2). Have hardened valve seats installed in your heads.
-or-
3). Do what I did and find a set of heads with hardened seats from the factory. Late model 346 castings and all 452 castings have induction hardened seats from the factory. It's not pretty to see valves receded into the head by 1/4" or so. :cents:

 

[azmopardude]

Yea I did some checking and I think I'll run the blue AV gas it's 100 octane and low lead it also has fuel stablizer in it so it safe to leave set for long periods, thats the upside the downside is $4.50 gal.

 

[Jim S.]

Well here is what I do. Maybe it is totally wrong but, that is just me. I am lucky, I have a Citgo station nearby that has 110 leaded race gas. I mix that 50/50 with 92 unleaded non-oxy. That brings me to 100 octane give or take. I have no idea if this engine has hardened valve seats or not. I still run points and a condenser because I like it that way. I do not have a fancy dial timing light or have ever installed timing tape on the damper. I just do it the old school way. Rev the engine and turn the distributor until it knocks. Then back it off. Take the car out under load and beat on it. If it still knocks, back the dist. off a little. Best guess with the timing light is that I am at 13 to 16 degrees advanced initial because it is off the scale. Car runs great with no hesitation and the smell of leaded race gas is great. At least that is what I was told before the brain cells fried.

 

[mcmopar]

You could probably run 2/3 93 unleaded and 1/3 leaded race gas because mixing the two actually enhances the octane effect and would cost a bit less. As it is, 50-50 is fine. I used to mix leaded regular and unleaded premium back in 1981-82 until leaded gas was outlawed. Your valves will be fine mixing in the leaded race gas. And yes, it do smell mighty good!

 

[Basketcase]

Well here is what I do. Maybe it is totally wrong but, that is just me. I am lucky, I have a Citgo station nearby that has 110 leaded race gas. I mix that 50/50 with 92 unleaded non-oxy. That brings me to 100 octane give or take. I have no idea if this engine has hardened valve seats or not. I still run points and a condenser because I like it that way. I do not have a fancy dial timing light or have ever installed timing tape on the damper. I just do it the old school way. Rev the engine and turn the distributor until it knocks. Then back it off. Take the car out under load and beat on it. If it still knocks, back the dist. off a little. Best guess with the timing light is that I am at 13 to 16 degrees advanced initial because it is off the scale. Car runs great with no hesitation and the smell of leaded race gas is great. At least that is what I was told before the brain cells fried.

Jim I'm glad I'm not the only one that does it that way. I do have a light, but this is how I did it before I had one. There is a Marathon Station here that has 110 Sunoco, they keep a padlock on it. the last time I noticed, it was at least $7 a gallon....