Octane Solution
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Drifting
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Octane Solution
Brand newbie here. I haven't even taken possession yet, but have a nice original 1962 with 327/300 (Carter AFB I believe) coming in a few weeks. Didn't think about this until now, but what octane gas do I need to burn in this beast. I know unleaded gas if okay for these early engines, but original documents say 95/96 octane gas and that is impossible to find in OK. Suggestions or education would be appreciated.
Butch
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Should run easily on 93 octane. Keep it cool and tuned and it will do fine.
JIM
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Drifting
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Thanks Jim! 91 octane is about the best we can find around here unless you pay $5.00 gallon for 93 and it's about 60 miles round trip. Can I burn the 91 and add some octane booster? This is not a daily driver and will see maybe 1000 miles a year.
Butch
Butch
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You can probably burn 89 octane in your car. Use the lowest octane you can without detonation for the most power. Octane does NOT add power....it just retards the burn speed of the fuel. The only octane boosters that work are tetraethyl lead (Octane Supreme 130) and Tuolulene (Sp?). The '104' and '108' stuff is an absolute ruse. Useless.
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Brand newbie here. I haven't even taken possession yet, but have a nice original 1962 with 327/300 (Carter AFB I believe) coming in a few weeks. Didn't think about this until now, but what octane gas do I need to burn in this beast. I know unleaded gas if okay for these early engines, but original documents say 95/96 octane gas and that is impossible to find in OK. Suggestions or education would be appreciated.
Butch
Butch
When the Owners Manual was written for your car, the gasoline octane was specified in Research Octane numbers. Sometime in the 1970's I believe, all gasoline ratings in the US went to Pump Octane or Research Octane + Motor Octane /2. These are the same number. When this rating change occurred, the octane rating at the pumps dropped by about 4 to 5 points for the SAME octane gasoline.
So your old 95-96 number (Research Octane) just became 91-92 Pump Octane (or (R+M)/2) ).
The discussion above assumes that your compression ratio, cam specs, and distributor advance curve remain as original. Changes to these will effect the octane rating the engine actually needs.
I would start with 91 or 93 octane and then go down to 89 and see how the car performs. Keep the tank level low when reducing the octane just in case you need to go back up quickly. Also verify initial, centrifugal, and vacuum advance specs against OEM so you know what you have.
FWIW.
Larry
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You can probably burn 89 octane in your car. Use the lowest octane you can without detonation for the most power. Octane does NOT add power....it just retards the burn speed of the fuel. The only octane boosters that work are tetraethyl lead (Octane Supreme 130) and Tuolulene (Sp?). The '104' and '108' stuff is an absolute ruse. Useless.
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Brand newbie here. I haven't even taken possession yet, but have a nice original 1962 with 327/300 (Carter AFB I believe) coming in a few weeks. Didn't think about this until now, but what octane gas do I need to burn in this beast. I know unleaded gas if okay for these early engines, but original documents say 95/96 octane gas and that is impossible to find in OK. Suggestions or education would be appreciated.
Butch
Butch
Last edited by mrtexas; Mar 26, 2018 at 09:48 PM.
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When I live in Utah, 91 was all you could get and I made 1100+ RWHP on it with a little boost.
JIM
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Octane requirements go down by 1 number for every 1,000 feet in elevation.
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Is there any way to detect detonation besides the sound? With side pipes I could never tell if the engine is detonating or not. It cost me a ZZ3 motor.
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Bill
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Army
I ran my dual quad 270hp solid lifter 61 off 87 octane laced with ethanol for 10 years...
Never missed a beat... That or 91 should work superbly in your motor..
Avoid the additives and years from now you won't grow a second head that keeps you up all night arguing...
Never missed a beat... That or 91 should work superbly in your motor..
Avoid the additives and years from now you won't grow a second head that keeps you up all night arguing...
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Drifting
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Thank you to everyone for some really good information. I totally forgot about the octane rating change when unleaded hit the market. This is a stock 327/300 that has about 5000 miles since rebuild so there should be no surprises internally. Excellent information guys and I really appreciate the help.
Had a 1961 that was my daily driver back in 1971, but a pig for originality (paid $750 for the car and $1500 for a hardtop). But, back then all gas was higher octane and at $.27 a gallon I bought Premium (Ethel for you old timers). But, I'm 69 now and this is the 1st classic I've had since 1979. Since this is a bucket dream toy, that will be driven on a very limited basis, I'm hoping the lack of creature comforts isn't too bad.
I'll post photos when I get it. Front seats being rebuilt and upholstered right now, rest of the car looks fantastic.
Butch
Had a 1961 that was my daily driver back in 1971, but a pig for originality (paid $750 for the car and $1500 for a hardtop). But, back then all gas was higher octane and at $.27 a gallon I bought Premium (Ethel for you old timers). But, I'm 69 now and this is the 1st classic I've had since 1979. Since this is a bucket dream toy, that will be driven on a very limited basis, I'm hoping the lack of creature comforts isn't too bad.
I'll post photos when I get it. Front seats being rebuilt and upholstered right now, rest of the car looks fantastic.
Butch
Last edited by Dreaming60’s; Mar 27, 2018 at 08:44 AM.
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Army
People who get a new-to-them C1/C2 get a bit paranoid about gas, oil, grease, jacking up the car, you-name-it...
It'll pass after a bit and you realize its just an old Chevy and a lot tougher than you might think !
It'll pass after a bit and you realize its just an old Chevy and a lot tougher than you might think !
Last edited by Frankie the Fink; Mar 27, 2018 at 08:46 AM.
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Drifting
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Kind of what I remember Frankie. I drove all my cars hard back in the 60's and early 70's, but I also took care of them myself if I broke anything. Amazing what you can learn if you fix your own cars and enjoy it. And, it's amazing how tough those old rides really were.
Butch
Butch