Octane rating..Circa1970

TDW · #1 02-10-2007, 08:45 PM

Anyone know what the octane rating was for regular and premium gas back in the early 70's? Before they went to unleaded. Thanks.

3macs1 · #2 02-10-2007, 08:53 PM

Based on what info I have seen in February 1970 Premium was 100 and regular was 94. When they took the lead out the premium dropped to 94 except for gasoline sold by Amoco but that was only available in the east.

nuch_ss396 · #3 02-10-2007, 10:18 PM

That sounds about right.

TDW · #4 02-11-2007, 01:15 AM

Thanks. Did any of the high compression engines run decent on 94? It seems like I always had to run premium in everything that had any horsepower.

jtower1969 · #5 02-11-2007, 01:40 AM

I found this on Rockett Brand Racing Fuel's web site. This site has alot of information and a real good tech line. A chemist called me back in about an hour.
http://www.rockettbrand.com/technica...rConfusion.pdf

TDW · #6 02-11-2007, 03:21 AM

[ QUOTE ]
I found this on Rockett Brand Racing Fuel's web site. This site has alot of information and a real good tech line. A chemist called me back in about an hour.
http://www.rockettbrand.com/technica...rConfusion.pdf

[/ QUOTE ]

Thanks. Interesting reading.

nuch_ss396 · #7 02-11-2007, 03:33 AM

Tony,

I remember all the SHP guys looking for Sunoco 260,
Super Shell, etc. back in those days. When the first gas
crisis hit, of course everyone went to regular fuel.

If I remember correctly, a lot of the cars were detuned
back then so they could run on regular.

Steve

3macs1 · #8 02-11-2007, 03:52 AM

I only know from 77 on and I think it was not even 94 maybe 87 by then. L-72 hated it, retard the timing and eat plugs, worse in hot weather. However Saturday night was time to eat Dodges and almost all of us kept a drum of avgas behind the barn with a pump.Thinking back it was hard to imagine but true we would go out the the airport and they would fill your drum. No problem. Like to see that today.L-72 liked avgas very much and hated dodges.
We tried that 104 additive many times but it never seemed to make a difference. Maybe just me

jtower1969 · #9 02-11-2007, 05:01 AM

Av gas is wrong for use in a car. It is designed to run at a constant RPM...around 3500 or so. The specific gravity is also diffrent than what is needed to run on land. I was told by Rockett that Sunoco 260 would be about 95 octane by todays test methods. I run 3 or 4 gallons of 110 to a tank of Sunoco 93. (Please note it is illegal to run leaded gas on the street) Not that I would ever do that

The Rockett website has alot of information under http://www.rockettbrand.com/technicals/bulletins.htm

**Salvatore** · #10 02-11-2007, 05:26 AM

Tony, Sunoco 260 was 103 octane. Most regular was 91 octane leaded in those days. We ran Sunoco, Texaco and Shell in our hot rods. Sometimes we used Hess 101 octane. Sunoco 240 was 100 octane. All these were leaded. I run 93 octane in my 69 Z. A true 10.5 to 1 compression ratio. I mix that Jack Podell additive 1 to 1 with my gallons and NEVER have a problem. I am not sure that the Podell stuff is even doing anything. I just sleep better. I pumped gas for many years in those old days.

Sam

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