Octane requirment

[Douglas Money]

In the Chicagoland area in 1979, regular gas was 89 octane.

[xsrider]

Yes, but what about unleaded... these engines were designed to run on leaded regular, and the lead part lubricates the valve guides and stems etc.... anyone have some experience to share?

[trbig]

At the local YammyHammer shop, they have some leaded racing fuel that's rated at 110 octane... I also know a local station that has unleaded racing fuel grades of 100, 105, and 110. It's about 7 bucks a gallon, but have been tempted at times to fill up and see what happens. Is there a possibility of too high octane?

Tod

[randy]

I don't know, in the mid-70's when Sunoco still sold their 260, whenever i used it seemed it made a difference. maybe it was my imagination?

Anyone else remember Sunoco 260? IIRC, the octane was 102 right outta the pump.

[Douglas Money]

Higher octane requires more timing. If you don't advance the timing to take care of the higher octane you will see only a slight to no improvement.

[Douglas Money]

BTW, the lead is only to cushion the valve seats and faces for high valve spring pressure. The hardened valves used today do not need the lead. I don't know what the 1100 used in this case.

[scott0757]

Not only do I remember Sunoco 260 I remember pumping it for a summer job. You could rorate the grade setting from 86 up to 260. Does anyone remember the Sunoco CAM2 racing fuel???