Octane
 

I was wanting some input on gas octanes. I have a 468 BBC with 14.5 compression. I am running Sonoco Maximal.

The plugs burn with a black to them, but I never have a miss or detonation. They are never a clean brown color like I would like to see. But I have read that if you "over-octane" your not going as fast as you could because the fuel burns slower.

Does this fuel sound like what I should be running? I have thought about changing to Sonoco Supreme next time. Or maybe even changing to a VP brand. I am very scared of damaging the engine by not running enough octane. But either of the above should be fine I believe. I look at the charts of these fuels and am lost. All this specific gravity and Research/Motor Octane stuff gets me LOST!

Also what does this oxygenated stuff mean? Is this something I should be looking for?

Re: Octane
 

Steve, I've recently done some track testing of different fuels ,including Sunoco Maximal. .........I had a very difficult time with the Maximal finding jetting and timing that produced consistant runs. ...Several of my friends who either switched to Maximal or had been running it for a while experianced similar results....I suspect the burn rate of the Maximal may be to slow for your combination ..........My main engine is a 565BBC with 15.7 to1 compression. So far after testing with Sunoco Maximal, Sunoco Supreme ,VPc15 and c14 , the c14 has produced the most power and the most consistant runs. ..........I also have a 468BBC with 15 to1 compression ,and have found it runs best on Sunoco Supreme ,or VP c12 .......Unless you are running at very high altitudes,I'd try the Supreme in the car, if Sunoco is the available fuel in your area ,At 14 to 1you should be safe........I'd be comfortable running VP c12 in a combination like yours. ......Tom

Re: Octane
 

I run a 14:1 490 ci BBC. I am currently running the Sunoco Blue. It runs consistant and burns clean. I used to run VP's C12, but it wouldn't last 2 weeks in the fuel jugs, I was constantly chasing a "miss" (expensive fuel for the mower). Put in fresh fuel, car would run fine. A drum of Sunoco fuel has lasted all season w/o an issue. That and the cost difference made up my mind. On a side note, the Sunoco fuel made 5 more HP on my buddy's 468 vs. the C12.Hope this helps.

Kevin

Re: Octane
 

Thanks guys. I am on my last 15 gallons of Sonoco Maximal so I believe I will try Supreme this next time.