FUEL FOR A BB 65 396/425

[Marc N.]

good morning,

need some help here....recently bought a bb vette from texas....after having the car for a month already, just used the full tank that came with it. car was running real strong, and yesterday I put some shell 91 california high test gas into it...felt a slight hesitation and also when I turned the car off, it kept running. Is this caused by not using higher octane gas or lead additive or higher octane gas???? Not yet sure if the engine during its rebuilding was changed over to run on unleaded.....just by what I discribed...what do you guys think?....advise and thanks, marc / southern cal

[Mike L.]

Re: FUEL FOR A BB 65 396/425

Go buy a 55gal. drum of Sunoco Blue 112 oct. racing fuel and mix it with the gas you are using, things WILL get better.

[Marc N.]

Re: FUEL FOR A BB 65 396/425

THANKS MIKE BUT THEY DO NOT SELL SUNOCO GAS OUT ON THE WEST COAST

[Joel Falk]

Re: FUEL FOR A BB 65 396/425

Marc,

Engine run-on is one side effect of too low of an octane for your vehicle configuration. A more serious side effect is detonation (engine knock--it basically sounds like run-on except the engine is already running). In either case, you can try retarding the engine timing to see if that reduces the run-on and detonation. After tinkering with the timing, a lot of people have Corvettes that run just fine on 92 or 93, so if it is available in CA try using it.

Worst case, various companies (Jack Podell, Kemco, probably many others as well) sell fuel additives that boost ocatane. You could also try mixing aviation gas (leaded 110 octane) with your commercially available gas and try and get it to improve. I use Kemco's Lead Supreme 130 in a small qty to get a couple of extra octane points (for "off-road use only!"). It works well and is pretty reasonably priced when used in moderation. I've also heard of people mixing Xylene or Toluene with their pump gas to boost octane, but this might get expensive if you don't have a large supply house to buy from.

Good luck.

[Joel Falk]

Re: FUEL FOR A BB 65 396/425

And easy on the caps lock! *NM*

[Richard S.]

Re: FUEL FOR A BB 65 396/425

Very interesting thread....over the last six weeks or so I've noticed that both my 66 and 67 big blocks do not seem to be running as well as they once did on the highest octane I can buy....now even my 89 is detonating and it's only ever been fed the highest octane available and always ran fine.....I'm wondering if the gas stations might be selling "regular" as high octane....any thoughts....

[Richard D.]

Re: FUEL FOR A BB 65 396/425

Some interesting links on octane boosting and race gas analysis and recommendations I thought you guys might find useful.

I do not do any of these things (yet) as my 11:0 L79 seems to do pretty well on Sunoco 94 (live in NJ).

I also like to run pure Techron (Chevron makes it pure) about a 20oz. bottle for $10.00 or so, once or twice a year in all my cars.

http://www.gnttype.org/techarea/misc/octaneexplained.html

http://www.idavette.net/hib/fuel/page2.htm

http://www.hotrod.com/techarticles/72498

Do a Goolgle search for Octane Boosting and you'll get a lot more info.

Regards,

Rich

[Tom M.]

Re: FUEL FOR A BB 65 396/425 Rick Snow

Rick, I believe you live in Canada right? You might check the methanol level were you are regularly buying gas, some areas have different levels I have noticed, and in the winter I have taken a friends Dually up there and his gas gage wouln't read the level of fuel in it.

Tom

[Chris H.]

Re: FUEL FOR A BB 65 396/425

I'm sure you should be able to locate some racing fuel out there somehow. Contact your local race track and see where the racers get their fuel.

Here in northeastern MA there is a local Haffner's station that sells CAM2 110 leaded for $4.50/gallon to all the drag racers headed to New England Dragway. "For Off Road Use Only" ofcourse;>

[Richard S.]

Re: FUEL FOR A BB 65 396/425 Rick Snow

Tom,
Yes...I'm in Montreal....I've tried several different brands...all the highest octane sold here and in the U.S.....cars run fine when I add a bottle of 104 octane boost. I drive a lot and fill up at highway service centers quite often....these service centers seem to be the worst for getting poor performance out of their highest octane pumps. Most of the time I'll probably never be back to that service center on that highway...like most travellers I guess...especially on U.S. Interstates.....so, I'm suspecting these gas stations are not really giving us high octane out of high octane designated pumps and making more profit. What with the war and the oil prices it all seems to coincidental.....I mean even my 89 was detonating on the drve home from Windsor and it's designed to run on todays high octane....something does not add up.....

[Donald T.]

Re: FUEL FOR A BB 65 396/425 Rick Snow

I believe in the US gas is regulated by the Dept. of Weights and Measures. They inspect the pumps to verify the pump is accurate and octane is at least what is specified on the pump. There should be a sticker on the pump with the date of the last inspection. If you suspect a station is selling lower octane than advertised, you can contact your local Dept. of Weights and Measures. I remember years ago a local gas station was busted for selling the low octane in all their pumps regardless of advertised octane. They received big fines and lots of bad publicity from the local media. I can't imagine a gas station risking that, but ya never know!

[Joel Falk]

Re: FUEL FOR A BB 65 396/425 Rick Snow

I work for a large oil company and find it highly unlikely that stations from any major brand would or could pull a switch with fuels. There are too many people who would need to be involved in the scheme to make it workable, and because of that I think the info would get leaked to the public. Most of the larger, newer stations are company owned, so your Shells, Exxons, BPs don't want to get involved in these shenanigans and risk their reputations for what amounts to pennies per gallon. It is possible that smaller, independently owned and operated stations might be able to do something like this, but I think it is unlikely.

[Warren F.]

Re: FUEL FOR A BB 65 396/425

Marc:

Welcome to California's reformulated crappy premium fuel. That is why your big block isn't running quite right. Unocal 76 stations sometime have racing fuel in small containers that they will sell to you. Otherwise at Infineon Raceway near Vallejo, Ca has a station that you can pull up to and get 6 different grades right out of the pumps, ie: 94,98,102,110,114,118 octane ratings. Prices run from $4.75 a gal to $8.50 a gal.