What fuel do you use?

[Pappy]

Just wondering what you folks use in your older vettes for fuel? do you add lead additives or octaine booster to your fuel?

 

[MaineShark]

How old do you mean? As of 1971, all 'Vettes were designed to operate on unleaded fuel. So, no lead additive or octane boost needed in 1971 and later cars.

Now, as for my car, I run regular ol' 87-octane pump gas. 9:1 compression doesn't need any more than that. Every fourth tank (approximately), I add a bottle of cleaner (fuel injector cleaner will work, although some brands have carbeurator-specific formulas).

Joe

 

[Pappy]

pre 71

 

[Vette/Berlina-coupe]

-what ever is the cheapist! -apparently soon to be $3-gal.; -so there will be a lot us learning to shut-off the engine at long traffic-lights. Have sbV8 w/TwistedWedge(Summit) 10:1-cr alum.heads, and demand-activated Water-injector (use of alcohol optional for higher performance)... Bob vH
ad :dance

 

[WayneLBurnham]

93 Octane or it SITS THERE!

For SHAME Maine Shark!

87 octane with 9:1 CR on old iron heads? You're kidding me, right? Or have you upgraded your heads/retarded timing?

That medium grade 89/90 might be - might be OK, but why chance holing a piston with detonation?

I NEVER put that junk in my tanks - on any car I own. Never have/never will.

As for octane booster, my crate engine doesn't get have even that high a CR probably and doesn't need it.

There is an interesting thread somewhere here about a month back on octane boosters. I don't actually concur with all the points raised there, but many were good and all were well considered. You might do a search for it. I used it on my Blazer with 10.25:1 flat tops, but foolishly stopped when I installed a Spearco water injector, which never used up any water and thus cratered the heads or pistons.

I throw in a can of cleaner/dewaterer every now and then, other than that
ANY 91/93 "Premium" gas from a reputable station.

 

[Scott81]

Depends what motor you have and what the compression is, iron or aluminum heads. I know some guys with the big block cars use a lead additive but still complain about pinging/detonation. If you have a good speed shop or gas station in the area you should be able to get leaded high octane gas, be warned though it's pretty expensive. I can get both CAM-2 in 100 or 110 octane, I think CAM-2 is a Sunoco brand. The 110 octane CAM-2 runs $20 for 5 gallons. I can also get VP Racing Fuel locally, C-12 leaded 108 octane runs about $27 for 5 gallons. Both retailers require you to have a container to put it in as you can't pump it directly into a car, nor can you pour it into your car from the container at their location.

I have a 383 stroker with 10.5 compression, I add 5 gallons of high octane leaded with each tank full of 93 premium.

Talking with the local racers they recommend using the fuel over additives, what I was told is that the octane boosters over time will create a build up of gunk where the fuel runs/burns cleaner.

The other benefit of running the high octane is the way it burns, it's a more even burn where the fuels from the local gas station is more of an explosion putting more stress on the motor internals.

This is all info I was told, I'm by no means the tech guy on fuel.

http://www.vpracingfuels.com/ VP Racing Fuel

http://www.racegas.com/ Sunoco Racing Gas

http://www.racegas.com/gt100locals/default.asp CAM-2

 

[BBB454]

The guy I bought mine from recommended that I use lead additive because of the way the engine was rebuilt (of course I can't remember exactly what he said).

So I have been using it for the most part, but it seems like it's getting harder & harder to find (and some of them say "for off-road use only"). Oh well, I use it anyway :L

Barb

 

[MaineShark]

87 octane is more than enough to prevent pinging/detonation in an engine with 9:1 compression, even with iron heads. Now, an engine with higher compression, forced induction, or an oddly-shaped combustion chamber might require more, but 87 is all we need.

The only possible reason to use higher-octane fuel in this engine is the additives that are included, which can keep things cleaner. But, a bottle of cleaner every few tanks is far more cost-effective, and may even be better at cleaning.

Remember, octane is bad for your engine, and bad for your performance. Only use what's necessary - any more is detrimental. I was in the station the other day, and watched someone fill a Pontiac 6000 station wagon with 93, at $1.90/gallon. Amusing to see people waste money like that.

To answer Pappy's questions: yeah, you need lead substitute to protect your internals: they were designed to have the lubrication that the lead provides. Depending on exactly which engine you get, will determine exactly what octane you need, and whether you need octane boost (or adding some race gas to each tank, as Scott suggested).

I know a guy with a '69 Camaro, and he's getting so fed up with the cost and hassle of running all those additives that he is planning on an engine swap with a more modern engine.

Joe

 

[intex99]

I just got a 69 Chevelle(4dr)with a 307 and asked about what gas I should use in it.I was told the lead additive was more for the valve seals than anything else so I throw a bottle in every fillup.I don't know if the last owner ever did that or not but haven't had any pinging so far.But in that car I use the 87 octane .
Just my 2 cents worth

 

[Dave L.]

Texaco 89.

Dave

 

[ratdog]

In my 69 427/390 I use Sunoco purple racing fuel. I use it straight with no mixing. A 55 gallon drum lasts me about 3 yrs.

 

[silver 80]

ratdog,
do you add any stablizers to the fuel? three years seems to be a long time for fuel?

 

[ratdog]

I don't put any in the 55 gal drum, although every winter I do all my cars. I think someone told me once that leaded gas doesn't go bad like the unleaded stuff, who knows ?!?!?!?!

 

[Robert N]

I run a mix of 91 Octane and 100 octane racing fuel.

 

[jonstr]

With 12:1 compression, I pretty much have to run 110 octane leaded racing fuel in my '69 L88. There's a local 76 station that sells it out of their garage, but I'm about to go the 55 gallon drum route like ratdog.

My '63 gets unleaded premium. No additives (I had hardened valve seats put in).

 

[huladick]

I always use 91 octane. Might run OK on less, but never any trouble with the 91.

 

[Rowdy1]

94 Sunoco

I've been using that since the engine was built and never had a problem. I can idle or cruise all day and not have a miss, or jump on it to 7 grand in every gear. I'm running 12 1/2 to 1 compression, 64 CC aluminum heads.