64 Gasoline Requirements

[GeoBurns]

Now that I have my key problem resolved thanks to Joliet Studebaker, I need to address the running of the car.

What if anything needs to be done to make the car run safely with todays unleaded fuel? Additives - how often? Not looking to do any mechanical mods right now.

I have searched the forums and I cannot find any info.

Edited May 27, 2007 by GeoBurns

[Gunslinger]

Now that I have my key problem resolved thanks to Joliet Studebaker, I need to address the running of the car.

What if anything needs to be done to make the car run safely with todays unleaded fuel? Additives - how often? Not looking to do any mechanical mods right now.

I have searched the forums and I cannot find any info.

There seems to be a lot of controversy with an answer to your question and everyone seems to have a different opinion with just as many conflicting bits of evidence.

Octane ratings are figured differently now than when Stude originally built your car. If you have an R1 with it's rated 10.25-1 compression ratio you still need premium grade gasoline. R2's have a lower compression ration but with the supercharger they still need the high octane stuff to combat detonation...so, unless you've significantly lowered your compression ratio from stock, an Avanti still needs the high octane...leaded or unleaded. These cars aren't like modern cars with computerized ignitions that can automatically adjust timing when it detects engine knock due to use of lower than specified octane fuel.

About all you can find now, outside of racing fuels or aviation fuel, is 92 or 93 octane unleaded. The lead originally used in gasoline was a cheap valve lubricant, that's why it was used. Allegedly the use of unleaded gas in older engines...built prior to about '71 or '72, can cause damage to valve seats. Since that time manufacturers have installed or built in hardened valve seats into cylinder heads to keep that from happening. If your cylinder heads have been rebuilt since that time period, they may well have hardened valve seats installled...it's pretty much done automatically.

Even if your engine has never been rebuilt, you would likely never experience problems, especially if you don't drive your car hard and keep it in proper state of tune. You can still put additives in it to help. There are lead substitutes on the market and upper cylinder lubes. You'll find people swearing by or at different brands. Go to auto supply stores and see what's available and read the instructions. Try it and see.

I have a '69 Corvette with a 427 engine with a rated 11:1 compression ratio. When the engine was rebuilt the compression ratio was lowered to 10.6:1 and I have noticed no detonation issues with 93 octane pump gas. I do add upper cylinder lube occasionally but I don't know if it does anything...it's more of a peace of mind thing I guess.

[tsterkel]

Ran my "new" '63 R2 from Seattle to North Texas, 2300+ miles, 3 days, using Chevron Supreme. No additives after the first 800 miles (Techron on the chance that I had issues with deposits).

Absolutely no problems, except when I had to use other brands. As a side note, after about 800 miles on the Chevron, the engine "loosened up" and ran smoother, and accelerated better.

There seems to be a lot of controversy with an answer to your question and everyone seems to have a different opinion with just as many conflicting bits of evidence.

Octane ratings are figured differently now than when Stude originally built your car. If you have an R1 with it's rated 10.25-1 compression ratio you still need premium grade gasoline. R2's have a lower compression ration but with the supercharger they still need the high octane stuff to combat detonation...so, unless you've significantly lowered your compression ratio from stock, an Avanti still needs the high octane...leaded or unleaded. These cars aren't like modern cars with computerized ignitions that can automatically adjust timing when it detects engine knock due to use of lower than specified octane fuel.

About all you can find now, outside of racing fuels or aviation fuel, is 92 or 93 octane unleaded. The lead originally used in gasoline was a cheap valve lubricant, that's why it was used. Allegedly the use of unleaded gas in older engines...built prior to about '71 or '72, can cause damage to valve seats. Since that time manufacturers have installed or built in hardened valve seats into cylinder heads to keep that from happening. If your cylinder heads have been rebuilt since that time period, they may well have hardened valve seats installled...it's pretty much done automatically.

Even if your engine has never been rebuilt, you would likely never experience problems, especially if you don't drive your car hard and keep it in proper state of tune. You can still put additives in it to help. There are lead substitutes on the market and upper cylinder lubes. You'll find people swearing by or at different brands. Go to auto supply stores and see what's available and read the instructions. Try it and see.

I have a '69 Corvette with a 427 engine with a rated 11:1 compression ratio. When the engine was rebuilt the compression ratio was lowered to 10.6:1 and I have noticed no detonation issues with 93 octane pump gas. I do add upper cylinder lube occasionally but I don't know if it does anything...it's more of a peace of mind thing I guess.

[yovendoelcafe]

Now that I have my key problem resolved thanks to Joliet Studebaker, I need to address the running of the car.

What if anything needs to be done to make the car run safely with todays unleaded fuel? Additives - how often? Not looking to do any mechanical mods right now.

I have searched the forums and I cannot find any info.

If your Avanti is an R-1 example, I believe it's 10:25:1 compression ratio is beyond the ability of today's pump fuel to prevent 'ping' and valve recission...I am utilizing Sunoco 110 leaded fuel...it is the only fuel I have found that prevents 'ping' in my R-1.......especially during the high heat of the summer months...that being said.....there are companies still marketing TEL in qt. containers....do a web search, you will find several...I have found that after talks with Sunoco's racing division in Marcus Hook, Pa...my R-1 needs apx 4-5 gallons of their 110 leaded product mixed in with 15 gallons of pump grade fuel.

Unfortunately, it's only a matter of time before the 'beltway genius's' under pressure from environmentalists force the end of the Cam-2 product and the TEL additive now available in qts.....it may be a good idea to de-tune the engine and fit standard Stude V-8 heads....with hardened seats.

[fmarshall]

Now that I have my key problem resolved thanks to Joliet Studebaker, I need to address the running of the car.

What if anything needs to be done to make the car run safely with todays unleaded fuel? Additives - how often? Not looking to do any mechanical mods right now.

I have searched the forums and I cannot find any info.

IMO, the only things that you need to worry about, aside from any seals/gaskets effected by today's gas, is octane and valve lubrication. Lead served the lubrication purpose along with the octane.

Nowadays, the way to "fix" the valve issue is to install hardened seats. I did read on the SDC forums where one guy has had great luck with just adjusting his valves at half the recommended service interval to compensate for the lack of lead. And, if the environment isn't your concern, there are places to buy lead.

Octane can be had for $$. VP Racing Fuel makes a StreetBlaze that is formulated for American Mucle. It is 100 Octane and can be obtained in 5 Gallon Cans. It's not cheap; but it will richen the fule suitably, should you get any detonation from pump gas. VP also makes a 112 Leaded fuel.

If you can buy 112 for use at the race track, which is right next to the highway, you think that "bad" air stays put?? I don't.