Fuel Additive
Thread Starter
Melting Slicks
Joined: Aug 2004
Posts: 3,151
Likes: 294
From: Opelousas, Lousiana
CI 6-7 & 9 Veteran
Fuel Additive
What type of fuel additive do most of you use on your pre-cat cars. I use a lead replacement and a fuel stabilizer since my car sits up a lot.
I need to buy some more soon and I am wondering what is the best products.
I need to buy some more soon and I am wondering what is the best products.
Last edited by crawfish333; Jun 28, 2017 at 09:50 AM.
Instructor
Joined: Jul 2013
Posts: 104
Likes: 15
From: Bennington VT
I use a combination of Sunoco 110 octane leaded racing fuel (5 gallons) with 10 gallons of 93 octane ethanol free premium gas. The 454 loves the combination. I also use Classic Car Motor Oil formulated for flat tappet cams. http://www.classiccarmotoroil.com/
Any gasoline with ethanol will erode all of the seals in a carburetor over time.
Any gasoline with ethanol will erode all of the seals in a carburetor over time.
Burning Brakes
Joined: Sep 2016
Posts: 935
Likes: 433
From: Dutchess county New York
gas
I add about 1/3 of a can of Sea Foam to each full tank.
Le Mans Master
Joined: Jan 2006
Posts: 6,504
Likes: 139
From: Butler Pa
I don't use anything. What makes you think you need it?
Thread Starter
Melting Slicks
Joined: Aug 2004
Posts: 3,151
Likes: 294
From: Opelousas, Lousiana
CI 6-7 & 9 Veteran
Le Mans Master
Joined: Jan 2006
Posts: 6,504
Likes: 139
From: Butler Pa
If the engine were in a dump truck it might need it. Engines that are constantly under a severe load and are lugged down will suffer from valve recession because of no lead. Car engines don't have this problem.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
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Lead was originally an octane booster only. Any "benefit" was accidental.
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Le Mans Master
Joined: Jun 2006
Posts: 6,399
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From: Tampa Florida
I only use ethanol free gas in my '71 LS5 and all of my lawn equipment, pressure washer, etc. The Corvette is a storage tank for the ethanol free gas, I siphon some out for the lawn equipment as needed. 
Burning Brakes
Joined: Sep 2016
Posts: 935
Likes: 433
From: Dutchess county New York
ethanol
Zero difference after I don't remember how many years in terms of maintenance, longevity etc. I think 10% ethanol reduces fuel economy slightly - that E85 stuff gives us terrible mileage in flex-fuel vehicles - but it hasn't caused any other issues.
Race Director
Joined: May 2006
Posts: 18,692
Likes: 2,572
1972
Your profile says you have a 1972 which was designed for low lead/nolead to start with. You dont need anything.
Thread Starter
Melting Slicks
Joined: Aug 2004
Posts: 3,151
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From: Opelousas, Lousiana
CI 6-7 & 9 Veteran
Burning Brakes
Joined: Aug 2013
Posts: 1,071
Likes: 322
From: palm springs ca
Dom
Melting Slicks
Joined: Mar 2008
Posts: 2,666
Likes: 289
From: Spring Park MN
I agree with bashcraft, the only application I have ever seen much trouble with valve seat recession is in heavy applications like trucks or old RV's hauling trailers. Just not enough load and heat to cause it on Corvette's.
As far as ethanol goes, we have had ethanol gas up here in this part of the country for over 30 years. I have run it in everything I have owned in that time. Classic cars and motorcycles, lawn mowers, weed wackers, chainsaws, you name it. I store my cars over our long winters with the tank full and a can of seafoam in them. Never any problems in those 30 plus years.
Mike
As far as ethanol goes, we have had ethanol gas up here in this part of the country for over 30 years. I have run it in everything I have owned in that time. Classic cars and motorcycles, lawn mowers, weed wackers, chainsaws, you name it. I store my cars over our long winters with the tank full and a can of seafoam in them. Never any problems in those 30 plus years.
Mike
Race Director
Joined: May 2006
Posts: 18,692
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hardened seats
GM dropped the compression on all it's engines in 1971 in anticipation of low lead/nolead and started using hardened valve seats. You dont need a lead additive for your car.
Thread Starter
Melting Slicks
Joined: Aug 2004
Posts: 3,151
Likes: 294
From: Opelousas, Lousiana
CI 6-7 & 9 Veteran
Thank for all of the responses. From now on, I will just use premium unleaded in the Corvette, well after I finish off the lead substitute I still have. (so I won't have to dispose of it)
I did some other research and found that beginning in 1971, the valves on cars were hardened to allow for the use of unleaded fuel even though leaded gasoline was still available. This is good to know because it is a hassle using these additives.
I did some other research and found that beginning in 1971, the valves on cars were hardened to allow for the use of unleaded fuel even though leaded gasoline was still available. This is good to know because it is a hassle using these additives.
Burning Brakes
Joined: Aug 2013
Posts: 1,071
Likes: 322
From: palm springs ca
Well, I don't get to my valve machine much any more but I have yet to see a hardened seat or valve from the factory. Lets say 80's back.
True? maybe not , but the service manager (in 1971) told us when we complained that the factory was installing truck engines in cars because of the dished pistons that were used in trucks, "that's the new smog law".
Now they are talking about removing all the lead in Av-gas to clean up the air!! These are low HP, low compression, low RPM engines.
I guess it's who you talk to.
Dom
True? maybe not , but the service manager (in 1971) told us when we complained that the factory was installing truck engines in cars because of the dished pistons that were used in trucks, "that's the new smog law".
Now they are talking about removing all the lead in Av-gas to clean up the air!! These are low HP, low compression, low RPM engines.
I guess it's who you talk to.
Dom
Burning Brakes
Joined: Sep 2016
Posts: 935
Likes: 433
From: Dutchess county New York
Sea Foam
I don't normally use it (or anything else) as a regular additive but have been running it through the 'vette because it had been sitting a long time. It's helped noticeably.
