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Can you help me? What fuel additive/lead substitute should I use to run unleaded in my car? I have a 1967 435 H.P. JE-L71 427 cid. I no longer have access to leaded fuel for it. What is the best/safest type of fuel and or additive to use so that I can run the car without harm? Any help is greatly appreciated. Thank you. Steve.
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Re: HELP! What do I use for a lead substitute?
This topic has been somewhat covered in the archives. But in a nutshell, the lead additives (chemicals used to carry the lead in solution, I think) can be destructive to various parts of the fuel system including the carburetor and is generally not recommended.
I have recently used some of the lead substitute but I'm not sure what the long term effects are on the fuel system. My original 1970 LS-5 does run well with that but I also did a few things simultaneously that may have had simultaneous benefits. (1) I correctly set the timing, (2) I used GM's Top Engine Cleaner, (3)I added octane boost to the next tank of gas, (4) I've been using Sonoco 94 octane pump gas (without octane boost).
You may want to try altering your timing so that any ping goes away with a combination of some of the antidotes above. Another alternative is to have hardened exhaust valves installed and lower your compression ratio but seems a bit much for me if you can get away with the above.Tony -
Re: HELP! What do I use for a lead substitute?
This topic has been somewhat covered in the archives. But in a nutshell, the lead additives (chemicals used to carry the lead in solution, I think) can be destructive to various parts of the fuel system including the carburetor and is generally not recommended.
I have recently used some of the lead substitute but I'm not sure what the long term effects are on the fuel system. My original 1970 LS-5 does run well with that but I also did a few things simultaneously that may have had simultaneous benefits. (1) I correctly set the timing, (2) I used GM's Top Engine Cleaner, (3)I added octane boost to the next tank of gas, (4) I've been using Sonoco 94 octane pump gas (without octane boost).
You may want to try altering your timing so that any ping goes away with a combination of some of the antidotes above. Another alternative is to have hardened exhaust valves installed and lower your compression ratio but seems a bit much for me if you can get away with the above.TonyComment
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Re: HELP! What do I use for a lead substitute?
If lead additives are harmful to the fuel system, then how do you deal with the issue of not having lead in 70's vintage vehicles? Won't this cause problems with valves, etc if you don't use an a lead additive?
Jeff 68 BB convt ncrs 30292Comment
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Re: HELP! What do I use for a lead substitute?
If lead additives are harmful to the fuel system, then how do you deal with the issue of not having lead in 70's vintage vehicles? Won't this cause problems with valves, etc if you don't use an a lead additive?
Jeff 68 BB convt ncrs 30292Comment
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Re: HELP! What do I use for a lead substitute?
Jeff, I use a product made by Stewart Warner /Alemite CD-2 called Super Concentrated Lead substitute. It's sold in quart containers and one quart treats 320 gallons of gas.It also has a fuel system cleaner in it. I've run it in my 62+63 F.I. cars for years with no ill effects and I'm now putting it in my 67 427/390 motor. The best part is it only runs about 6 or 7 dollars per quart and the only problem is finding it all the time. I've bought it in K-Mart , PEP Boys etc. But when I do find it I buy a few bottles. It seems to work fine and doesn't cost an arm and a leg.Comment
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Re: HELP! What do I use for a lead substitute?
Jeff, I use a product made by Stewart Warner /Alemite CD-2 called Super Concentrated Lead substitute. It's sold in quart containers and one quart treats 320 gallons of gas.It also has a fuel system cleaner in it. I've run it in my 62+63 F.I. cars for years with no ill effects and I'm now putting it in my 67 427/390 motor. The best part is it only runs about 6 or 7 dollars per quart and the only problem is finding it all the time. I've bought it in K-Mart , PEP Boys etc. But when I do find it I buy a few bottles. It seems to work fine and doesn't cost an arm and a leg.Comment
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Re: HELP! What do I use for a lead substitute?
Lead has two different things it adds to the function of cars from the 60's, Increased octane, which reduces spark knock, or "Ping" and a coating effect which coats everything in the combuston stream with a light coating of lead compounds. This coating does two major things, one good and one not-so good. The good is that it coats the valves and provides a cushion between the valve and it's seat. The bad is that it coats sparkplugs and substantially reduces the useful life of a sparkplug-especially in a high compression engine. Whan automakers changed to unleaded gas in the early 70's, they recognized the potential effect of the loss of valve seat cushioning ang responded by using hardened seats in the heads. This effectively eliminated the problemof what is referred to as Valve seat Recission" which in layman's term's refers to an accellerated wearing of the seat area between the valve and cyl head. Many studies have been performed on this process, and the concensus appears to be that it only is a significant problem on engines operated at high loads for lengthy periods of time. In other words, in a collector Corvette, even one driven regularly in normal driving it is not a problem. The problem normally is seen in industrial equipment, farm tractors and the like. Even so, if you are the cautous type (like me) when I have an engine rebuilt, I have the machine shop install aftermarket hardened seats on the exhaust side of the head. This has the additional advantage of reversing the effect of several valve jobs which may have been previously done and lifting the valve seat back to it's original location, thus ever so slightly improving brearhing. This is especially important if you are trying to use a set of '461-X heads rescued from a life among a group of racers! With this process, you can rest easy that valve seat problems have been eliminated (overkilled is a better term) from your life. If valve seat wear is overblown, then what about Octane? The first thing to remember here is that the octane numbers you see today are far different from "the old days" at least partially because the Government mandated a change in the way octane numbers are advertised. Without going into details, this knocked about 4 points off the "advertised" number of a number of high-octane fuels. The result of this is the with since most Corvette engines running at "advertised" compression of 11.0 to 1 actuallu checking out at about 10.25 or so, high-test pump gas is generally suitable for all normal use. I road toured my '62 FI car last summer ( actual CR of 10.75) without problem. If you want an occasional dragstrip bash, Between 25% and 50% racing gas (leaded) mixed with good pump unleaded will give you all the octane you need. I hope this helps.Comment
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Re: HELP! What do I use for a lead substitute?
Lead has two different things it adds to the function of cars from the 60's, Increased octane, which reduces spark knock, or "Ping" and a coating effect which coats everything in the combuston stream with a light coating of lead compounds. This coating does two major things, one good and one not-so good. The good is that it coats the valves and provides a cushion between the valve and it's seat. The bad is that it coats sparkplugs and substantially reduces the useful life of a sparkplug-especially in a high compression engine. Whan automakers changed to unleaded gas in the early 70's, they recognized the potential effect of the loss of valve seat cushioning ang responded by using hardened seats in the heads. This effectively eliminated the problemof what is referred to as Valve seat Recission" which in layman's term's refers to an accellerated wearing of the seat area between the valve and cyl head. Many studies have been performed on this process, and the concensus appears to be that it only is a significant problem on engines operated at high loads for lengthy periods of time. In other words, in a collector Corvette, even one driven regularly in normal driving it is not a problem. The problem normally is seen in industrial equipment, farm tractors and the like. Even so, if you are the cautous type (like me) when I have an engine rebuilt, I have the machine shop install aftermarket hardened seats on the exhaust side of the head. This has the additional advantage of reversing the effect of several valve jobs which may have been previously done and lifting the valve seat back to it's original location, thus ever so slightly improving brearhing. This is especially important if you are trying to use a set of '461-X heads rescued from a life among a group of racers! With this process, you can rest easy that valve seat problems have been eliminated (overkilled is a better term) from your life. If valve seat wear is overblown, then what about Octane? The first thing to remember here is that the octane numbers you see today are far different from "the old days" at least partially because the Government mandated a change in the way octane numbers are advertised. Without going into details, this knocked about 4 points off the "advertised" number of a number of high-octane fuels. The result of this is the with since most Corvette engines running at "advertised" compression of 11.0 to 1 actuallu checking out at about 10.25 or so, high-test pump gas is generally suitable for all normal use. I road toured my '62 FI car last summer ( actual CR of 10.75) without problem. If you want an occasional dragstrip bash, Between 25% and 50% racing gas (leaded) mixed with good pump unleaded will give you all the octane you need. I hope this helps.Comment
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Re: HELP! What do I use for a lead substitute?
Rich----
I recommend the Stewart-Warner Alemite product, too. In most cases, as Bill Clupper described, valve seat recission is not really a problem for vehicles with non-hardened valve seats unless they are operated at high loads for extended periods of time. However, just to be on the safe side(before I had hardened seats installed), I used a lead substitute and the above-referenced is what I always used. This is for two reasons.
First, this product contains, as its active ingredient, "Powershield" manufactured by the Lubrizol Corporation. I consider this to be the best of the 2 "active ingedients" used in lead susbstitutes. It can also be found in many other brand name products, but......
Second, this product is concentrated unlike the other products on the market that contain "Powershield". So, as you say, one bottle treats up to 320 gallons of gas, although I recommend using it at "double dose". This means that you don't have to carry a box full of individual bottles with you on a long trip. Just one or two bottles of Stwart-Warner Alemite and you're all set.In Appreciation of John HinckleyComment
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Re: HELP! What do I use for a lead substitute?
Rich----
I recommend the Stewart-Warner Alemite product, too. In most cases, as Bill Clupper described, valve seat recission is not really a problem for vehicles with non-hardened valve seats unless they are operated at high loads for extended periods of time. However, just to be on the safe side(before I had hardened seats installed), I used a lead substitute and the above-referenced is what I always used. This is for two reasons.
First, this product contains, as its active ingredient, "Powershield" manufactured by the Lubrizol Corporation. I consider this to be the best of the 2 "active ingedients" used in lead susbstitutes. It can also be found in many other brand name products, but......
Second, this product is concentrated unlike the other products on the market that contain "Powershield". So, as you say, one bottle treats up to 320 gallons of gas, although I recommend using it at "double dose". This means that you don't have to carry a box full of individual bottles with you on a long trip. Just one or two bottles of Stwart-Warner Alemite and you're all set.In Appreciation of John HinckleyComment
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