Lead additive necessary ?
 

My West Coast Cobra (circa 1984) has an FE 427 side oiler, I do around 1000miles /year do I need to have lead additive added during fill ups?
Tks,
Basque1(Lou)

What compression ratio does the car have? True lead additives were outlawed and can't be purchased. Most off the shelf formulas are legal alternatives that frankly aren't cost effective for street cruising. Paying an extra $10-15 a tank for a point or two of improvement can be done easily enough by sourcing a better grade at the pump.

If the motor is more than 11:1 compression, the choice of cam and it's timing would have a lot of influence over it's actual captured pressure. Basically, is the car pinging on what can be bought now? If it isn't, there's no problem to address. If it is, some new choices may need to be made.

Running on street gas and making power aren't mutually exclusive, but it is a matter of making the right choices and living with the reality of modern fuel. I'd be far more concerned about the fuel lines being incompatible with alcohol contaminants. It's a problem that is not going away. Compression can be addressed without machine work.

Another factor that plays is the valve seats. Do you have stainless steel valve seats that work well with no lead gas?

Well NYS still allows the sale of lead additives, they are available in places such as Autozone and Advance Auto parts. When it comes to gas I only use 93 octane plus Octane booster to 103.

I have never had a knock or ping since I have the car.I don't know if my valve seats are Stainless steel. I just changed the valve seals to cut down on the blue puff of smoke at 1st gear.

I have never used the lead additives in this car so I am just putting the question out since I was asked last week if I did or not. I am concerned thats all.
Tks for your input guys.
Sincerelyu
Basque1 (Lou)

lou,

those additives you see at the local parts stores really aren't lead additives. if you read the fine print they are substitutes, or octane boosters.
if your running a motor with factory iron heads, you should be concerned if the valve seats have been changed to accommodate for unleaded fuel.
you could cause valves to recess into the seats if the heads still retain the original seats.
running premium may be all you need for octane, but the long term effects of the valve seats is the issue.

The hardened valve seat is the most important part of living with no lead gas.

I honestly don't know if the seats are now hardened to accomodate unleaded fuel. I guess it is not economically worth it to use them. Tks
Lou

The only true, genuine lead fuel octane additive that I knew to be available was from Kemco. It was strictly a mail order product and was not legal for road use. I have most of a case of it still for my older cars and it's potent stuff. I want to wear heavy rubber gloves and a respirator when putting it in the tank. But I understand the owner died a few years ago and it's off the market now. I don't know of anything comparable.

yeah i used it too and there is nothing comparable...
i tried to get a chem. company to package some for me but the restrictions on it are so great that it is almost impossible to purchase raw material. i'm buying race fuel to jack up my pump gas now.

I have used Bardahl Instead of Lead Gold in a 65 Corvette for over 20 years

Tetra ethyl lead additives were eliminated a long time ago. At that time most engines were already being built with better valves and hardened seats in anticipation. Rebuilders began adding them to motors they were selling to avoid warranty issues, another reason the prices went up.

Unless you know you have a lead era motor from the early days that hasn't been retrofitted, you likely have the hardened seats. You can get the block casting numbers off the heads and then know what time period they were made in history and go from there.

Since pump gas is what most of us run, most crate motors are built with it in mind, and the complete lack of lead additives, too. These days, a high compression motor is rare - and running it problematic. They are mostly track motors and it's expected that knock will be a factor, the guy who selected the components knows to choose with care and the warranty he words with it.

It's part of why most motor rebuilders don't sell short blocks anymore, weekend racers were slapping on small chamber heads and blowing them up with uncontrolled preignition. So now, all the rest of us have no choice but to buy the motor long block or not at all. Read the warranty language on short blocks and see what little coverage you get. Read the crate motors compression and what cam is used - actual PSI isn't as much as we'd like to conform to the reality.

Has anybody ever used 100 low lead av gas? Crop dusters use this in piston engine planes.
I am sure this is not legal do on the street.

It should protect older engines with out hardened valve seats.

I add 1 gallon of 110 avgas for every 10 gallons of premium - runs a whole
lot better.

Some motor info would help
 

BAsque1 Lou If you are running aluminum heads and about 10.5 compression or less, stay with what you have and don't worry about additives. The best way to check the motor when running is a A/F meter in the exhaust and they used to sell a knocks meter for pinging. If the timing and the mixture are not at 13.8 or higher, you are in the safe zone. If you search around on goggle ther should be a couple of Sunoco gas stations that sell 100 octane unleaded. I don't think you can get a set of new heads with them having harded valve seats anyway. See if there are any small race tracks in the area and buy a couple of gallons of fuel. We used to use in the old days 130 AV gas. Hemi ran great but learned that AV gas didn't have the lubercation qualities that automobiles gas had. You did get great fires out the tail pipes and backfires. Bottom line, run the motor a little soft. Watch your total timing. You should be fine. IF you like that nasty smell, add a 2 gallons of race fuel. Rick L. I have FI system switch is more flexable for running gas from 89-93 depending on where you are at in this country. Also have an aluminum motor with heads to help stop knocks. Iron heads would be a different story. Rick

LPG has octane level above 100. So I'm strongly considering going that way with my new Cobra. All the crap they are putting in petrol is worse for the environment anyway.
You can run higher compression. It's cleaner. Less oil changes. Cleaner plugs. no moving parts. No fuel pumps. No blocked carby jets or injectors. So far I've run all my cars and tuned for pure gas with no problems. It's redibly avalailable in Ozz. And at half the price. And with the right mixer and aircleaner it looks like a carby.
JD

Take all that money you spend on additives and put it in the bank. Use fuel with an appropriate octane rating to avoid pinging under load. Drive and have fun. If your iron heads do not have hardened valve seats (at least on the exhaust side) and ss valves, by the time you suffer valve seat degradation, you will probably have suffered life degradation and won't care. Like I said, drive and have fun!

100% correct. All those additives are nothing more than, pardon the pun, snake oil. The only time I've ever seen valve seat recession without hardened seats was in a boat motor. Boats, motor homes and other engines that operate under heavy loads for long periods of time need hardened seats.

Thanks guys I will check around to get AV gas for next season. I will also verify the compression as well.
Cheers
Lou

Hi
I have been building FE motor's since about 62 or 63 for street and race. In the early 70's [72 or 73] we started installing hardened valve seat's in all of our build's so even if you have a c1 or c8 head etc. you could allready have the hardened seat's in it if it was buildt after the early 70's.
Even if you don't have the hardened seat's I have found out that you won't have any valve damage untill after 40,000 miles on the engine. I have pulled down engins that never had the hardened seat's with 55,000 miles and they had very little valve wear or seat wear but were ready for the hardened seat's.
As to the additive's I have never used them and don't recommend them for a well buildt motor. If you are worried about lube then if you add a small can of 2 cycle oil to each fill up you will be fine.
Greg

one added point is that if the motor has ever ran leaded fuel in it, the seats do retain some residual leading and don't recede, and i have to agree that its a 50k and up mileage issue, based on the mileage most of us drive a year, we won't see an issue in our lifetime....