Lead substitute

[rileyimp]

Does anyone use lead aditive/substitute in their petrol??? I want to know if anyone really knows what it is. I read the back of several and it seems to me that all it is is kerosene. If in fact it is I would like someone to verify if possible. At $2.83 a pint for additive I can buy a gallon of kerosene and "do it myself".

 

[Dave Russell]

You can use whatever has the most attractive package. In my opinion, none of them are necessary. The truth is that you can run thousands of miles with no significant valve seat recession -- without any lead or additives. This is verified by a couple of very comprehensive test reports. I think the additive sellers are banking on the fact that there is very little valve damage in the first place & hoping you will think there is a benefit. It is a matter of "if it makes you happier do it."
D

 

[piman]

Hello Dave,

we came to unleaded petrol much later than you did in America.
The Federation of British Historic Vehicles Club commissioned a laboratory to do tests on unleaded fuel and also invited manufacturers to submit additives for testing. The results were significant head damage when run just on unleaded petrol (They only used one type of engine I believe, new Britsih Leyland 'A' type, Mini etc)
About six of the additives were proved to significantly improve the life of the engines and the manufacturer is allowed to carry the recommendation of the FBHVC on their product.
I personally use an additive in my Triumph, and have not had to do any appreciable valve adjustment in over 35,000 miles. I don't know what it would be like if I didn't use the additive but as there was a lot of headwork done to the engine I am happy to pay the little extra.
Certainly how the car is driven is a big factor but as I tend to drive it hard I will stick to the additive until there is significant wear then I will fit inserts.

Alec

 

[Dave Russell]

Hi Alec,
This topic has been argued endlessly. As I said, "It is a matter of "if it makes you happier do it.""
D

 

[Keoke]

[ QUOTE ]
Does anyone use lead aditive/substitute in their petrol??? I want to know if anyone really knows what it is. I read the back of several and it seems to me that all it is is kerosene. If in fact it is I would like someone to verify if possible. At $2.83 a pint for additive I can buy a gallon of kerosene and "do it myself".

[/ QUOTE ]

Well I think most of that stuff be Kerosene but save your money it won't save the valves. Most of this Valve recession nonsense can be attributed to "Irish Whispers" generated on the Isle of Mann. However, if you are concerned there is a product called "Real Lead" made for off road use only in controlled states. In your area of the woods it probably can be purchased and used. This product is actually what was formerly added to "Leaded Gasoline" and it will act as a lubricant for the valves.---Keoke


/ubbthreads/images/graemlins/savewave.gif

Hey Eric! you be listening too- /ubbthreads/images/graemlins/laugh.gif

 

[Dave Russell]

Since this thread is still going,

The theory is that without a lead coating on the valves & or seats, there are "microscopic" welds taking place between valves & seats which are broken & rewelded each time a valve opens & closes. This "could" cause erosion of the valves or seats.

A quote from a good source:
"It Is possible to fail exhaust valves in laboratory engines operated on dynamometers by running them --CONTINUOUSLY at very high speed and power output.-- Without the lead deposits present, the valves may wear or "recess" excessively into the softer seats. However, the conditions necessary to cause valve recession do not occur in normal driving, and can be attained only under highly unusual (and generally illegal) driving. Most people could not drive that way even if they wanted to."

Unless you are running on a race track, the main benefit of all this fuss is financial to the sellers of additives & to the machine shops that install hardened valve seats.
D

 

[piman]

Hello all,

in Britain anyway, the additives are either Manganese or Phosphorous(I think) based,not lead. To further expand on the U.K., the Fhbvc is a club, drawn from a spectrum of the British Classic, Vintage and Veteran car clubs whose aim is to protect and further the interests of those movements. It is formed of knowlegeable and qualified members and their test would certainly be suitable for 'typical' older vehicle use. I think,(and maybe I have the wrong idea?) that speeds in America are slower than Europe and steady speed cruising is the normal mode of driving. (Hence the reference to 'illegal'?)
Certainly the choice of only one type of engine is hardly good laboratory practice but to test a variety would have been prohibitive. They were brand new engines so would have no lead memory.
Dave, I agree with your viewpoint and it does make me happier to use it.

Alec

 

[piman]

Hello all,

another thought, In the U.K. again, aviation fuel for piston engines is still leaded, is that the same in America and if so why?
By the way we can still buy leaded petrol here but it's supply is limited and expensive.

Alec

 

[zblu]

So its a splash of kero now and again or some avgas!

 

[piman]

Hello Zblu,

I wouldn't add Kerosene, as far as I know that is just upmarket paraffin.

Alec

 

[Dave Russell]

[ QUOTE ]
Hello all,

another thought, In the U.K. again, aviation fuel for piston engines is still leaded, is that the same in America and if so why?
By the way we can still buy leaded petrol here but it's supply is limited and expensive.

Alec

[/ QUOTE ]
Hi Alec,
A partial quote from another web site --
---------------------------
"Currently, aviation gasoline (known as "avgas") for piston-engine aircraft contains four times more lead than was used in leaded automotive gasoline before it was banned from use in new cars in 1973. However, because the lead additive has been the most economical method for achieving 100-octane fuel, leaded avgas has remained the standard for high-performance piston-engine planes.

To avoid damaging the general aviation industry, the U.S. Environmental Protection Agency (EPA) agreed to permit the use of leaded avgas until an economic alternative was developed."
---------------------------
Yes, it is expensive. The USA is looking to alcohol based fuels as a solution, but still has far to go.
Regards,
D

 

[piman]

Hello Dave,

Thank you for that,I did wonder, so it is octane rating that is the criteria for the continuation of leaded fuel.

I know little about aircraft piston engines, but understand that they run constant speed most of the time and it is fairly slow (maximum torque runing?). I have no idea of specific power outputs/capacity but if a high octane is required I assume that it is fairly high?

Alec

 

[zblu]

115-130 over here

 

[wingsandwheels]

I use one of the lead substitutes tested by the British club; Redline, containing sodium. This is occasionally supplemented by the "100 Low Lead" avgas I drain from my Piper's sumps....a gallon a month or so. Does it do any good w/ the relatively esay driving I do??? don't know. I look at it as cheap insurance....and a convenient way to get rid of the sumped fuel.

The main issues with ruiining straight 100LL in a car are its low vapor pressure (relative to car gas, cold weather driveability issues), very high lead levels again relative to car gas and it is technically illegal. I know plenty of folks who run a mix though, mostly in high performance cars. Another potential issue w/ leaded fuel is that synthetic oils generally do not keep lead in suspension that well, do a search on Mobil AV1.

rgds, w