Leaded or additive?
Discussion
Personally I think a lot more was made of this than happened in real life.
Run the car on unleaded and if you ever get valve seat recession then sort it when you re-fresh the heads.
You won't do much damage if you are only doing a low annual mileage!
No point in fixing something that isn't broken!
N.
Run the car on unleaded and if you ever get valve seat recession then sort it when you re-fresh the heads.
You won't do much damage if you are only doing a low annual mileage!
No point in fixing something that isn't broken!
N.
Have a good read on web about unleaded engines and classics, and especially the 'lead memory' effect.
Although there was a lot of gnashing of teeth, truth is many classics are happily running around with no additives and no problems.
The 'lead memory' effect is that after an engine has run a long time on the old leaded gas, the lead tends to sink into the micropores in the cylinder head, which helps protect the valves.
It also depends how you drive and the actual engine design. Heavy acceleration/load drives up the valve temps, which ups the chances of valve recession, but it all depends....
N.B. I've driven around in My wedge (2.8V6) unconverted for many years and had no issues, after fiddling around to get ignition timing right....but see the wedge blog where ZigaZaga supercharged his wedge and had immediate valve problems, probably down to higher temps....
Although there was a lot of gnashing of teeth, truth is many classics are happily running around with no additives and no problems.
The 'lead memory' effect is that after an engine has run a long time on the old leaded gas, the lead tends to sink into the micropores in the cylinder head, which helps protect the valves.
It also depends how you drive and the actual engine design. Heavy acceleration/load drives up the valve temps, which ups the chances of valve recession, but it all depends....
N.B. I've driven around in My wedge (2.8V6) unconverted for many years and had no issues, after fiddling around to get ignition timing right....but see the wedge blog where ZigaZaga supercharged his wedge and had immediate valve problems, probably down to higher temps....
I've used Castrol Valvemaster Plus for the last 5 years. I don't know if it's helped to protect the valves or not but I do drive hard, so for a small investment it seems to worthwhile. It also boosts the octane which I think it possibly more important in reducing pinking which is definite potential for serious damage. £12 for 250 litres of fuel.
I believe it is not just the valves you have to worry about but the ethanol content of modern fuels.
Ethanol is very corrosive to many of the materials that were commonly used in fuel system of older vehicles like ours.
The solvents in Ethanol will attack any component made with plastic or rubber compounds e.g fuel hoses that it comes into contact with, although many modern cars have plastic petrol tanks so that confuses me a bit. Components made from brass, copper and aluminum can become corroded over time if they are not given proper surface treatments.
Also, I was advised by a Ford V8 specialist engine builder that modern fuel only has a life of about 8 weeks before it can start to give problems, especially for example optimax so I should use a fuel stabiliser if not using the car for any length of time.
I know a lot of vintage car owners have had a lot of problems with modern fuel, vaporisation, hotter than normal running etc. I use Tetraboost in a 1935 car I have, don't know if it has done any good, but it doesn't appear to have done any harm. The car only does around 1000 miles a year but I have had it 16 years. I seem to remember practical classics doing a test many years ago on a number of products, which proved valve seat recession did indeed occur without an additive of some sort.
Regards
Nick
Ethanol is very corrosive to many of the materials that were commonly used in fuel system of older vehicles like ours.
The solvents in Ethanol will attack any component made with plastic or rubber compounds e.g fuel hoses that it comes into contact with, although many modern cars have plastic petrol tanks so that confuses me a bit. Components made from brass, copper and aluminum can become corroded over time if they are not given proper surface treatments.
Also, I was advised by a Ford V8 specialist engine builder that modern fuel only has a life of about 8 weeks before it can start to give problems, especially for example optimax so I should use a fuel stabiliser if not using the car for any length of time.
I know a lot of vintage car owners have had a lot of problems with modern fuel, vaporisation, hotter than normal running etc. I use Tetraboost in a 1935 car I have, don't know if it has done any good, but it doesn't appear to have done any harm. The car only does around 1000 miles a year but I have had it 16 years. I seem to remember practical classics doing a test many years ago on a number of products, which proved valve seat recession did indeed occur without an additive of some sort.
Regards
Nick
Edited by Nick Brough on Thursday 8th September 06:29
Just a replay to this topic, I am very active in the classic cars and it is no secret that the ethanol is giving a lot of problems, we always give customers the advice to use premium fuel 91 octane, that is the highest we can get here in Edmonton Canada. I have never replaced so many fuel tanks, lines, hoses, etc the last two years.
Even with a stabilizer the fuel goes off, we recommend now to run the tank as empty as possible and the same for the rest of the fuel system.
Even with a stabilizer the fuel goes off, we recommend now to run the tank as empty as possible and the same for the rest of the fuel system.
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