I have a 1967 Mk 2, 2.4. I have asked various people what petrol to use. Some say super or Shell V is fine; others say I need to add lead. Can anyone provide a definitive answer? All answers gratefully received.

Hi Quentin, and welcome to the club.

Both my son and my late brother-in-law had problems with older cars which were built in the days when leaded petrol was the common anti-knock reason for existence. 

However, some older cars were converted to used what is now standard fuel.

I would be inclined to check whether the carburettor has been converted to use unleaded fuel.

Regards,

Peter.

Many thanks, Peter. So far as I know, the carburettor hasn't been converted. Does that mean I shouldn't use unleaded?

Hi Quentin,

I would check out a suitable additive for your car  until you find out for certain.  

Peter.

Will do; thanks again

The correct way is to modify the head and have hardened valve seats fitted, then you can use unleaded petrol without additives. I think the timing has to be adjusted as well.

For occasional use Castrol valve master or Castrol valve master + work well. (From a colleague who runs a 1300 mini)

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjQ15bPl5nQAhVLFMAKHXe-BRAQFghCMAA&url=http%3A%2F%2Fwww.opieoils.co.uk%2Fp-6519-castrol-valvemaster-plus-lead-replacement-octane-boost-petrol-additive.aspx&usg=AFQjCNGQQbSDEhZ5dSgfq6XChTKB6fIepg&sig2=OmkX0IQe8_0785PP8U2mEw

Edited November 8, 20169 yr by dattrike
Text added

That's helpful. Many thanks, David.

Dattrike is absolutely correct. To use modern unleaded fuel in your car would require the fitting of hardened valve stem seals. Retarding the timing or re-jetting the carb: may in some circumstances, on some cars work to some extent but hardened stem seals is the proper way to go.

P.S. Don't forget to have the head skimmed at the same time. 

hi Quentin

if you have any history with it have a look through it, as a lot of classics get converted when they have engine work

the valve seats need replacing, as its all ready running on unleaded the timing should of all ready been adjusted to suit

found this, have a look here

http://www.thevintagecar.co.uk/convertingvintagecarsunleadedpetrol.html

cheers

joe