Unleaded

[drmaloney]

I bought my S1 2 years ago (just before the factory closed). I have been using unleaded and adding the additives, but I am starting to worry about valves burning out. I have read the Haynes manual and the Steve Heath bible about the identification letter that should be on the block, but cannot find any trace of a letter. Does anyone know whether it is possible to tell from the engine number whether it has unleaded suitable cylinder heads?

[Le TVR]

The hardened unleaded versions are stamped in the centre of the cylinder head exhaust flange. It will either be D or E.

[drmaloney]

Hi
Those would be the letters I cannot make out or even find!