by 1972nail » Mon May 11, 2020 6:26 pm
For the OHV engine you don't need an octane boost substitute so you can save a bit there. As HC Fairley says you don't really have to be too strict about lead replacement as valve seat recession doesn't appear to be as big a problem as was originally made out, a bit like the Millenium Bug. Certainly consider getting the cylinder head fitted with hardened valve seats for peace of mind. My experience of running a Morris Minor since 1989 on the same basis as HC does with his car suggests that you should only consider conversion when the cylinder head needs to be rebuilt anyway. Our Minor has done in excess of 30K miles since leaded petrol became unavailable and it's cylinder head still doesn't need rebuilt.
Some people suggest using Super Unleaded in their engines and certainly, on the later post 74 OHV cars with the increased compression ratio, that is worth considering, but again your own trial will give you a good idea of what is best for you.
Editor of the VVOC Magazine ReVival
"When you have a Firenza like mine, who needs any Minis?" copyright David Maxwell 1979.