Advance ignition..

[pete376403]

Also BMC A series engines had a crapola combustion chamber design (sort of flattened out heart shape) which included a a little peak of metal sticking out between the valves to glow red hot and act as an ignitor. First rule of tuning a Mini was to remove the peak, which had no effect of compression but had a huge effect on keeping piston crowns out of the gearbox.

[Brian d marge]

well here they are , these are those pesky blighters that cause the damage in your wisco

Stephen