Thanks for that, but next time a little less heavy on the technical details and space-age terminology.

Hi, I've just bought a Series 3 109 pickup. It was running fine when I got it, but two days later the head gasket went (big chunk blown out the back of number 4). I've changed the gasket and there is still white smoke billowing out of the exhaust. Assuming the head was warped, I took it...