Phil, sorry to read that plug has failed, I`m guessing perforated as the result of corrosion as opposed to pushed out by frost. If corrosion I suspect all are best replaced at the same time, which is hopefully some consolation for if it had been one of the others, you would be left wondering if/when the one behind the flywheel might fail...
John.... David Vizard, that is a name from the past, I bought his book in the early 70`s Tuning for Speed, having seen it advertised in Car and Car Conversions magazine at the time..I had just roughly re-built what was to be my first car, a 59 MK1 Austin Healy (frogeye) Sprite, over carbd over cam`d and a steep learning curve having got it wrong in terms of balanced modification...Duh..!
