Thanks Keith: a cautionary note:
I have done some work with torches and know , to heat plugs like these, one MUST heat the crank that surrounds them. Do you know that heating the crank journals does not soften the surface hardening of the journals? Re: Propane: The propane torch will heat steel to the "red" hot temperature if it is not too massive like the crank. It just takes time and steady application of the flame where you want it. It could take upwards of 10 minutes , but for the purpose of loosening the threads, it is safer than Oxy-acetylene which is several thousand degrees hotter and might change the metallurgic qualities of the steel in the crank. Cranks like these are VERY carefully cast and heat treated at the foundry that make them . It would be a shame to risk damaging the crank.
I have been driving an MG when the crank "let go" because I over stressed it with too high rpm . It was a rather sad affair which took a week of my summer to repair.
Just a thought...
Dave
