I am wondering the thread size of the plugs. I think it must be a hair under 7/8”.
For a stock head, the spark plug size is 1/2 inch pipe thread.
Thanks. I need a little education on pipes and threads. So the size of the pipe is determined by the inside measurement which makes sense. My old plug seems to allow a die to thread loosely with 7/8” and 14 threads per inch. I have a 3/4” but the number of threads is16 per inch which seems to be too many. It probably should be 14 as well. I will take it over to a neighbour to see what dies he has.
That’s quite interesting. In order to lift the head off the block, it’s recommended to thread a pipe into the spark plug hole. The plug threads are tapered. I assume the threads in the head are not, otherwise they could be damaged. Is that correct?
Thanks for this. It is much appreciated.
The T cylinder head spark plug holes are 1/2” pipe thread , same as the spark plugs. For assisting lift of that iron cylinder head off the block a used take apart spark plug can be fitted by bolting in a lift eye, place two and makes easy lifting and replacing of the head. You could use a straight piece of 1/2 threaded pipe, but grasping a round pipe makes lift more interesting.
Thanks. I do have a set of take apart plugs. I will give it a go come spring.