[Healeys] Undoing the crank nut

[Ronald A. Fine]

One old trick which read about and used recently is to remove the spark plugs and take a long piece of rope and feed it into one of the cylinders that is moving up on its compression stroke, filling the cylinder.  Make sure you have the correct cylinder because you don't want either valve to be open.  Be sure to keep a tail out so you can remove it later.  Then gently rotate the crank until that cylinder rises to compress the rope. It will eventually stop and you can remove the nut.
It worked for me.
Ron