21-09-2020, 09:37 AM
It's not a direct answer to your question Bob but in my humble opinion crank ringing, although better than nothing, will only find a total dud and is by no means a dependable test of durability. I don't think there is any completely fool-proof crack test method available to the impecunious amateur, but I generally use dye penetrant at home, and if nothing found I pay the man to do a magnaflux test for me (which is better at finding flaws just below the surface). And yes I would 'ring' it first to save wasting dye! It is also my experience that most flaws flagged up by dye penetrant are visible to the eye if you look carefully. Given the cost of an engine rebuild nowadays it seems a false economy not to use every available means to ensure a crank is sound.