Hi Guys
Here is I think another reason for engine rattle, it's only a theory maybe others have proved it. I recently purchased a new set of cam followers 'Made in England' but not the very expensive ones. I found that the center exhaust followers would rotate much more than original genuine ones and when I measured them they were nearly - 0.010" across the flats, down on the original ones. I have returned them and I am using a mixture of new and used genuine ones, I also am using the best pin I have and I found a variation of 0.002" between pins.
The followers will naturally try to turn when the engine runs and also affect its inlet partner this is potentially quite a clatter and will give the twisted wear pattern seen sometmes, the singles have a much better arrangement.
Any thoughts
Chris