Annoying knock from camshaft front pulley area

[Charles P]

I find it easier to do all this with the engine sat on its bellhousing vertically on the bench.

Have fun.

Doing it on your back, inside the crankcase, trying to keep the rollers in place and wishing for a third hand, is undoubtedly possible but not advisable if anyone within 100 yards might be affected by the resultant extremely flowery language. 
I reckon it would be quicker to remove the engine, and possibly mentally less damaging.

c