Morris Minor Owners Club

I am asking for help trying to diagnose an engine noise on my Austin Ten, (yes, I know it not a Morris!) I would think the side valve engines are similar.
I have just had it bored out, new pistons & reground crank with new shells, it runs fine when on the move. But when on tick over at normal temperature, there is a big end type knock, I have taken compression readings, all are 145 psi, I have tried taking off the each of the plug leads in turn & no change to the noise. The noise disappears completely once above tick over
I don't think it is the timing chain, can only think it might be a valve or cam follower problem? Any ideas?

Can you identify where the noise is coming from, top, bottom, front, back?
Tappets? Loose? Rotating, Plenty of oil?
Had a similar problem on a rebuilt side valve, turned out to be an incorrectly fitted sump baffle plate being hit by the big end cap

Thank Mike, I can't really tell where the noise is coming from, I may buy a stethoscope..

Fault found now, cam spocket had loosened itself due to damaged threats on the locating bolts.

Thanks for letting us know, was it an engine out job?

Well done for sorting the noise problem
I was asked if I could sort out a similar noise in the front of the engine of this famous Morris 'The Triangle or Skinner Special' http://sucarb.co.uk/news/loud/ when it was resident in the village I live in.
I could not take the engine out as the car was books for Shelsley Walsh a couple of days later. The car is fitted with a side valve straight 8 Hudson engine with gear driven cam shaft, luckily I had the drawings of the front of the engine, so cut a hole in the timing cover (making sure that the saw teeth were covered in cutting grease to catch the swarf and a powerful vacuum cleaner was used as well), managed to extract the cam gear bolts locking wire in one piece then remove each bolt individually, cleaned the threads/bolts, replaced the bolts which were then loctited and torqued in place and turning the engine moved onto the next bolt. All bolts done the front of the car reassembled, changed the oil, started the engine and the noise had gone, the car competed at Shelsley Walsh with no cam gear noises. I think we caught it just in time because the car never had a problem with the timing gears after my repair.
If anyone from Burlen is reading this and wondered what the plugged hole in the timing gear cover was for - now you know