Tappet noise conundrum

[Gfhug]

The engine had always sounded a bit tappety so have taken the opportunity of re-shimming the tappets but still have noise.
Fitted new long skirt cam followers and bought a couple of (good second hand) later camshafts which reports suggest should be quieter than the early cams even when they are properly shimmed.
After a couple of trial fittings and buying new shims got them all at 12 thou gap except no. one exhaust at 13 thou. As the later cams are supposed to be 12-14 thou inlet and exhaust felt all was good. Checked the camshaft timing and that is bang on. Didn't bother with the valve guide hold-down kit as all the guides were solid with no marks or anything to suggest they were loose. Everything torqued down correctly.
Sadly on start up still got a tappet sound, a fairly steady single note not multiple cylinders.
Frustration!
Took the covers off while the engine was still warm (run for 2-3 minutes) and checked the clearances (will do it again cold tomorrow) and most now showed 13 thou with two or three at 14, but nothing over.

Any thoughts?
Does a loose valve guide sound like a noisy tappet?
What does a loose/tight upper cam chain sound like?
I've heard suggestions to set these cams at 10-12 thou inlet and 12-14 outlet, any comments?

I did trial fit the cam followers to get cosy fit on each.

Thanks
Geoff

[mgcjag]

Hi Geoff.....A friend has been down this same route.....leave the gaps as per the manual....He is going to have the head of and new tapet guides and followers fitted.....I fitted the long skirt ones and it worked for me and the noise went...maybe your followers are a bit too loose..They should be a real snug fit be able to revolve and move up and down but not rock..... Steve

[Gfhug]

Thanks Steve, the followers all seemed like a good fit, some needing a positive push to get them down, certainly no rocking, but will check them again. Just don't fancy pulling the head, want to get her running so I can get the bit of welding needed to get her through the MOT. I had read your report of fitting the longer followers and was rather hoping for the same result as you. Will report when further checks done. Cheers Geoff

[christopher storey]

Geoff : I think you need to give it a good run before worrying, certainly longer than 2 or 3 minutes, to allow oil to get everywhere it should do. If the tick tick tick noise is still there then, then I should try and locate it with either a proper stethoscope or with a rubber tube with some sort of bellmouth attached to it. I doubt that a rhythmical speed related noise is chain thrash. There are other sources of such noises - the distributor is one if there is any mechanical contact between rotor and terminals, ditto the tacho drive if you have the generator type, and it might be worth running the engine in the dark and seeing if there is any spark leakage as this also can produce a surprisingly loud audible crack . Another thing which produces a similar noise is a pinhole type leak from an exhaust manifold gasket - a rubber tube in the ear is good for locating these

[ChrisC]

I have a single offending 'tapper' which is only apparent on cold start but disappears after 2-3 minutes. I don't actually drive the car anywhere until it stops but its no big deal as its not a long wait.

So I too would recommend letting it run for a while and then see if you still have an issue.

[Gfhug]

Thank you all for the various suggestions. Checked all cold clearances and came in at 12, with a couple of 13 thou, so all technically correct.
Following Christopher's comment I almost wondered if it was the new red rotor arm in the distributor. Changed it for the old one and I could have sworn the tapper had stopped. Then for it to return on the next start up. Grrr!!
A later engine so no tacho drive to cause the noise and when using a long steel rod as a stethoscope couldn't fix the noise to other than 'the engine'.
A longer drive is needed then to see if it'll go when properly hot, but that is going to have to wait for my welder to fit me in and then getting an MOT to be able to go driving.

Regards
Geoff