I've put the engine back together now and it's back up and running. As expected really, it's exactly the same as before, tapping as soon as it gets warm.

I'm a bit peeved off that I didn't manage to get to the bottom of the problem, just stripping the engine down to the camshaft and re-assembling probably took me in excess of 40 hours work.

I've had a long chat with Chris from RPI and I'm now resigned to the fact that it's probably a loose liner. He explained that any other problem, be it a worn camshaft or faulty lifter would manifest itself when cold, not hot!

So, as soon as funds allow I'll be putting a short coscast block in it. While I'm at it I will upgrade it to a 4.6 with a Piper cam so that I actually get some benefit out of a bad situation.

Thanks to everyone who has had some input in this thread.

They conclude it needs a new engine based on a phone call??!!!

Pop over to the V8 forum- v8forum.co.uk there are real RV8 boffs over there!

Even if it were that (which I still doubt) I'd be wanting a top hatted block from v8d, turners etc

Did you repalce the rockers? I ahve the same issue but I have read there is a steel insert at the pushrod end that can become loose when hot, so it won't be aparent when cold