Clattering at 4000rpm

[lear]

Sorry for all the questions; just two days in to ownership and it is a little different to my old Chimaera! What is indicated by a loud clattering noise from the valvetrain (I think) above 4000 rpm? It is a very noticeable metallic thrashing/clattering sound like a box of nails being shaken (sort of). It kicks in literally at 4000 rpm; up to that level it sounds fine. I recall my Chimaera always sounding quite clattery so I'm not sure if this is at all normal or not. Since it is a track car I need it to be able to run at fairly high rpm and at the moment would be afraid to do so. Thank you very much!

[Campbell]

Sounds like your oil pressure is droppin off and the tappets cant keep up.
I would look at the oil pressure your getting from cold and hot while the engine is ticking over.

[Wedg1e]

Could be a stuck lifter or a lobe worn off the camshaft...

[wooly350i]

My old engine did that about 3000 revs,i believe it was pinking due to running lean. Only did it in warm weather,cooler temps it seemed fine.