Tapping noise that isnt tappets?

[Tubb]

got a tapping noise coming from my engine,
it sounds abit like tappets but only happens when the engine is under load, the engine is fine when idleing.
ive replaced the tappets and cam chain but its still the same.
anybody have any ideas of what else it could be?

[danny_p]

bottom end,  big ends ?

[mr self destruct]

Pinking? Is your timing ok?

[Tubb]

i re-did the timing last weekend so its not that.
how can i check the big ends/pinking?

[mr self destruct]

If your timing's ok the engine won't be pinking. 

[Thom89]

You can sometimes get a tapping noise from a blown exhaust gasket, particularly if its blowing where the manifold is bolted to the head...
Tom  

[Tubb]

hmmm, il have a look tomomrow, cheers

[DarnPB]

If your timing's ok the engine won't be pinking. 

Not exactly. Depends on how the mixture is set up. If it's running too lean, then pinking is possible. Also if you have a hotspot within the cylinder or the wrong heat range spark plugs, you may also get pinking.

[Wayne]

Piston slap maybe.

[Tubb]

its not the exhaust blowing as ive just checked that
i think the bottom end's on the way out as its just developed a new knocking noise