Rb25det top end noise after new headgasket

[Rb25detgqpatrol]

Rb25det top end noise after new headgasket

Hi everyone I need some help 

I have a Gq patrol with a rb25det 

I have just changed my head gasket as my old one blew n was overheating ,     

So I replaced my head headgasket , new alloy radiator, and new 450hp turbo with 3"dump and stainless exhaust 

On start up after putting it all back together it has a bad tap in my top end sounds like a tappet noise but doesn't go away I let warm.up but still there and doesn't doesn't wanna rev properly either now I set base timing tic, then to its mark and set intake and exhaust cams to there mark also

 

 

If anyone has ideas that would help heaps thanks in advance ,,,,,,,,

[GeeDog]

Probably unrelated, but we built an RB25/30 recently. Put it all back in the car (R33 Skyline), and have also had a tapping noise, seemingly from the top end.

Today teh alternator died, and we replaced with another used one. Started the engine & the "lifter" noise was compeltely gone. Did several track sessions & it hasn't come back. Glad we didn't pull the rocker covers - everyone who heard it was convinced it was a lifter. Ours was revving fine though.

[KiwiRS4T]

Try a compression test. Do you know why the headgasket let go? Try pulling the coil leads one at  a time to see if you can isolate the noise to one cylinder or use a big screwdriver or stethoscope to see if you can trace the noise. Got a boost leak somewhere?

[Rb25detgqpatrol]

ah cool cheers manged 2 make it some what go away timing jumped a tooth , tenison was gone so put a new one n re set , its still there but not fully gone away i took it for a drive in it has a lot of power still doesnt struggle to to hit 14psi now so alolifters art better but not fully gone ,,,,,, i got told the lifters are common to go 

[Ben C34]

What kind of bullshit occurred for the timing to jump a tooth?