What is proper pressure in 2.2T head ?

[Albert]

Hello,

I have a drysump system form Repo and it has oil lines to:
- engine block
- turbo
- head

Before now I was having only one pressure meter in the block. But today I started measuring the pressure in the oil line in the head and it seems to be low.

On the engine block during cold start I have 7 bar
On the head during cold start I have 2 bar

What is the right pressure in the oil line in the head (hydraulic lifters) ?

Thank you for all your help