noise from fresh built short block

[LeonL]

I have just completed replacing the built short block. Currently I am breaking it in with first batch of regular 5w30 oil. Warming up for about 25 minutes. I have flushed out the first batch of oil, Refilled with a new batch of 5w30 and new filter. Car crank and idle fine, but engine sounds "rough" (sounds like knocking) when it first crank. Then is will get softer after 5-10 minutes warm up. Could it be because it is a freah short block? Oil is too light 5w30, maybe use thicker oil 10w40? Pistons, rods, chain, tensioner are all new. Is the noise normal?
Tanks in advance.

[Sileighty_85]

No, knocking is not normal, Some tapping from the lifters will be normal until oil puressure is restored if it sat for along time and or lifters need to be bleed.

[LeonL]

Short block is freshly built. Head was working before I took it off to be place on the new block. My "old" stock engine is pretty "quite" and smooth.