Had engine rebuilt and it has been running for around 8 hours. Two days ago I found out that very thin smoke start coming out from exhaust.

Here is the clip. https://streamable.com/tt2j1f

Going to take it to rotary shop soon but just wanted to know.

 

welcome to the board.

did the exhaust smell sweet-ish? check if the cooling system is over-pressurized.

 

Looks like blue smoke to me, should be oil related. Premixing it? Pcv system routed back to intake? Should check turbo inlet and see if it’s the pcv, should check after the turbo to see if it could be a bad turbo oil seal.

If you want peace of mind for the coolant seals, use a block tester and block tester fluid from the local auto parts shop.