I have a used botom end b18a1 with a brand new rebuilt head because engine was smoking before with recent head so i thought it might just be the valve seals. the bottom end has 170,xxx kms on it and has perfect 180 lbs of compression right across. perfect oil pressure (around 70psi at around 50-60 mph). The only thing that i could think of doing is a leak down test. BTW the engine only really shows smoking around high idle start-up and the smoking starts to slow down after 2-3 mins. what could it be?

 

sounds like valve seals

 

yeah i changed the head once again, and when i did so I changed the valve seals but i guess it just took some time for them to seat properly. It doesnt smoke as much anymore