Forged pistons and cold mornings

[Pyrotechnic]

I have Mahle forged pistons. When it's cold out, I get some rough running and some oil smoke out the exhaust on start up for about 2 - 3 minutes. Not excessive smoke, but there is some. During this time, it's very unwilling to rev and basically undrivable. It feels rough, but it stays running just fine. After this time passes, you can hear and feel the motor start to smooth out and the idle speed starts to increase and the oil smoke stops. At this point it's ready to drive. No smoke at any other times other than a cold start on a cold morning. Motor runs excellent and makes great power. On a cold start on a hot day, I do not have this issue at all.

What it seems like is the rings don't seal completely till the piston heats up and swells. Anyone else ever experience this ? Just making sure this is normal behavior for forged pistons.

I also have an RPM Air Gap intake which I suspect doesn't help the cause, being that fuel will tend to puddle rather than atomize in the cold. One thing I did was put a stock air cleaner on with the hot air tube against a header tube and it does seem to reduce my warm up time a little. The plan is to eventually make an enclosure for my open element air cleaner that will give maximum flow but allow for the hot air tube on startup.