Just rebuilt top-end, should I still have startup smoke?
 

I just had the top end rebuilt on my 930, by a reputable shop. It is in the breakin period, and I'm getting a little smoke on cold startups (maybe slightly less than when I took it in with lousy leak down results and broken rings). I was expecting that after a fresh rebuild, there shouldn't be hardly any startup smoke. I can understand after 20-30k miles when rings are starting to leak, but right out the gate? Is it because it is in the break-in period? I'm hoping it gets better and not worse after break-in.

I thought all 911's puff at cold start after sitting.

Both of mine did. It was disappointing but it is the nature of the flat 6.

How many miles does the new engine have? Sure its not the turbo smoking?

Well, I can say the engine has less than 300 miles since rebuild. I'm not sure how many miles are on the turbo, as it is an upgraded k27 , unknown install date. Lets say the turbo probably has 30-40k miles. Regardless, my thinking is a turbo would smoke all the time, not just at startup.

good sign that oil is getting to the cylinders, bad sign if it's leaking past the valve guides. I would drive it hard for couple hundred more miles

Give it a few good "Italian tune ups" :)

At... "less than 300 miles since rebuild" I wouldn't worry just yet.

After 1,200 miles let's see how it is. I bet it will be a lot better but a puff of smoke at start up is normal for a 911/930.
Just a puff though.

Remember that the rings may take a few hundred miles to seat completely

Those were my thoughts. Here is a link that talks about oil in turbo chargers.

On the up side many of the issues have to do with turbo related issues rather than the turbo itself.

Common Turbocharger Problems

Also, the turbo charging forum here is a good place to search or post if you boil it down to the turbo.