How long will she smoke?

[clarelaw]

I rebuilt my 81 911 SC about a year ago. It took me a few months to get the kinks out. Now she starts and runs fine. I drive the car maybe once or twice a week. She stays in the garage the rest of the time. I now have about 1700 miles on the rebuild.

The rebuild included new pistons (JE 9:8:1) barrels and rings. Other wise just a stock rebuild (ARP head studs and rod bolts, redone heads and values with new guides). However, I am running with the Oxy sensor off and a cat-by pass pipe.

When the car first starts up after sitting for 5 or so days, I still get blue smoke at the pipe. After she warms up everything runs fine and I don't get any smoke. If I drive it the next day, at start up there is no smoke.

Question is: Is this normal? Are my rings still breaking in? How long before she should not smoke at all on start up?

I thought maybe I had a broken ring, however if I did, wouldn't smoke all the time? Would the cat by-pass pipe cause the smoking at start up? I am tempted to just live with it, in that the car runs great and pulls hard and seems to have much more power than before the rebulild.

Any thoughs?

[john walker's workshop]

it's not a 911 if it doesn't smoke a tad on cold starts.

[clarelaw]

Thanks John - that is what I was hoping to hear. I think I'll run it for a few thousand more miles and see what happens.

[NevenM]

Hi

Sometimes they smoke and other times they don't I think it is where the oil pump stops and therefore how much oil seeps back into the sump, but if it goes away don't worry about it

HTH

Neven