New 911 rebuild smoking

[dlr10543]

Good morning. I just had my 88 3.2 911's engine rebuilt by a reputable independent Porsche-only shop in my area. When I got the car back, I noticed two issues. The first was oil leaking on the driver's side of the engine. To their credit the shop willingly stated they would correct that. The second issue was that on start-up I get 30-seconds or so of smoke, which eventually clears up. No smoke thereafter. until the next cold start. I can see the oil leak being relatively easy to fix, but the shop says the smoke is common while the rings are "seating". My question to the gurus on this forum is: Is the shop correct on the rings seating and, if so, how long does this take? I have about 200 miles on the engine since the rebuild. I am worried about this because the "fix" for this may mean pulling the engine and tearing it down again. I anticipate the shop being reluctant to do this. Help?
Dennis

[proporsche]

i am surprised that the shop did not break the engine in for you at least they should give an instruction how to break it in..i usually do at least 300-400 km before i would give the rebuild engine to client.And yes the rings needs to be broken in......Do you know they should be doing 1000 miles service after for free? adjusting the valve recheck the heads rocker shafts and e.t.c.

Ivan

[proporsche]

..

[dlr10543]

Thank you Ivan, very helpful.

[proporsche]

the best you can do is go for long drive non stop...use the gears to slow the car -like 4th and 3rd..stay away from traffic and at least 100 - 150 miles at a time....
i am sure someone will pitch in another way for the rings ..i do it like this but with more miles --i have the time;-))))
After you do 1000 miles they should change the oil and filter as well the other stuff..

[proporsche]

....

[Trackrash]

It took something like 700 miles to seat my rings on my motor.

Did the shop use new cylinders, re-ring your old ones, or have them re-plated?
New pistons?

Also a high oil level can lead to smoking on startup.

I would drive in a spirited manner, without redlining the motor. Let the engine slow down the car.

[Bill Douglas]

Originally Posted by Trackrash

I would drive in a spirited manner, without redlining the motor. Let the engine slow down the car.

Yep, it's now or never to get the rings to bed in - your once chance. If the car is driven too mildly they will never bed in.

And as mentioned, deceleration is important.

[andreww]

I haven't built a 911 engine but many Alfas, VWs, MGs, Fiats, mostly with Hastings rings, a few others. Have not had this experience with smoking from new. Breaking in should happen immediately upon ensuring engine is running fine, no leaks, timing right, etc. Go out and do it immediately based on ring maker's recommendation.
What oil you using? Non-synthetic break-in oil is generally recommended but I have also used a normal good 20-50 with good results. Compressions are good from the outset, oil use settles down quickly/immediately.
Andrew

[Rosco_NZ]

Nikasil cylinder engines can take a while to break in .. but if it’s still smoking at 1000 miles, rings may never bed in. Make sure no synthetic oil in it .. and lean on it, without red line and use lots of engine braking .. good luck.

[47silver]

we used brad penn break in oil.

[rokemester]

One would think the engine rebuilder would provide knowledgeable guidance for proper break-in.

[Nick Triesch]

Make sure fuel injectors are good. I had the same problem, new expensive injectors did the trick.

[dannobee]

Verify that the engine oil level is correct with the engine at operating temperature. Too high and the oil level in the crankcase will go above the level of the cylinders after it sits awhile. Then the oil will seep past the rings, causing smoke on startup.

[dlr10543]

Thanks to all for the thoughts. Took it to the shop today and the mechanic says it's a rocker arm. Can this be replaced without pulling the engine?

[wazzz]

Waiting for Ivan or others to confirm, but I think yes.

[proporsche]

wait a minute? the mechanic said the car is smoking due to the rocker arm??
or why he said it? I thought we are talking about engine smoking?
Ivan

[dannobee]

I guess we should have first asked if the smoke was coming OUT of the tailpipe, or from a more general area under the engine.

A rocker arm shaft could leak oil onto the exhaust, causing smoke on startup, but not out the tailpipe.

[proporsche]

the shops has fixes the oil leak,the OP said....

Ivan

[dlr10543]

ProPorsche - the engine smokes on start up and leaks oil. The shop stated that the rocker shaft was the source of the oil leak. Thanks for your comments.