Smoking and Dispondent

stevef · stevef's Garage

I have just recently finished my 69 2.0L top end rebuild. Got the moter back in the car and after about 1 hour of run-in driving I'm getting quite a bit of smoke. Is this normal? It's blue/white stuff so I know it's oil. I put in new rings, had the valves reground, new guides and seals. Cylinders and pistons were in spec. I can't think of what might be wrong. If this is to be expected I might be able to sleep at night a bit beter. Any thoughts anyone?

Thomas Owen · 05-20-2002, 06:05 AM

If the engine was consuming a lot of oil before the rebuild you may have some build-up in the exhaust that is just being burned away. That would be good. If, on the other hand, your rings are not seating then you have a different problem altogether. How did you coat the walls of the cylinders on assembly? You should never use more than a drop of oil spread evenly around the cylinder or seating problems can occur.
You may want to run it for longer to see what happens.
Good luck

Superman · 05-20-2002, 06:56 AM

The smoking is not unusual. I believe the total wear, both ovality and taper, of my cylinders was no more than .04mm, which is only about 1.5 thousanths of an inch, and many predicted my engine would smoke. Bruce Anderson did, I think, and suggested I get rough with it right away, don't let it idle, he said.

So, use the throttle and see if you can get the rings to seat. If not, it is apparently not unusual for rebuilt Porsche engines to smoke if the cylinders are not replaced.

stevef · stevef's Garage

Thomas, The engine did smoke before I rebuilt it and I did use quite a bit of oil during the build up, So I guess I could be burning off some build up

Superman, I took part in that long debate we had on new rings. I eventually went with new rings as my cylinders were within half a thousanths of an inch ovality.

Took the car out today for a run and it did appear to have diminished a little so I'm feeling a little more comfortable. In fact my wife remarked when I drove back in the drive way that I wasn't "laying a smoke screen like a WW2 destroyer". I'll keep "using the throttle" Checked the oil level at idle and it's just under a half full so I know it's not over full.
Thanks