Ran rebuild lean - should I be worried?

[Mac-Porsche]

Hey All,

Just finished a full rebuild on a 1981 911sc and made a bit of a rookie error... I followed Wayne's book and ran the engine for ~20 minutes at higher rpms for the initial break-in.

Afterwards, I noticed the engine was very, very hot. The new SSI's I installed even bronzed in color a bit. This is my first rebuild - so wasn't sure if this was normal... However, the car's idle got rougher an wanted to stall after warm.

So after closer inspection, I noticed there was a brass line connecting to the back of the throttle body that was disconnected... My fear is that I ran this new rebuild pretty lean for the first 20 minutes and it has me stressing a bit now... Is it possible that I've done any significant damage in that time? I didn't hear any pinging or knocking, but still very worried... Am I over-reacting?

Any thoughts would be appreciated!

[stownsen914]

Running an engine for 20 minutes under no load is less likely to cause serious damage to your engine. Did you hear any backfiring or other signs that the engine was not running well? How was the oil temp during the run-in? If the engine is running dangerously lean, you would probably see it in oil temp.

You can pull a sparkplug to look for telltale signs of a lean running condition. Post a pic here and you'll get some opinions.

A new exhaust changing color might be normal. Post a pic of that too if you'd like.

[911 SLANT]

I was told for initial break in to drive car and put a load on motor to make rings seat. I did it like you on first rebuild ran it at high rpm and idle for 20 min. #5 cylinder rings never seated. Drove car for 150 miles and ring broke in #5 cylinder. Ended up doing another topend rebuild. Be careful on doing the way your doing. You dont want to glaze up cylinders. I'm not making that mistake again.I would drive car for break in.
Good luck!