Break-In, and Enter-In...
My local independent MB garage suggests a simple non-detregent oil for the first 1000 miles, then you could change to synthetic if you choose. That will be sufficient for "Break-In".
The service manager at my local MB dealer says that they used to have a 1000 mile initial "break-in" period after which they would do a valve adjustment and 1st oil change.
He said he has had no information from the factory about the new engines being specially prepared, or "broken in" at all. These new cars come from the factory with Mobil 1 in the crankcase, and do not get their first scheduled oil change for 10,000 miles. He added that they recently got a service bulletin from Mercedes directing them to only use Mobil 1 on all cars that come in for service from now on...
His thoughts on breaking in your rebuild were the same at the independent garage, and added that a rebuild needed to be treated as it would have been originally, because the rebuild wouldn't be representative of the closer tolerances that the newer engines are being built to.
[Edited by longston on 01-31-2001 at 12:33 PM]
"We drive into the future using only our rearview mirror."
- Marshall McLuhan -
Northern California Wine Country...
"Turbos whistle, grapes wine..."