Thanks for the input of options and this is what makes car repair forums great. I lack the knowledge of what can be done to the M117 aluminum head and know there are guys here with the needed answer. I believe in taking time to make a plan of action, asking other for their valuable input, and then work the plan.
The head seems to have been removed before my take-off; bolts and gasket differences. The head was not stuck to the engine. I was only warned about the many problems these M117 engines can give when one removes or breaks the factory seal of engine to head.
My background with major engine repair/machine work is only with US pushrod engines. Around 1980, I moved to the Datsun 240/260/280/300 overhead cam engines. Then in 1985, I bought an Alfa Romeo spider and loved their design/simplicity. I never needed to perform deep engine maintenance to either of those two engine families. Due to the Datsun’s cost, horsepower, handling, and available high performance part selection, I chose them as my primary projects. I not scared of the M117 and look forward to learning them with my daughter (who must work on the 500SL to drive it
).
So far, it seems the best course of action is the machine shop repairing the valve seat. My fear is it may be beyond machine shops efforts.
The manual states to test the valve adjuster with the butt end of hammer for recoil. Is there any other test? Is the original valve seat of the same cast material as the head or is it’s origin of different material/part that is pressed into place? My plan is to clean-up the head tomorrow and really inspect/assist the situation. I may have jumped to the conclusion of bad craftsmanship. Due to the budge of aluminum mushroomed material on the outer rim of valve seat, I assumed that the seat was reamed with tool as a patch. That would be a ghastly remedy to a head that cost as much as entire engines of other makes.
Man, these engines are costly!!!