DonaldBuswell

The Lower crankcase section is matched to the Block, I want to know if this matching consists of machining each segment to one another? The S4 engine I recently acquired has this lower section with a crack in it and a small section of surrounding material missing. The person I got the engine from discovered this crack at the time I did and was professionally embarrassed as I have also been in such situations myself so I find no fault on his part. I asked him, and called a well-known 928 parts supplier and both of them did not know if my original S4 lower section would be a perfect union to this new S4 engine. Asking questions that stump the experts always brings a smile to my face!

Coming home I check my original S4 motor and there are matching numbers on each segment, I checked my 16v motor and similar matching markings are present. So, perhaps this code is a date or code number corresponding to manufacture date or other identifying markings? But, if each lower crank shell is matched to the block with machining - am I fooked on this 'deal', meaning I go get another motor someplace?

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polecat702

The girdle is mated to the block, it's a machined fit, I don't think you can just swap them, Don.

DonaldBuswell

Hey Polecat! I spoke with Jake Myers, a former student of Greg Brown and he confirmed what I knew deep-down, these are mated and matched parts. So...I will get the front section welded up.

Kevin in Atlanta

I know from personal experience the lower section can be welded. But, before I would start down that route, I'd split the block and run it through your parts cleaning machine, look for evidence of a crack on the inside of the lower section.