Gage

Trying to identify the engine type in an 82 ROW 928 S and hoping the brain collective here can help fill in some missing pieces of info. The engine has no stamping on the ID pad. Does not appear to have been ground off but rather has a cast looking surface. I assume the engine to be a factory or dealer replacement; does anyone have experience with other unidentified blocks? The car had it's CIS "S" induction in tact other than the manifold tubes (which are smaller diameter than the typical S tubes), an aluminum adjustable fuel distributor and a frequency valve (which I expect was part of the federalization process). The throttle body and air guide are the larger S type and the cams are correct for an S. The chassis was German delivered and automatic so the original engine designation would have been M28/12.

Ad0911

According to the cylinderhead 928.104.356.1R my guess is it is a M28/20 engine (4.7 US/Canada)

Mark Anderson

I agree 83-84 4.7

Gage

Thank you for the responses. Any thoughts on the block ID pad being blank or info that can be gleaned from the block part number? Is there typically a casting date on a cylinder block and if so, where would that be?

Rob Edwards

Usually there's a casting date with week and year in a circle, in between the ribs on the rear face of the block in the flywheel area, at least on later engine blocks.

karl ruiter

The motor I built for my '79 also has a blank pad. I stumbled on a factory new replacement block on ebay as I was building it and went with that. It came to me as just the upper and lower block sections, the pistons and the rings. The pad looks just like yours. Sadly mine is a 4.5.

Mrmerlin

there are block /girdle ID numbers near the oil filter quadrant they should match

Hilton

Its likely a warranty block - usually they have "ATR" stamped on them, but not sure when that started, and thats definitely original casting surface.

kamaro

posted by mistake!