VW Engine Codes

Alphanumeric Volkswagen Engine Codes were stamped on VW Engine cases at time of car manufacture to convey information about the size and specs of the engine. Because VW offered multiple engine sizes and made changes to their engines independently of model changes, they used Engine Codes instead of relying on VIN numbers for this purpose. There is some engine information that can be derived from VW VIN Numbers for pre-1968 vehicles.

From the first 1 or 2 digits of a Volkswagen Engine Code you can derive the approximate year and engine size. The remainder of a VW Engine Code is essentially a serial number.

Chart Information Crowdsourced at TheSamba.com

Replacement cases
These cases were VW engine cases that were sold from VW but never issued in an actual production vehicle.  All are dual-relief cases with 100mm oil passages. Example: Information from a 5/73 USA service bulletin issued 5/73: Engines with the re-manufactured symbol, a letter, a number and ending with X, indicates a VW Exchange engine.  Before Oct., 1968 the X was not stamped onto the block.From April of 1972 Shortblocks were sold with the VW remanufacture symbol followed by a letter. No numbers were used, you were to stamp in the old engine number.
F1	1300/1600
F2	1300/1600
DO	40hp if last digit is “X”
D1	40hp part
AD	1600
AK	1967-1974 1500/1600
AM	1600
AS	Sometimes seen listed as Super Beetle case for 1973-onward

Exchange engines

These engines are normally marked with a VW recycle symbol and an X at the end. Example: Information from a 5/73 USA service bulletin issued 5/73: Engines with the re-manufactured symbol, a letter, a number and ending with X, indicates a VW Exchange engine.  Before Oct., 1968 the X was not stamped onto the block.From April of 1972 Shortblocks were sold with the VW remanufacture symbol followed by a letter. No numbers were used, you were to stamp in the old engine number.