The engine that was originally installed in your VW at the factory, had an engine number
stamped into the case, just below the generator stand. This number consists of one or two
letters followed by a series of numeric digits. The engine number does not equal the
vehicle's VIN, but VW kept records of each new vehicle's original engine number code, and if you write to
them you can get this information (for More Info.
If your engine has a number plate attached to the case covering the original number, you may
have a case that was rebuilt by the factory (and re-numbered at that time). If your case has no
at all, you have a newer case manufactured by an after-market supplier of replacement engines.
Unfortunately, it's doubtful that your VW still has it's original engine. Air-cooled VW engines
are very interchangeable so when your car's original engine finally died, the mechanic probably
just installed a rebuilt engine that came out of another VW. The engine in your VW may have
come from a different model (e.g., your bus may have a bug engine) or may not even be the
correct displacement (e.g., your '66 bug originally came with a 1300cc engine but now it
may have a 1200cc engine). To add to the confusion, the displacement implied by your engine's
code number may be incorrect now because a previous owner upgraded the pistons and barrels to a larger
displacement (e.g., you have a 'D' numbered case which originally was a 1200cc engine, but someone
has installed 1300cc barrels and pistons on your case to increase the displacement and therefore
the horsepower). Some restorers don't really care about engine numbers, but if you're trying to
research what's currently installed in your VW, or what series engine should
in your VW, the table below should help. Note; when you read the engine# stamped into your case, make sure
you include the left most letter, which may be partially obscured by the engine case stud.
For more detailed information about specific ranges of
engine numbers, check your shop manual or find a copy of Muir's "Idiot's Guide"
(for More Info.