Generator/Alternator
vs Model Year

Dave wrote describing his engine and alternator - One of the main problems I have with this engine -- The engine number (AE 320891) says it's a 1971 (the chassis is 1973-- 133-3001-550); I know that a rebuilt engine was installed in this car some time in the past -- I guess a '71 was available and would fit, so they stuffed it in. The '71 engine is supposed to be equipped with a generator; ours has an alternator, and it most certainly was NOT designed for this engine. It works just fine, but it's too big and interferes with the carburetor operation.

Rob responded - So -- when the engine died on your car as some point in its former life, someone replaced it with the 1971 engine, then just put all of the original components from the '73 engine back on it. The chassis number says that the car was manufactured probably in May-June 1973, right at the point when VW changed from the generator to the alternator.

The 1971 engine is one of the highest-power Type 1 engines. In the next few years they went to lower compression and 58hp to meet smog requirements etc. The next major improvement came in 74 with the AS series cases - an increase in the amount of aluminium in the magnesium alloy in the case, and they coped with extra heat better (65hp and FI I think).

So, it being a 1971 engine, it should have a generator; the alternator came out in 73. The first Motorola generators had an external regulator. That was then changed to an internally regulated alternator. There were other changes to go with the alternators too - the alternator stand has a different shape (a section of the cup is cut away), and both the carburettor linkages and the fuel pump required alterations to clear the fatter alternator body. They also fitted a fatter, longer fan belt, up from 905 x 9.7mm to 912 x 10.5mm. The stronger belt was needed to cope with the larger fan plus the increase in electrical power from the alternator. The original sized fan belt will still work, but it might not last a very long time.