I have a 1971 MGB GT. When the Lucas alternator became weak, it needed replacement, and I learned here that a Delco conversion works. Here is my "experience."
- Alternator, AC Delco (remanufactured), 1978 Chevrolet Camaro 4.1L, O'Reilly part no. 01-0041, US$59.99 (Compare: US$84 for a rebuilt Lucas with lower output. Core charge is not included.)
- Home-made bracket, straight steel strap, 1/4" thick and 5/8" wide. Drill two holes in the bracket, 1.35" center-to-center, to match the diameter of the hole in the bent-steel bracket that mounts to the engine block and normally holds the rearward end of the Lucas alternator
- Junk-yard adjustable alternator bracket, Motorcraft no. D3AE-10145-DA
- Fan belt, Dayco "Top Cog", no. 15380. (38")
- Nuts, bolts, drills.
Step 1 - The alternator must be modified to make the sheves line up. The "ear" of the alternator, formerly used for attachment to the adjustment bracket, now mounted against the forward side of the "ear" on the water pump, has a bulge on its rearward side. It's as thin as a washer, but it has to go. Careful use of a hacksaw and light work with a file flattened things out nicely.
Step 2 - On the rearmost side of the alternator housing, attach the home-made bracket, from the alternator to the factory bent-steel bracket. You now have the unit reliably mounted, so that it swivels and the fan belt tension can be adjusted.
Step 3 - But you need a bracket to adjust and hold the fan belt tension. This mounts on where the original bracket was, and the Motorcraft bracket works like it could have been original equipment. Drill out the mounting hole with a 3/8" bit. The far end of the bracket, which is curved with a slotted hole, should be neatly ground and polished. You don't want it abrading the lines from the oil cooler.
Step 4 - Install the fan belt, and enjoy.
It would take another article to describe how to adapt the MG wiring to the Delco product. Needless to say, it won't "plug in" like the Lucas, but these links will help:
Final note: Even with this setup, the sheves don't line up exactly. But, they line up as well as with the Lucas alternator, which was just as crooked. My next steps will be to add an electrical radiator fan and a louder stereo. The extra amps should be good for something, after all.