#1 Conversion from dynamo to alternator
Posted: Tue Aug 01, 2017 11:01 pm
As my Day drew nearer, and I test drove her on Sunday, some charging and timing snags needed sorting out prior to the retrim, which should happen next week. And so my seller discovered that my 1963 series 1 3.8 had actually had a conversion done replacing the dynamo generator with an alternator - apparently well disguised with the old shell left in situ and the dynamo regulator cover also left in situ. This was quite a surprise. I thought we had established, at an early stage, with reference to the number imprinted on the regulator box, that the dynamo was the C42 30 amp version, rather than the C45 25 amp version (this to be expected, given that this change had already occurred in August 1961, according to Clausager p33). But this was all an illusion, based on the false assumption that the covers contained a dynamo and regulator rather than an alternator-regulator combo. I should presumably try to ascertain the specifications for the alternator.
I assume that I should stick with this (at least for now) and not now try to revert to the original dynamo system. Although the alternator is an unoriginal conversion on the 3.8, and does away with a rather quaint quirk, I suppose it falls somewhere in the same-ish category (tolerated and maybe even desired) as Kenlowe fan (also done) and extra callipers (also done), and not in the same category as 5-speed conversion (which had been done, but which I asked be undone to have the car's original Moss box restored and refitted). I understand that, generally, converting to the alternator tends to reduce charging issues (after all, this was one of the improvements in the 4.2). Anyway. Maybe I'm persuading myself. What's done is done, and I could always take a retrograde step at some later stage if I feel so inclined.
(By the way, insisting on restoring the Moss Box was one of the best things I did. It shifts really nicely, and my fears and nerves in this regard appear to have been misplaced. After a few driver errors, like going to reverse instead of first, struggling to find second, and going to first instead of third, I got used to the counter-intuitively small shifting area and felt I would quickly master this completely, without too much requisite double de-clutching skill.)
Anyway, back to the alternator conversion. What I should love to have some tips on from the boffins on this forum are the kinds of things I need to know that result from, or ought to be adjusted because of, such a conversion. I was, for example, wondering whether the polarity ought to have been changed to negative earth (if it even was positive to start with), whether the timing would be affected, and whether the manual choke operation ought still to be operated as it would have been with the dynamo (the 4.2 that came out with the alternator also came out with an automatic choke, methinks). Which instructions in the books aimed at the original 3.8 with its dynamo charging system must now be adjusted for the alternator system?
No doubt certain things one would do in the dynamo world, one would not do in the alternator world, and vice versa. Any help in this regard would be very much appreciated. I want to learn everything I can about my car, and things get complicated when the charging system is more akin to that of the 4.2, and one needs to know what adjustments this gives rise to, and what to look out for.
I assume that I should stick with this (at least for now) and not now try to revert to the original dynamo system. Although the alternator is an unoriginal conversion on the 3.8, and does away with a rather quaint quirk, I suppose it falls somewhere in the same-ish category (tolerated and maybe even desired) as Kenlowe fan (also done) and extra callipers (also done), and not in the same category as 5-speed conversion (which had been done, but which I asked be undone to have the car's original Moss box restored and refitted). I understand that, generally, converting to the alternator tends to reduce charging issues (after all, this was one of the improvements in the 4.2). Anyway. Maybe I'm persuading myself. What's done is done, and I could always take a retrograde step at some later stage if I feel so inclined.
(By the way, insisting on restoring the Moss Box was one of the best things I did. It shifts really nicely, and my fears and nerves in this regard appear to have been misplaced. After a few driver errors, like going to reverse instead of first, struggling to find second, and going to first instead of third, I got used to the counter-intuitively small shifting area and felt I would quickly master this completely, without too much requisite double de-clutching skill.)
Anyway, back to the alternator conversion. What I should love to have some tips on from the boffins on this forum are the kinds of things I need to know that result from, or ought to be adjusted because of, such a conversion. I was, for example, wondering whether the polarity ought to have been changed to negative earth (if it even was positive to start with), whether the timing would be affected, and whether the manual choke operation ought still to be operated as it would have been with the dynamo (the 4.2 that came out with the alternator also came out with an automatic choke, methinks). Which instructions in the books aimed at the original 3.8 with its dynamo charging system must now be adjusted for the alternator system?
No doubt certain things one would do in the dynamo world, one would not do in the alternator world, and vice versa. Any help in this regard would be very much appreciated. I want to learn everything I can about my car, and things get complicated when the charging system is more akin to that of the 4.2, and one needs to know what adjustments this gives rise to, and what to look out for.
