Alternator conversions for 3 litre cars

Have any 3 litre owners got experience with alternator conversions on their cars?  I am investigating alternators fitted inside a dynamo housing, on the principle that they should give better charging, weigh less, and eliminate the control box.  There seem to be 2 alternative available units to replace a C45 dynamo, e.g. Dynalite, Dynator and from Stealth (Dynamator). They appear very similar but prices are quite different.  Dynator seems to be (mostly) supplied with a pulley / fan, and Stealth without.  A couple of retailers advised me just to fit the old C45 dynamo pulley, but I have my doubts it would spin fast enough. Existing pulley is 95mm od, alternator pulleys may typically be approx. 60mm od for a fairly low-revving engine.  I would be interested to know if anyone has experience, good or bad, of such units, and of suitable pulleys / suppliers for them in cases where the unit is sold without a pulley (at considerably lower price).  Giles Lacey Posted by lacey giles 21/04/2016 23:10:17

Giles,  What's prompting the thoughts for the conversion? The original setup is good for about 19 amps or about 230 watts. With some of the low current LED technology available we can more easily live within 230 watts.  I would appreciate your thoughts.  Richard Melbourne Posted by RichardWallach 24/04/2016 00:05:19

Reasons which prompted a study of C45 pattern alternator conversion are as follows:  - Control-box (regulator) failure, then the original 1960 C45 dynamo was found to be on it's last legs,and when opened-up I found someone has already repaired it, albeit keeping it running (just). While looking through various repair / replacement options, I found many older cars being fitted with alternators, and a C45 pattern alternator has become available in +ve earth version. Output is very healthy even at low revs (providfing the pulley-size is correct for the alternator / rpm characteristics). Usually quoted as 40A, so on our cars it should never be running on the limit even with a low battery, all lights and wipers on.   - I found that control-box (regulator) and dynamo repairs and spares are becoming difficult and costly to source.   - Control box points are prone to wear / erosion etc. changing the regulator characteristics, or simply not working correctly. Especially after a long, damp, winter lay-off.  - Replacement control boxes are mostly Indian copies, just not worth using. Failure of the control box could wreck a good dynamo. Genuine Lucas regulators are scarce, expensive, and always need skillful setting-up.  - Best option for a regulator is a solid-state unit in the old control-box case, providing the dynamo is 100% good. Solid state regulators are not affected by winter lay-offs and requires no setting-up, but they are not cheap.  - If the dynamo is wearing out, a rebuild of the C45 unit is not so cheap, and C45 spare parts are not so easily available.  - Therefore I am researching the Alternator route because prices for the C45 based unit are getting affordable, and it gives another option to update the car with no visual changes and good functionality. If it is not feasible, I will just convert to a heavy-duty solid-state regulator, and rebuild the old C45 dynamo. But if I don't investigate, I won't learn the options available.  - You make a very good point about LED bulbs. I have LED's for the Lucas L464 rear lights / indicators, and front indicators (built into 1130 units) so far with excellent improvements to intensity / safety. Also an electronic 3-pin flasher unit (same connections as original Lucas) for a reliable flash-rate regardless of engine speed, and to run the brighter LED indicator bulbs. But I am not yet 100% convinced about the beam-focus of LED bulbs in British Pre-Focus P700 headlamps or SLR driving lamps. That is `work in progress´so I still use traditional headlamp / driving lamp bulbs for now.  Not too long winded I hope, Giles Posted by lacey giles 24/04/2016 20:32:47

Giles,  Thanks for the reply. If you decide to keep the original set up then Classic Dynamo and Regulator Conversions can provide the pos. earth conversion for the Lucas regulator. As for the generator if you need parts let me know as many new old stock can be sourced here in Melbourne.  Let me know how you get on and the cost too.  Regards  Richard Melbourne Posted by RichardWallach 24/04/2016 22:27:36

I will certainly repair and keep the original dynamo set-up. Good tip about Classic Dynamo and Regulator Conversions, I have sent my failed Lucas control box to them for conversion to electronic regulator.  Thanks for your offer of help with old C45 dynamo parts. I may well be in touch if I can't locate them locally.  I will proceed with the `C45´ pattern alternator system as a trial more than anything, which gives me time to work on the dynamo as required.  More as the work progresses,  Giles Posted by lacey giles 25/04/2016 22:59:08