Dynator

[Charles Frodsham]

Has anyone any experience of using a “Dynator” on the Flaminia?

[lancianut666]

I have read /heard/dreamt that they are prone to overheating as the outer case is meant to look like a dynamo, I'm sure a google search will give you some information.

[Kevinlincs]

A decent dynamo is more than adequate for classic use so why bother with a change to an alternator?
Dynamos don't perform as well as an alternator when compared to modern use which requires heater blowers/lights/wipers/heated window etc etc to be functional at low revs, that's where the low speed prevents enough charging coming through.
But for classic use where the above situation would hardly ever arise (not used in dark/cold/rain) then a dynamo will cope just fine.
That's what I'm doing with my Flavia, I had it refurbished ready for refitting when the time comes. It provides more than enough amperage for the electric fuel pump and ignition circuit plus a radio and maybe a supplementary radiator fan.

[Richard Fridd]

 My Flaminia original fitment dynamo does not positively charge,  below 9000 rpm engine speed, necessitating a brisk tick over to avoid discharge. Is this normal?
   Advice welcome,

     Richard

[peteracs]

9000? Interesting engine, tell us more…….

Peter

[Spider2]

Does it matter if the battery discharges for short periods? It will soon charge up again. Assuming the battery is about a 70 amp hour capacity I cannot imagine the discharge to be more than 5-10 amps at most so it should cope with even the worst M25 traffic jam if my maths is correct. Before alternators were standard fit I don't remember people being bothered about it and certainly don't recall rows of cars broken down with flat batteries. Of course in those days most cars were fitted with ammeters which helped with monitoring amperage flow and direction. What I do remember is that if the battery was a bit low, say after a difficult start, the rate of charge from the dynamo was huge, a least 30 amps. A useful gauge to have in a car with a dynamo.

[Richard Fridd]

9000? Interesting engine, tell us more…….

Peter

  900 only I'm afraid

[Jay]

Hi Richard, 900rpm sounds about right before a dynamo starts charging, so should be be fine for most driving. Only issue that i have experienced is driving at night on a low charged battery, with dim lights, but this rarely happens as i have been driving during the day.

[Mikenoangelo]

A slight aside here. I have used Lucas C40 dynamos in place of originals on a couple of vintage cars with complete success by gearing them up about 20% by changing drive pulleys to compensate for the lower engine revs and higher axle ratios than the 50's and 60's cars for which the C40 was intended. Our 1925 Salmson 1100cc Twincam is geared at 19.5mph per 1000 rpm and with the C40 copes very well with the VSCC Measham night rally which involves 6-8 hours of driving at night in January .
Mike

[Richard Fridd]

 Now there is a solution which I should have discovered a while ago. Does anyone know of a suitable pulley upgrade and how difficult changing the pulley in situ is? I only use around 2500 revs so there shouldn't be a problem with high speed damage.

  Richard

[Spider2]

Good plan. Either a larger crank pully or smaller dynamo pully. Which would be easier?

[Richard Fridd]

Dynamo access