Converting to Three Phase

In case I end up converting to a three phase alternator I think this is the list of parts I need:

I have a good rotor so I should just need the stator and a new rectifier/regulator.



Is there anything else I'll need to change?

I bought one from Tri Spark last year and what you have is all I used....I did wonder about using a 40 year old rotor though..... :roll:
I mounted the reg under the battery tray as I could not find anywhere that it looked good/hidden.
Bit of disconnecting to do, the charge simulator thing on the spring and the diodes.....great feeling binning those.
I miss the charge light....

72Combat said:

I miss the charge light....

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http://www.aoservices.co.uk/data/lvs.htm

I prefer a Podtronics three-phase regulator and a Lucas 47244 three-phase stator. If I need a rotor, I'll go with a welded Lucas. I have never used Wassell rotors and stators, but I am not a fan of the Sparx stuff. The Podtronics regulator does not appear to be as sensitive to RF interference as I run solid core wires and non-resistor plugs on my Interstate with no charging issues. The Sparx regulator/rectifier requires 5K ohm caps or resistor plugs.

As L.A.B. says, a low voltage switch is the easy answer to using the warning light, but a voltmeter is more informative.

Dave,

Vintage 1970s rotors are magnetically soft and degenerate over time; they see the full internal temperature and lots of vibration. When I did the 3-phase conversion a few years ago, all of the suppliers strongly recommended a new rotor; it was about 90 bucks, as I recall.

The OEM assimilators varied in design over the Commando series, and I found interpreting the warning light to be ambiguous. Modern after-market devices, like AO, simply compare the peak output voltage of the alternator, or in some cases the battery voltage, to a voltage reference, say 12.5 volts. When the alternator output is used, the warning light acts as a simple voltmeter and gives an unambiguous binary reading of the alternator; illumination means peak alternator voltage is less than 12.5 volts. Some devices use two voltage references, and a very few use several to give a readout of, say, five voltage ranges. Keeping it simple, I use a simple aftermarket device with the original warning lamp while riding, and a voltmeter in the shop. There is no need to give up the warning lamp when converting to 3-phase charging.

I just put a Sparx three phase high output alt & the reg/rec on my 850. I got rid of the old Lucus stuff & fabbed up a bracket to mount the reg/rec like CNW does. I can't even tell you how much better my lights are now!! Even my tail light is so much brighter now a friend told me he thought my brake light was stuck on! My old rotor had enough magnetic power to stick to a wrench & not fall off when lifted but I put the new one on anyway. I don't know anything about the differances in quality of the differant brands but I can say I'm real happy with the Sparx stuff so far. Did have to ream it to fit as so many others have had to do but I have access to a shop so it was easy. Might piss someone else off if they didn't have a easy way to do it.

I too have the Sparx 3 phase and couldn't be happier. I left the old rectifier in place and used spade terminals on the regulator wires so that in the event of electronics failure I could revert to an unregulated single phase system just to get me home.

I have an electronic assimilator that works just fine with the 3 phase system, though the bulb comes on dimly at idle.

I fitted a Sparx 3 phase to my 71 Triumph Bonniville along with the resistor plug ends. It shows charging on the amp guage with a 55W H4 headlight bulb on at anything above 1000RPM. With the old Lucas system and headlight it did nothing till over 3000 RPM. That sold me enough to want to fit one to my Norton, or any other Brit bike I may have with an alternator charging system. You can never have enough light.

rick in seattle said:

Dave,

Vintage 1970s rotors are magnetically soft and degenerate over time; they see the full internal temperature and lots of vibration. When I did the 3-phase conversion a few years ago, all of the suppliers strongly recommended a new rotor; it was about 90 bucks, as I recall.

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My rotor is new, along with the single phase stator. Correct me if I'm wrong but there is only one rotor?

swooshdave said:

My rotor is new, along with the single phase stator. Correct me if I'm wrong but there is only one rotor?

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There are more than one rotor, but all will work. The early style Lucas rotor is notorious for becoming loose on the center, but the later Lucas "welded" rotor is much stronger. As I said in my earlier post, Wassell also supplies rotors, but I have never used one. The Sparx rotor sometimes has a taper misfit.

I have the Sparx 3ph also and got everything in one kit from Lowbrow including the sparkplug caps.
Linky http://www.lowbrowcustoms.com/index.php?l=product_detail&p=349

Dave,

When I read in your post that you had a "good" rotor, I interpreted that to mean "original but serviceable". If it is indeed a new rotor, it will work fine if you convert to a 3-phase system, subject to the mechanical concerns raised by Ron L. Like many of those posting on this topic, I installed the SPARX 3-phase system; the new rotor installed easily and with no wobble from the taper.