Triumphrat

DerryUK · 11-20-2012, 12:07 PM

I spotted that Tri-Cor are selling high-power Sparx alternator rotors so bought one to test. I compared the Sparx to a new Wassell and an original Lucas rotor.

I tried them in two stators, one an unnamed stator that is usually advertised as suitable for Royal Enfield and made in India. The second stator was a Lucas 47205A two wire 120W nominal output.

The voltages are AC on my meter and I have used a 1ohm load at 3000 RPM.

Unknown..Lucas.....12.2v.....149W
.............Wassell....12.8v.....163W
.............Sparx......14.9v.....222W 59W extra

47205A...Lucas......10.8v.....117W
.............Wassell....11.0v.....121W
.............Sparx......13.1v.....171W 50W extra

50 Watts extra power is well worth having in anybody’s book. The rotor costs just under £80.

rambo · 11-20-2012, 12:50 PM

That looks impressive.I buy mine at autojumbles for £10 though.If i ever buy a new one,this is helpful info.Cheers

loxx101 · 11-20-2012, 02:32 PM

That's awesome! I have been thinking about going down the Sparx rotor route for a while now as I want to run Tri-Spark with no battery.

Quite surprised the rotor actually is that good. Nice one!

DerryUK · 11-20-2012, 02:57 PM

<Quite surprised the rotor actually is that good>
Agreed, plus of course if you have a three-phase stator you'll squeeze even more power out of it.

loxx101 · 11-21-2012, 04:55 AM

I have just been given a three phase alternator as well. Happy days!

For the money, it sounds like replacing my rotor is a sterling idea.

DerryUK · 11-21-2012, 05:34 AM

As has been said to me elsewhere these rotors won't do a standard zener any good, you need a proper aftermarket rec/reg.

loxx101 · 11-21-2012, 06:14 AM

Yeah, I found a cheap new one on an eBay shop.

It seems like a worthwhile cheap improvement for reliability.

JohnA · 11-21-2012, 08:26 AM

Could the poor performance of the original Lucas rotor be due to it having lost some of its magnetism? And would the improved performance of the Sparx item be due to stornger magnetism that they've somehow managed to build in? I can't think what else could be changed on a rotor to make any difference to output (but then I am not any kind of electrician!)

loxx101 · 11-21-2012, 09:17 AM

Well they claim it is a stronger magnet, yeah. I imagine a new lucas rotor would be substantially better than old.

DerryUK · 11-21-2012, 12:47 PM

<Could the poor performance of the original Lucas rotor be due to it having lost some of its magnetism>
The Lucas rotor generates 117W with the 120W stator which is pretty close. I have measured worse than this with rotors. See here ...
http://www.scribd.com/doc/102021181/Lucas-Stator-Log-4

As Lox says it's down to stronger magnets in the Sparx rotor. Like a lot of sellers though they just say stronger, more powerful etc. which is pretty meaningless. Even saying 200W doesn't really mean a lot unless you know the voltage and load it was measured with.