What is the best Alternator Rotor available today (2019)
- Thread starter jimbo
- Start date
- Status
jimbo
VIP MEMBER
- Joined
- Sep 25, 2004
- Messages
- 1,921
jimbo
VIP MEMBER
- Joined
- Sep 25, 2004
- Messages
- 1,921
- Joined
- Dec 28, 2008
- Messages
- 2,035
If I found such a condition I'd want to know why the bore is worn, being loose would be my first guess. If that is the case than I would want to know if the crank pin it fits onto had suffered any damage. If you have already put those considerations to rest then the question, in my mind, would be, is there any difference, or is there a threshold, in the gauss numbers.
Dynodave comes to mind for such a question; certainly others may have some knowledge here; I do not. My gut tells me that new rotors may be created with equal gauss, and may all be made at the same factory, but I can't say for sure.
Best
jimbo
VIP MEMBER
- Joined
- Sep 25, 2004
- Messages
- 1,921
When flipping the rotor around and installing it backwards on the unused ,unworn bore it fits on the crankshaft much better, so my deduction is a worn bore on the end that is fitted onto the crank normally
- Joined
- Dec 28, 2008
- Messages
- 2,035
OK, but...The rotor, with key, shouldn't (ever) be allowed to move in any direction once torqued. If the crank pin where it fits measures consistently at .750 (IIRC, plus or minus tolerance), or what ever, then your machine must have been fitted with a "Monday" rotor, either by the factory or some other agent. My only concern her would be the crank pin.
Hopefully someone will comment on the gauss numbers to answer your original question; I'll stay tuned.
Best
- Joined
- Dec 3, 2012
- Messages
- 3,675
I am going to say the 'best is a NOS rotor based on the last 40 years or so.
https://chris-knight-mcs.co.uk/stators-and-rotors/lucas-rotor-54210413
I got a complete 3 phase kit some time ago from the UK (Rexs Speedshop) and the Lucas rotor is a precise push fit on the crankshaft end.
The stator and rotor came in Lucas branded boxes and would hope they are made in the UK.
The Chris Knight website as above did have a couple of versions for the same parts, it seems Lucas can be Lucas but not always with the Wassell murkiness.
Edit.
https://www.rexs-speedshop.com/
I did note an original Lucas rotor did have clearance on the crankshaft as far as the bore went but doubt it would be like that from new.
What I would like to do (Not that it has gone beyond a thought) is move the rotor/stator inward via a duplex sprocket (Mercedes Benz primary chain)
Last edited:
- Joined
- Nov 20, 2004
- Messages
- 20,087
That would be a choice between a Wassell rotor and a Lucas rotor....also made by Wassell.
Wassell rotors were made in Taiwan (it said so on the box).
Not that one as it's RM 13/15.
The later the (genuine Lucas) rotor the better:
http://www.oldbritts.com/11_068100.html
- Joined
- Dec 3, 2012
- Messages
- 3,675
I thought you might say that, I thought the Chris Knight website would have the electrics list they had before that stated which parts were UK made (I might have missed it) from when (iirc) both You and Kommando replied on BritBike.com (when I got the kit from Rex SpeedShop)
It seems even in a world of CadCam and CNC, quality parts are not a guarantee but the Lucas branded rotor I got seemed a good fit at the minimum, it lasting 40 years will most likely not be a factor for me.
- Joined
- Oct 10, 2017
- Messages
- 1,120
hi well, I have recently replaced rotor/stator on T120 with wassell brand I put lucas rotor/stator on commando when I built it put new wassell rotor only on 68 A65 a few months ago.....based on voltmeter checks after rides..the wassell combo charges battery slightly more so I reckon they are all about the same..PS I had read somewhere that wassel rotor would not fit original lucas stator (as in the one on the A65) but I did not find that to be the case
- Joined
- Dec 28, 2009
- Messages
- 5,133
I've fitted both brands over the years with no problems with fit. Maybe D.D. has done magnetism tests and how much stronger one is over the other. Earlier ones can have the center steel locking sleeve separate from the body so always buy the welded latest type.
- Joined
- Jun 1, 2003
- Messages
- 2,146
i would guess that you would see that NO 2 would test the same from one brand, much less from brand to brand. as to welded rotors i would think the only way you would see one is very old stock as in 40 plus years old.
- Joined
- Nov 20, 2004
- Messages
- 20,087
I thought the whole 'welded' rotor thing had already been found to be a myth?
https://www.accessnorton.com/NortonCommando/lucas-alternator-rotors.18376/#post-273548
http://www.britbike.com/forums/ubbthreads.php/topics/582074/re-loose-alternator-rotor#Post582074
- Joined
- May 28, 2003
- Messages
- 2,590
I would believe strongly it is likely a myth and I could tell in an afternoon if one of the identified PN units was delivered to me.
I know John Healy personally though we are not bosom buddies or enemies, I do like him...
In his post he says you can't weld magnets. Generally agree. However I don't know how many decades he spent in manufacturing environment.
In my 30 short years in MFG (after 20 in USAF), I did learn it is entirely possible, though uneconomical , to furnace braze the load metal to the machined hex core. Next call it "welded", which it is NOT, turn it over to the marketing division and turn them suckers loose!!!!
$$$$$Probably a myth. Make sure to gauss it before you ship it!
I have a gausser that I built for gaussing up magneto's but balked at the work required to make one for regaussing a stupid pre-exploded rotor.
Last edited:
marshg246
VIP MEMBER
- Joined
- Jul 12, 2015
- Messages
- 4,126
I really have no clue, but I would think you could weld then magnetize. I know we did that with some plant parts when I worked in a steel mill. Also, there's more to a rotor than the magnets. I don't know how or if it is possible to weld the center to the metal surrounding the magnets but that's what would make sense. The point is to not have the center of the rotor turn in the rotor. "weld" gets used loosely today since there are so many methods. When an old man taught me to braze when I was 16, he called it welding - not technically correct but none the less, sticking metal together.
The current "genuine Lucas" rotors do appear to be high quality - I see nothing resembling welding but then I have no x-ray vision
The current "genuine Lucas" rotors do appear to be high quality - I see nothing resembling welding but then I have no x-ray vision
- Joined
- Dec 28, 2009
- Messages
- 5,133
Big Peter Turner made a way of modifying the stator itself to adjust clearances all around not by way of bending the studs as per manual but filing away a bit of the stator stud holes. Then the 3 nuts can be nipped down to match up even clearance all around which is essential.
- Status