What is the best Alternator Rotor available today (2019)

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A O Services and Villers in the UK will remagnetise alternator rotors, Villers charge £15. TMS Motorcycles list Lucas e.g. Wassells and non Lucas LAP UK made alternator parts.
 
kommando said:
A O Services and Villers in the UK will remagnetise alternator rotors, Villers charge £15. TMS Motorcycles list Lucas e.g. Wassells and non Lucas LAP UK made alternator parts.
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That will explain why I couldn't find that list mentioned on the previous page of this thread, I was looking on the wrong website.:oops:
 
I believe that the most important issue when fitting new rotor or stator or both, is ensuring good rotor to stator clearance.

On my previous engine build, I ensured I had the requisite .010” clearance using the original rotor and a new stator. But upon disassembly I saw signs of rubbing and an unhappy stator.

So, on the latest rebuild, I had my machinist mate properly measure the ID of the new stator and OD of the new rotor. There was less than .010” clearance, and thats best case, ie without any minor misalignment when assembled.

I had him turn the rotor down to give .020” clearance all round. I then assembled it as shown below. The plastic ‘sleeve’ is to ensure even clearance as things are tightened up and (this should be obvious, but just to be clear) it’s then removed before being run.

What is the best Alternator Rotor available today (2019)
 
We’ve machined down a couple of rotors now in the lathe - they machine very nicely.
Just need to keep the air compressor blowing the swarf away as it cuts.

What is the best Alternator Rotor available today (2019)

I have found the new genuine Lucas rotor and stators to be made to a tighter tolerance than the old ones.
That would usually be a good thing, but in this case it made me uneasy given the possibility of crank flex, which is why we now machine them.

I’ve seen zero noticeable degradation in output/charging.
 
i did make an error in my post as i meant to say non " welded " and yes i also know about the myth but used the common terminology. I also don't say I "fixed " it but instead I say I returned it to operating condition.

L.A.B. said:
I thought the whole 'welded' rotor thing had already been found to be a myth?
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the question is, is there any difference it the two now that wassel owns the lucas brand other than markings. my guess is no.


L.A.B. said:
That would be a choice between a Wassell rotor and a Lucas rotor....also made by Wassell.
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I know nothing about the difference in rotors.

However, I had spoken to several people when Wassell bought into the Lucas name (it’s just a paper-based licensing agreement) and was told that in the case of the stators, the Lucas branded components go through several stages of additional final finishing and quality control/checking processes over and above the Wassell parts.
The batch numbers are smaller, and the production stages are tracked and traceable.
 
jimbo said:
weird, Lucas is still calling them welded
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Yes, but what does "superior welded centre" actually mean? If it is supposed to mean the magnets are welded to the core then to date, there has been no evidence of it being true.

http://www.britbike.com/forums/ubbthreads.php/topics/581460/re-loose-alternator-rotor#Post581460
"John Healy"
"The term "Welded Rotor" came about after one exploded on the Isle of Man. I always wondered what that term meant so one day I took to my lathe and took a new rotor to pieces. And that is just what I got... pieces. You guessed it... it wasn't "welded" at all. After many years seeing these come apart I suspect the term Welded Rotor came out of the marketing department."
 
Fast Eddie said:
I believe that the most important issue when fitting new rotor or stator or both, is ensuring good rotor to stator clearance.

On my previous engine build, I ensured I had the requisite .010” clearance using the original rotor and a new stator. But upon disassembly I saw signs of rubbing and an unhappy stator.

So, on the latest rebuild, I had my machinist mate properly measure the ID of the new stator and OD of the new rotor. There was less than .010” clearance, and thats best case, ie without any minor misalignment when assembled.

I had him turn the rotor down to give .020” clearance all round. I then assembled it as shown below. The plastic ‘sleeve’ is to ensure even clearance as things are tightened up and (this should be obvious, but just to be clear) it’s then removed before being run.

View attachment 13556
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Yes , the milk carton plastic sleeve trick really does work well to centralize with even gap all around the rotor/stator. It should pull out without any fighting with it. If so ,loosen up the stator and try again. Fettling.
 
kommando said:
A O Services and Villers in the UK will remagnetise alternator rotors, Villers charge £15. TMS Motorcycles list Lucas e.g. Wassells and non Lucas LAP UK made alternator parts.
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Anyone know of a remagnetizing service this side of the Pond ? I'm in the Greater Toronto Area (GTA) in Canada. I've got 3 rotors that could use checking and then possibly remagnetizing . By the way , I hope everyone kept their rotor Keeper shells (2) that too often get tossed when installing that shiny new rotor. They keep the magnets from bleeding energy outwards when in shipping or storage conditions (or in our situations basket case machines...).
 
from my last tech session measuring a milk crate full
North is above the keyway N-S-N-S-N-S

New 2.23k 98 05 ? 54202298 is 2230 gauss

used
2.23k 9/75- 2.02k--2.01k 8/72-1.93k-1.92k-1.83k-1.79k-1.68k-1.63k-1.8k-

1.75kloose-

1.03k rubbed on stator-1.44k rubbed-1.99k rubbed
They will ALL stick to a screwdriver -sic
 
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I am surprised no one mentioned that the centers become loose.
 
jimbo said:
I am surprised no one mentioned that the centers become loose.
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The early ones should never be used. Huge crankshaft forces eventually cause the centers to get loose from the stator body. Junk them well before this happens . My bud had this happen roadside. We pulled the primary outer cover and a white atom bomb of smoke came out. That and rotor chunks falling to the pavement. After shock and cigarettes and thinking we decided he could make it home by open primary cooling and all lights off with outer cover bungee corded to the passenger seat.
 
Are those rotors balanced, even if so a recheck could never hurt.

I remember reading an article although can't recall the exact numbers where an ounce of out of balance out there on the end of the crank was (iirc) equivalent to 126 lbs at reline (4 cylinder bike)
 
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