I thought I'd move this query over from the 'parts for sale section'...I think the post on Norton Magdynamo mountings is long enough already... ...Ian

I'm interested in magdyno base drilling variations...

The ones I know of are..

4 plain holes fitted with 4 dowels for BSA applications..centre hole unmachined.

4 tapped holes fitted with threaded dowels for BSA applications..centre hole unmachined.

4 tapped holes for Norton applications...centre hole unmachined

5 tapped holes for use on Ariels (which uses the two end ones and the centre one..

4 tapped holes for Royal Enfield applications..?...with dowels?..centre hole unmachined..

Direction of rotation features, pick up positions etc. to suit application...

Any comments..or any more variations?

The base to armature centreline dimensions are constant as far as I am aware...Ian

email (option): ian@wright52.plus.com

Hi Ian

I have a Rob van Meel copy of a Chilwell spare parts list, LV6 MT8 Vocabulary of Army Ordnance Stores dated November 1943 which lists all the components for a number of M01 MagDynos, but it doesn't state which fits which bike.

M01/4/AC20
M01/4/L/O
M01/4/AQ4
M01/6/AG4
M01/6/L/O
M01/6/LI-O
M01/6/H3

I presume they are all different, but I have never compared all the part numbers to see how they differ.

Do the brass plates attached to WD magnetos have different model numbers?

Rob

email (option): robmiller11(a)yahoo.co.uk

Again I can't quote number to make/model of bike at the moment without some time looking through parts lists. But the variations would included:- left or right side pick up. left or right side points end plate for the cable, and direction of rotation.

Ron

email (option): ronpier@talk21.com

Hi Ron..Yes, a part number variation wouldn't just apply to the base fixing arrangements as you point out....

I think the most likely way to determine how many different ones there are will come from observation, not parts lists, where any difference will result in a different number but details are not given as to what the differences are...Ian

email (option): ian@wright52.plus.com

From the 'Radco' book :-

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This is a chart which pre-dates the post-vintage machines which we are interested in but the 50mm x 50mm fixing centres do seem to apply to the MO1. It gives no clues as to the individual fixing systems ordered by each manufacturer but suggests that there are two main sizes of motorcycle magneto.

In terms of Nortons, I've found reference to MO1/1/AG4, MO1/2/AG4 and MO1/4/AG4

These will all be clockwise units with pickup to the right. Four threaded holes under. Presumably the middle didgit simply referred to revisions - cadmium plating instead of nickel etc.

Hi Ron..Yes, a part number variation wouldn't just apply to the base fixing arrangements as you point out....

I think the most likely way to determine how many different ones there are will come from observation, not parts lists, where any difference will result in a different number but details are not given as to what the differences are...Ian [/quote]

Yes but some time looking at numbers in parts lists with what I have already researched as a correct mag, might indicate some applications from Rob's list. Ron

email (option): ronpier@talk21.com

A randomly picked 42/43 WDM 20 parts list gives the number M01/4 AC20 for the magdyno...

Perusal of parts lists for all makes would presumably turn up the appropriate numbers for the complete magdyno for those as well...

However, this would still not clarify the number of holes drilled and tapped (or not) in the mag base or whether or not in the case of the M20, plain or threaded dowels were fitted...Ian

email (option): ian@wright52.plus.com

Hi Ian

Here is an unrestored mag which I have put by for my WB30, the brass plate appears to be dated 8 40 the model is marked M01 4 AC20 and where one stud is missing it doesn't appear to be threaded.

I realise the plate is held on with two screws and could have been swapped at some point in the last 75 years however its still a piece of evidence to consider.

Rob

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email (option): robmiller11(a)yahoo.co.uk

I think that most of the WD Mag's (for the magdyno units) carried the same label (Type M0 1/4 (was there previous numbers ???)..........

I think the fitting applications however, depending on the base drillings for different bikes, were identified by stores however.............?

Whilst in principle the mag pick-up should always be on the side furthest away from the cylinder barrel, surviving examples today prove that both "near to cylinder" and "furthest away from cylinder" for mag pick-ups were employed with the same base-drillings for both types............there was a war on after all and you couldn't be that "picky"............

The Norton 16H and Big 4 however uses a mag that has the advance and retard cable entering from the top-left (as viewed from the near-side of the bike) so at odds with the other WD types fitting a magdyno..........but you CAN still use a right-hand fitting however even on a Norton..........

I think that most of the WD Mag's (for the magdyno units) carried the same label (Type M0 1/4 (was there previous numbers ???)..........

I think the fitting applications however, depending on the base drillings for different bikes, were identified by stores however.............?

Whilst in principle the mag pick-up should always be on the side furthest away from the cylinder barrel, surviving examples today prove that both "near to cylinder" and "furthest away from cylinder" for mag pick-ups were employed with the same base-drillings for both types............there was a war on after all and you couldn't be that "picky"............

The Norton 16H and Big 4 however uses a mag that has the advance and retard cable entering from the top-left (as viewed from the near-side of the bike) so at odds with the other WD types fitting a magdyno..........but you CAN still use a right-hand fitting however even on a Norton..........

['Here is an unrestored mag which I have put by for my WB30, the brass plate appears to be dated 8 40 the model is marked M01 4 AC20 and where one stud is missing it doesn't appear to be threaded.

I realise the plate is held on with two screws and could have been swapped at some point in the last 75 years however its still a piece of evidence to consider.']

Hi Rob....I would say that is the correct mag for your B30..

Basically the same spec. as that fitted to the M20...I have had a number of wartime mags pass through my hands with the 'plain dowel' fittings in the base...Ian


Steve...['Whilst in principle the mag pick-up should always be on the side furthest away from the cylinder barrel, surviving examples today prove that both "near to cylinder" and "furthest away from cylinder" for mag pick-ups were employed with the same base-drillings for both types............there was a war on after all and you couldn't be that "picky"......']


The problem is we have no idea when all the various mags were fitted or from where they originated...Post war fittings and 'civvy' alterations are all possible apart from REME swapping things around...

No problem fitting an Ariel mag to a Norton for example...Or a Norton mag to a BSA with the addition of the 4 threaded dowels...No doubt there are many permutations between the various makes...

My assumption is that each bike had the correct mag 'factory fitted' initially...Ian

email (option): ian@wright52.plus.com

I think when Lucas Mag's were overhauled in workshops Ian I doubt if they bothered changing or marking the Lucas manufacturing plate..........never seen one altered nor changed (seemingly) in my time.............(even with mag's overhauled post-war as evidenced by the internal fittings).......

Yes the Norton Mags have the cable at the left side, which still make them 'tight wire advance' as the mag revolves anti clockwise as viewed from the points side. Royal Enfield Mags also have the cable at the left side but the mags revolve clockwise at the points end. As far as I can think, the Enfield's are the only WD bikes with slack wire advance. Ron

email (option): ronpier@talk21.com