The BSA A7-A10 Forum

Technical => Lucas, Electrical, Ignition => Topic started by: 900triple on 30.09. 2011 19:49

Title: Lucas E3L - is this the right one?
Post by: 900triple on 30.09. 2011 19:49
Hello,

I'm at the stage of needing to have the dynamo on my 1951 A7 plunger rebuilt. From the box of bits came this E3L. Question is...will it be okay on this engine? The sprocket end looks different. Before I go to the expense of rebuilding it I need to know!!!!

Also - it has a 15 tooth sprocket. Speaking to Paul Goff a 6v rebuild should be ample working through a DVR2 as the rest of the bike is 12v but should I keep this sprocket or go for the standard 11 tooth effort?

Advice gratefully received.

Alan
Title: Re: Lucas E3L - is this the right one?
Post by: Beezageezauk on 30.09. 2011 20:36
Hi Alan,

Just a thought or two!!

If you use the 15 tooth sprocket:-

Firstly, you would need to remove the sprocket from the armature when fitting or removing the dynamo because it won't go through the hole in the inner timing case.  There is just enough room for the 11 tooth sprocket to go through.

Secondly, You would need to get a slightly longer chain to make up for the extra teeth.  All the dynamo drive chains that I've ever used on A7/A10's were endless but longer ones (and split links) may be available.

I can lend you an 11 tooth sprocket if you want to see if it fits the armature ok and check alignment.

As I said at the start...Just a thought.

Beezageezauk.

Title: Re: Lucas E3L - is this the right one?
Post by: chaterlea25 on 30.09. 2011 20:41
Hi Alan,
I would find and fit the correct sprocket
I dont know where the 15 tooth came from? is it the correct pitch for the chain??
If so it may be from a C11???? Bigger 3/8 pitch maybe from a Norton or AJ/Match)
E3L's to the best of my knowledge only come in 2 different types , magdyno and taper shaft
(as in one will fit and one wont *conf*)
The belt drive conversions available speed up the dynamo 10 or 15%
Some people prefer to keep the dynamo standard (6v) and use a12v reg
Others prefer the converted 12v dyno

HTH
John O R
Title: Re: Lucas E3L - is this the right one?
Post by: trevinoz on 01.10. 2011 00:24
Alan,
           You need the 11 tooth sprocket if you are using a chain.
BSA E3L generators used this one. The earlier E3H used a 13 tooth sprocket.
It looks like the bearing retaining plate has been modified for the generator to be fitted to something else so will need to be replaced.

John,
            C11 & C12 used the same generator as the larger models and there is another type or two or so of E3L, viz Triumph, Norton, AMC etc.

  Trev.
Title: Re: Lucas E3L - is this the right one?
Post by: Goldy on 01.10. 2011 16:26
The other thing to check is the direction of rotation. I had an old E3L but is was the wrong direction. There is an arrow marked into the outer casing.
Title: Re: Lucas E3L - is this the right one?
Post by: chaterlea25 on 01.10. 2011 19:12
Hi Goldy,
Getting the dynamo to charge in the opposite direction is easy *smile*
Reverse the field connections!!
HTH
John O R
Title: Re: Lucas E3L - is this the right one?
Post by: 900triple on 01.10. 2011 19:32
Thanks for all of your replies - so...does it look as if I need to replace the drive end plate? If so anyone know of any contacts around who would have/sell one of the correct ends?

Cheers

Alan
Title: Re: Lucas E3L - is this the right one?
Post by: rockthedog on 06.11. 2011 18:32
Hi Goldy,
Getting the dynamo to charge in the opposite direction is easy *smile*
Reverse the field connections!!
HTH
John O R

how do you do that *smile*
Title: Re: Lucas E3L - is this the right one?
Post by: chaterlea25 on 06.11. 2011 19:18
Hi rocket,
When you remove the dynamo end cover you will see two wires coming out of the innards of the dynamo  *eek*
one goes to the "F" connection on the end plate and the other is earthed to the body
Swop the connections around
HTH
John O R
Title: Re: Lucas E3L - is this the right one?
Post by: LJ. on 06.11. 2011 20:06
I would think that a 15 tooth sprocket would make the dynamo spin slower thus outputting lower voltage.