Lucas Magneto Coupling Mystery

Id use a strip of rubber sheet pushed into the space .........Incidentally,if you dismantle the mag to grease the bearings ,be sure to remove any safety gap screws before taking the armature out............these will often break a piece out of the slip ring.

The obvious thing is to make a simple bracket in 30 minutes and put on a cheap 4 cylinder distributor and coil. I would like to keep it original.

On the Peking to Paris all the cars went through lots of magnetos. It would seem around 5,000km time before failure running them all day every day. The usual point adjustment and burn out was expected but the big problem was the tiny ball bearing races giving it away. The 5 cars had different brands of magneto and all gave problems and had to be rebuilt or one made out of three along the way.

Three of the cars finished with the magneto bypassed and a coil and condenser wired in just using the points and distributor from the magneto. The little bearings had become so sloppy the armature was touching the magnets killing the spark.

This would be the bee's knees. I reckon I could build a bracket and drive in under an hour never to worry about spark again.

 

This may be of some use in the future.

www.mg-cars.org.uk/news/news243.html

I have almost nil experience with magnetos, I did have a Ingersol Rand lend lease compressor,  it ran a American Bosch magneto with a 4 cyl.  engine... the magneto had a automatic mechanical  spark retard mechanism for hand cranking, I never got it running. 

 

Magnetos mostly are nor too hard to sort out. Coils, condensors n caps n leads. Magnetism at times does need a boost but not all that often

Not hard...but expensive if the coil is kaput ......some have rewound the coil themselves ,but with around 8,000 turns of .004 wire ,and paper every layer ,it would get tedious .........its a shame the common Lucas SR 4 mags dont have a manual advance ,that would simplify things.

Yes Magneto rebuilds cost $500-$800.

All vehicle magnetos had manual advance. I think the fixed ones were just for stationary engines running inside a tight rev band.

As I said I have several magnetos of different brands in working order that would be an easy fit but just trying to stay true with the Lucas GA4.

I've had to replace 4 coils in the past. Lucas RS1 coils were $80 each plus post n that was not on an exchange basis. 

The wound armature magnetos are generally $400-$500 to get rewound etc.......a good check of the coil is how hard it is .....if its soft and pushes in ,its no good ......it may spark ,but will fail when it gets hot............The armature type put out a much hotter spark at cranking speed than the rotating magnet SR s and RS ,and Wico s ......generally the rotating magnet ones have an impulse coupling to give a starting spark.