vh charging

[DaveWatson]

Has anyone fitted an alternator to a vh (I don't have a magdyno)

[nevhunter]

They never had anything but a magdyno as far as I know. They (magdyno's) are still about. Many british bikes fitted the alternator on the engine driveshaft, later models 56 +. The ARIEL set up doesn't really suit that arrangement. If you run a coil you need a 1/2 speed set of contacts with advance/retard, or a CDI trigger mechanism with 'Wall" effect for advance programming. Personally I hate having to have a "reliable" battery for ignition. With a magneto you just give it a kick in the Guts and it goes if they are done right. Nev

[DaveWatson]

Thanks I guess I will just have to bite the bullet and get a magdyno

[nevhunter]

They are the achille's heel of the post war singles, where used, but I don't get much problem with the magneto part if the chain doesn't overtighten and the armature can be pulled out of true as (typical LUCAS) it only has 2 screws holding the armature in alignment. I persist with the standard generator and regulator because I have gotten used to them. The acid leaking batteries drive me nuts, and I'm still looking for a good PASTE Gel Battery (6V). Nev

[Bob.Murphy]

There are some interesting conversions about in the Club. People put car-type Alternators on, fit a timing pick-up to the back and run an electronic coil ignition system off it:















Pictures taken at the 2013 Scottish "Cuddy" Rally.

A few have done this (Lew Wallwork's name comes to mind) and they may be able to provide the details.

Bob.

[nevhunter]

Driving the points off the same shaft limits the speed of rotation of the alternator to twice engine speed (with a dead spark) You can get away with it but there's a chance of a backfire when flooded so a some sort of spark arrestor on the intake might be a good thing, otherwise it's engine speed and the output is quite limited at those RPM. I've fitted smaller alternators on Light aircraft engines, so there's definite possibilities. Chain or gear drive to a generator or alternator is harder on them than a vee or toothed belt drive.. With a gear it's desirable to have a rubber section in the coupling. You could get your triggering for the spark from a magnet fixed in the flywheel Again there you would have a spark each revolution. Nev

[john.mitchell]

Club member Tony Harris recently sold this company. They make new magnetos ...
http://www.bt-h.biz/bt-h-magnetos-5-c.asp

[DaveWatson]

The car type alternator is what I had in mind if anyone can give me details of mod I would be very grateful
Thanks all

[nevhunter]

The small Toyota's and perhaps other similar have the most compact readily available. Also used on the smaller Jap. fork lifts. Cheap at wreckers. You can cut and weld the end pieces for a mount platform. I understand a Kawasaki one has been suitable. They get fitted to U/L aircraft so need similar small and light features. The most suitable drive is a belt for reliability and longevity of the unit. Chains and gears transmit all the shocks . There's a fair bit of mass in the rotor. Nev

[DaveWatson]

Thanks that's a great help
dave w