Magneto base clamp between top of case and base of magneto?

[Tourist]

Good evening all,

What style of base clamp are you supposed to use with a Vertex magneto on a late T1/2/3 crankcase?

Is there any reason why you should not use a clamp intended for a normal distributor?

Any help appreciated ,
Martin.

[Jon]

The clamp doesn't need to be special, but a support of some kind is "needed".

[Tourist]

Thankyou Jon

Only reason I ask, is all the cars/engines I have looked at recently with magnetos fitted, have had base clamps where the pinch bolt is horizontal with the crank pulley like this:
http://www.thesamba.com/vw/classifieds/detail.php?id=1449846

rather than vertical with the centreline/joint in the crankcase like this: http://www.thesamba.com/vw/classifieds/detail.php?id=1187193

I wondered whether there was a reason for it, for example access for adjustment etc. due to the physical size of a magneto

I have a magneto which I need to find a clamp for, but don't want to buy a regular one if it means I will have hassle getting to the pinch bolt....

Martin.

[WPS]

Hey Martin

It's all a matter of making sure the mag seats into the dizzy drive enough....but not too much so as to loose all the drive end float.If you use the standard distributor clamp on some mags it will pull the base of the mag out of the drive ( by the thickness of the clamp) and risk not seating properly which can raise two problems 1.the dizzy drive will chatter as the end float of the drive is massively increased and will damage the brass gear (why most people blame mags for damaging gears) and 2.the mag drive key can slip out of the drive and damage both and of course your timing/engine!
There's is a special clamp for mags that vw made for the industrial engine which goes around the base of the mag without being sandwiched between the mag and the case but I've also used mags that require a standard vw dizzy clamp so the only way to be sure is to measure everything i.e. the length of mag verses the dizzy you're removing.
Of course the best way is to fit it and set the end float (with the factory shims) on the drizzy drive before you drop the crank in when building the engine.....this is always the first job I do when assembling any motor and make sure the clamp etc is all flat with no gaps to the case...like the cheapo chrome ones! How you set the dizzy drive endfloat accurately with the case already assembled is a mystery but people still do it!
Mags are usually loose in the case so a support bracket is advisable which can double as a clamp aswell but again check the mag is not bottoming out on the drive /brass gear or both will wear prematurely and make sure the support is tight enough to stop the mag from rotating and altering your timing as some/most aftermarket supports will do up tight but not really clamp/hold the mag tight enough so mods are required.......other than that it's easy!!  Enjoy they're worth it.......

Ian

[WPS]

Pictures of VW 'mag' clamp along with two different mags end to end showing the difference in length.
The long one takes the standard dizzy clamp, the short one needs the 'mag' clamp.
Maybe this makes it clearer....

Ian

[Lee.C]

And this is exactly why I came to you buddy 

[jay c]

i had a bit of trouble finding a clamp so i had a go at making one by cutting some 3mm steel plate to shape and welding a tube to it.Then cut through the tube.On the case i had to fit a longer stud and use a spacer.Seems to work ok [ Attachment: You are not allowed to view attachments ]

[Tourist]

Thankyou Ian, your second post made things much clearer



If I have read your post correctly, it looks like I will need the magneto-specific clamp- cue another parts quest....lol

jay c: That looks pretty neat.

Martin.