Mag Coil Conversion

[Charles P]

Having tired of recent magneto issues I decided that a mag coil conversion would be a better bet, since I can at least trouble shoot the components of a coil system, whereas replacing components in a magneto is much harder.
So I made one (as you do) using a Bosch 009 distributor, the end plate of a discarded dynamo and turning the central shaft from a broken half shaft. I’ve just bolted it on and it appears to work ok. I dare say that a Bosch 009 of indeterminate heritage (almost certainly not European) may cause a problem at some point but at least I can have spare points/cap/rotor/condenser easily and inexpensively to hand. 

What’s the best way to wire a coil system into a Lucas SM3 switch panel? I may want to return to a magneto in the future. I’m thinking of simply connecting the coil feed to the dynamo switch position but is there another solution.

Thanks

   


Charles

[Colin Morgan]

Some coil conversions are better than others.  This one came back from the US on a 1928 Chummy - the belt drive was neither precise nor robust and the distributor turned the wrong way so the auto advance did not work. 


  Chummy_Coil_Conversion.jpg (Size: 249.5 KB / Downloads: 356)

It had a separate switch - the original wiring hadn't been altered which made it easy when swapping back to a magneto.

[Alan]

I’ve an original Lucas coil conversion which I use when the mag isn’t working (quite often at times) I don’t use the switch panel - feed is through a separate switch. Means that you have to switch the dynamo on separately but that’s ok. All the magneto wiring is still there and you can change mag to coil in minutes.

[leaf200]

Nice looking conversation. What gears did you use

[Charles P]

Nice looking conversation. What gears did you use

Thanks
A pair of Remax ones that I bought off David Barker

[Dirk73]

Thanks
A pair of Remax ones that I bought off David Barker

A very neat job. Those gears aren't the same ratio as normal dizzy drive gears then? (i'd always assumed the dynamo ran faster than engine speed on a coil engine)

[Charles P]

Thanks
A pair of Remax ones that I bought off David Barker

A very neat job. Those gears aren't the same ratio as normal dizzy drive gears then? (i'd always assumed the dynamo ran faster than engine speed on a coil engine)

Correct. Austin 7 dynamo/distributor gears don’t run on a simple 2:1 ratio because they have to compensate for the cam/dynamo ratio. That’s why you need an alternative set

C

[leaf200]

Do you know what car your remax ones were off?

[Charles P]

Do you know what car your remax ones were off?

Sorry, no 

C