Misc: Ignition Twin Points Ignition

[Pushrod Twin]

I recently took a wild punt and liberated, out of Florida via Fleabay, the points ignition pictured. It is rather well made. However, I have a bunch of questions regarding it's origin and history.
For some reason there are fasteners missing, as was advertised. I pondered which side of the Atlantic it may have been made on so set about to identify the threads in the hope of working that out. Both the 3/16 threads which retain the drive gear, & the 5/16 threads in the adaptor were coarse, could be either BSW or UNC, however, the 2 holes for the missing screws intended to retain the points plate to the body are 3/16 BSF. Not necessarily 100% conclusive, but does lean towards being British.
Then the underside of the points plate clearly indicates the origin of that component at least.
Is this the points plate fitted to the Lucas twin points devices used on Norton & AMC twins in the 'late '60's?
The auto advance mechanism is small & tidy, but the shaft is way too long to be from the aforementioned AMC/Norton device and it all appears to be one piece. The shaft is ground and runs in Oilite bushes. No Git seal on the shaft,but a nicely made labyrinth which fits into the crankcase bore and mounts the drive gear. This clearly achieved the aim, there was no evidence of oil having flooded the shaft cavity, nor wear on the shaft or bushes. The external condition indicates that this device has has done some solid service.
Does anyone recognise it? Is it a one off, or did someone attempt to make a batch?
On a more technical note, what coils & condensers would Mr Lucas recommend to be matched with these points?

 

[timetraveller]

There used to be a firm in the English midlands called Dolphin Motors who made something similar. I do not have a photograph of their system so cannot be sure it is one of theirs. If it is they worked well enough but had a reputation for it being difficult to keep the timing fixed as the points tended to slip. It is possible that these days with Loctite or something similar they could be made to work. As for what coils and condenser well remember that these are only points so the rest of the system can be 6 or 12 volts and I would just go through a catalogue of what coils were used on single cylinder bikes. Same with the condensers. Personally I have not found either the coil of condenser to be overly critical on Vins but there are probably others on here who are more competent than me concerning such matters.

 

[Bill Thomas]

As long as the coil is for Points !, Electronic ignition coils have a different ohms rating.

 

[Pushrod Twin]

There used to be a firm in the English midlands called Dolphin Motors who made something similar. I do not have a photograph of their system so cannot be sure it is one of theirs. If it is they worked well enough but had a reputation for it being difficult to keep the timing fixed as the points tended to slip. It is possible that these days with Loctite or something similar they could be made to work. As for what coils and condenser well remember that these are only points so the rest of the system can be 6 or 12 volts and I would just go through a catalogue of what coils were used on single cylinder bikes. Same with the condensers. Personally I have not found either the coil of condenser to be overly critical on Vins but there are probably others on here who are more competent than me concerning such matters.

Thank you. I am pretty confident that it is not a Dolphin. Research here on the Forum brings up pictures that show the Dophin with points assembly on the outside of the timing cover.
I know from years of ownership of of other points operated bike ignitions that we could get away with fitting random coils and condensers to keep them going. Then reading the manuals for those bikes, the manufacturer gives specific resistance figures for the coils and capacitance figures for the condensers & I wondered if there is a match to give the optimum points life?

 

[Bill Thomas]

Why not use the "D" distributor Condenser,
But I think any old car one would do,
I think Big Sid said use one off an old Honda Bike ?.

There is a photo of the Dolphin ignition on my old racer , Under rose joints today !.

 

[Bill Thomas]

Sorry , Twin points you will need 2 small condensers,
What about Commando ones.

 

[stu spalding]

It's OK to run two sets of points connected together along with a single condenser and a single lobe cam. He Who Knows Electrics told me that it's OK to adjust the timing between the cylinders by varying the points gaps, as long as they're fairly close to start with. I run twin plug heads with two twin lead coils. Modern condensers don't seem to last as well as old ones. Cheers, Stu.

 

[Marcus Bowden]

I have two Raps with a Grosset ignition system, it is just an electronic trigger unit that doesn't need condensers and will fire two twin double coils for twin plugging arrangement or just one but you require less advance if twin plugged so I incorporated a manual advance/retard lever. The auto advance is mechanical similar to Lucas distributor or have the the auto advance reduced by Francios, the beauty with the system it uses very little current and I've run for two days on a charged battery only all indicators LED of cause. No messing with points as it's not so easy nowadays up & down on ones knees. One other thing I fitted were two little switches so I can switch on or off each coil in turn as you run 10 degrees retarded about if a coil fails the bikes still goes as normal but now too retarded, I drop a valve seat on the front exhaust and holed a piston in the rear by 20 mm simultaneously ! 2010 at 60 MPH. on the rebuild i put the coils one to each cylinder doesn't work too well, ask the boffins they explained it was because the way the coils are wound.
Like air craft twin ignition systems so test periodically when traveling. Your in your own cockpit.
bananaman.

 

[Monkeypants]

My OZ Rapide has a similar ignition. The housing is quite different in shape.
My ignition uses ignition points, twin condensors, twin 6 Volt coils and ballast resistor all from a Norton Commando.
It's important to use only new old stock Lucas points. The Japanese Daichi replacements are junk.
New old stock Lucas points are getting hard to find. I'll bet there are still some in the UK at the Autojumbles.
I recently bought some ignition points on eBay. These were listed as new old stock original Lucas points. They ad listed the correct Lucas part number. The points were in an orange box labeled " Lucas"
But inside were the junk Daichi points.
With proper Lucas points installed you can ignore the ignition for at least 30,000 miles.
The dual point dual coil ignition gives very easy starting.
One other note - my system requires a fairly wide point gap, no closer than 20 thousandths.
I set it at 25 thou.
At 18 thou or less it will only fire one cylinder.
Your system may have a differently shaped points cam which would change things.

Glen

 

[BigEd]

My OZ Rapide has a similar ignition. The housing is quite different in shape. .....
..........
One other note - my system requires a fairly wide point gap, no closer than 20 thousandths.
I set it at 25 thou.
At 18 thou or less it will only fire one cylinder.
Your system may have a differently shaped points cam which would change things.

Glen

Is that a dwell angle problem? With so many vehicles using electronic ignition these days we forget about some of the things we had to look out for when using points.