ignition

metal bits

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hi building twin engine to black shadow spec this engine mite go into a norvin or egli
does anybody know which distributor was fitted to the vincent twin and were i can get one
ore does any body know which would be a better ignition system
 

davidd

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If you have the original magneto, assuming it is a C Shadow, you should send it out for a rebuild. You can then run it or put it on the shelf as a spare.

If you have no ignition then you have lots of choices. If I did not know what chassis the motor would be in, I would probably buy a new BT-H. I have had good luck with mine. I would reccomend it because it will fit under the original mag cowl. It is available in single or dual plug versions. It is called a magneto, but it is really a coil ignition system that generates its own power.

There are lots of battery coil electronic ignitions available. Mounting the box and the coils should be a consideration.

There is the Series D distributor. You will have to find a used one or convert and old Triumph distributor. You will need space to mount the coil. This is a good system and it is well known.

Once you decide which direction you think you should go I am sure you will get lots of opinions.

David
 

Jim Richardson

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Price Productions who advertise in the back of MPH were selling distributor kits, but I think it has been mentioned on the forum recently that he has run out.

JimR
 

metal bits

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if i buy a triumph distributor what sort of mods have i got to make have i got to alter cam profile ore just make a new cam
 

john998

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Hello, You need a new cam and a distributor that is clockwise drive. Triumphs are anticlock. Not sure but only Enfields and Vincent are clock wise drive.
Regards John.
 

timetraveller

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I remember speaking to someone years ago who told me that he had converted one rotational type of distributor to the other and it had meant removig the advance/retard weights and turning them over, or possibly even more of a mod. I have never tried it but if someone out there has an old 'wrong' style distributor it might be worth having a look It will certainly be necessary to modify the cam, even if the trick with the weights works.
 

stumpy lord

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Hi,
Their is a good artical in Know they beast regarding fitting a D distributor to a twin in chapter 19 page191. might be worth reading.
 

b'knighted

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My twin runs a modified Ford distributor which, when I got it had, been set up with two sets of points. That way the cam becomes less important as the relationship between spark and piston position is controlled by where the points are mounted rather than the shape of the cam. The cam can easily be converted to single lobe. I assume that the range of advance was set to suit the Vincent engine by restricting the bob weight travel. Potentially easier would be to lock the distributor spindle and drive it with a new ATD.
I replaced the points with a Lumenition Optronics CD system and reintroduced the Ford rotor arm and distributor cap. This has worked well for more than three decades.

For a new system I'd recommend a fixed spindle set up with a solid state retard such as the, now unavailable, Lucas Rita.
I fitted a twin Rita system on a Comet and that would start by hand.

Mistral Engineering have developed its successor, called the MOIRA which will work with the old trigger system. It'll give give full power sparks from 60rpm to 20,000 sparks per minute (should be enough for all except Vibrac). It incorporates a shutoff facility to turn it off if inactive for six seconds but switch back on once triggered saving us from flat batteries or burnt out coils. Standard it is 12v negative earth.
 

b'knighted

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As I didn't steal it from the car I don't actually know its origin, but I am sure it was a standard 4 cylinder. What twins did they make? It has a triangular flange fitted to bolt on as per mag, and its shaft has an adapter to take an ATD pinion. Its bob weights retard it to a point which makes for easy starting and it doesn't pink as I time it at full advance. As it starts well I assume that the range of advance is about right. It was originally built for use on a highly tuned Shadow probably running five star petrol so I'm surprised that its range isn't too much.
The guy who built it to convert his bike to coils bought his bike in 1958 and reverted to standard 30 years later so guessing the age of the donor vehicle is difficult. I suspect it was 100e or 105e era. His evil Shadow was timed at 135 in third. I think I understand why he softened it once he was into his forties.
I use a 4 cylinder distributor cap with two opposite pickups cut out and replaced with plastic numberplate bolts. The tip of the rotor arm has been replaced with a longer contact area to compensate for the uneven firing of the vee twin. The cap and rotor arm were done in the seventies and I really wish I knew what model they were intended to fit as I would quite like to have spares on the shelf. If my Lumenition system (bought in about '72, for a tweaked Morris Minor) fails I will go the MOIRA route.
 
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