Misc: Ignition Electronic Ignition Vs B.T.H Magneto Replacement

[Lucas Magneto]

Hi all,
need help trying to identify ignition system fitted to my 1951 Rapide. that I am currently recommissioning. This bike has not run since 1981,so I expect that this is most likely 70*s wizardry. It has an optical trigger and a home made actuating shield (see pics), looks to me like some kind of CDI black box of a type of I've not seen before and using single nippon denso twin lead coil to fire the plugs.
The unit appears to work when wired up and tested statically, however the spark wasnt what i would call fat blue crack, more of a slightly weak blue with a tinge of yellow ! I was wondering if it is worth going down the route of trying to get it refurbished or more likely replace with a more modern unit.
I have had experience of the self generating BTH mag in KTF format on two Tritons one excellent and one bad, a ceased bearing spinning in the housing after one season, puts me off a bit now.
I run a Trispark on my T150 Trident and found it to be excellent and so easy to set up but there are others out there that claim to be just as good or better for Pazon for example, however, I only have experience of these on parallel twins that don't have the same characteristics of 50 deg Vtwin. As all of these options are not particularly cheap, I would like to hear some of your experiences or recommendations with any of the above systems to help me decide which way to go

regards

 

[IRBrock]

Hi all,
need help trying to identify ignition system fitted to my 1951 Rapide. that I am currently recommissioning. This bike has not run since 1981,so I expect that this is most likely 70*s wizardry. It has an optical trigger and a home made actuating shield (see pics), looks to me like some kind of CDI black box of a type of I've not seen before and using single nippon denso twin lead coil to fire the plugs.
The unit appears to work when wired up and tested statically, however the spark wasnt what i would call fat blue crack, more of a slightly weak blue with a tinge of yellow ! I was wondering if it is worth going down the route of trying to get it refurbished or more likely replace with a more modern unit.
I have had experience of the self generating BTH mag in KTF format on two Tritons one excellent and one bad, a ceased bearing spinning in the housing after one season, puts me off a bit now.
I run a Trispark on my T150 Trident and found it to be excellent and so easy to set up but there are others out there that claim to be just as good or better for Pazon for example, however, I only have experience of these on parallel twins that don't have the same characteristics of 50 deg Vtwin. As all of these options are not particularly cheap, I would like to hear some of your experiences or recommendations with any of the above systems to help me decide which way to go

regardsView attachment 56683View attachment 56684View attachment 56685

I have Trispark on a Rapide. Very satisfied. Ian.

 

[Chris Launders]

I have no experience of electronic ignition except for I run a modern BTH on my twin. but you mention the possible difference between a parallel and V twin, once you have moved away from a traditional magneto this is irrelevant, it is only the physical limitations of a "proper" magneto that causes problems.
I seem to remember there was an optical ignition called Lumenition like that, they are still in business.

 

[timetraveller]

I used Lumenition in my Range Rover for years as the points used to wear out every year with eight cylinder to feed and doing 40,000 miles a year. It was very good for years but then I was in the South of France and it started fail. I got all the way back to within fifty yards of my home before it finally packed up. I broke down in front of a neighbours house and he refused to tow me the final fifty yards as my car was 'so big', I finally got it home by using the starter motor in gear. Points might wear out but at least one can change them.

 

[vibrac]

After many years of racing a single on a BTH and latterly a twin I think a BTH is perfectly capable for road use there is some question of its low speed spark for kick starting but seeing some methods of kickstarting a twin I think thats mainly down to leg technique.
We run a Top of the range programable tri spark unit tuned on a dyno for our goodwood racer but it takes a sophisticated coil ignition to beat a BTH
I have a BTH on the E start Comet its nice to know that failure of electrics and battery wont stop me getting home BTH is fit and forget.

 

[ericg]

I have Trispark on a Rapide. Very satisfied. Ian.

The Trispark's advance range is only 12°5, so 25° at the crank. What full advance figure did you use?

 

[ClassicBiker]

Looks like an early version of the XR700 by Crane. I've had a Lucas Rita on my Shadow and currently have a BTH on it. The Rita worked fine, the only reason I swapped was it sucked up the electrons. Between it and the quartz halogen headlight the Alton could not keep up. Now they are independent of each other and the Alton has an easier time of it. The Comet is fitted with a Boyer Bransden system which seems to not seem so addicted to electrons. I'm considering getting a BTH for the Comet to separate the systems. I'm also considering refurbishing the K1F for this.
On my 60s and 70s Triumphs I have both Lucas Rita and Boyer Bransden, both have been reliable and I'm glad I swapped to them. But I think the capacity of the 3 phase, 180 watt RM24 alternators I've fitted play a large part in this as they provide their maximum power at fairly low rpm. There are posts on this forum point out that the speed of the dynamo/Alton arrange is less than engine speed. I'm not convinced the Alton provides enough as I live in a fairly built up area and low engine speeds are the order of the day. Incidentally I have a Crane system fitted to my MG B, and that takes a moment or two after startup for the charge light to go out. I think you would be better served by either getting a newer system that doesn't use a lot of current or a BTH.
Steven

 

[vibrac]

The Trispark's advance range is only 12°5, so 25° at the crank. What full advance figure did you use?

We used the Fire box pro racing system not the road standard system it had a rev limiter as well and a dragable advance curve

 

[ericg]

We used the Fire box pro racing system not the road standard system it had a rev limiter as well and a dragable advance curve

Thanks Tim but the question was for IRBrock. I noticed you said "programable Trispark" in #5.

 

[danno]

I've had a Lucas Rita on my Shadow and currently have a BTH on it. The Rita worked fine, the only reason I swapped was it sucked up the electrons. Between it and the quartz halogen headlight the Alton could not keep up. Now they are independent of each other and the Alton has an easier time of it. The Comet is fitted with a Boyer Bransden system which seems to not seem so addicted to electrons. I'm considering getting a BTH for the Comet to separate the systems.

I have a Lucas Rita on my 1952 Rapide and is much as you describe.
I don’t get a lot of charge due to it being quite power hungry but it gives a good spark on startup. Did consider a BTH
when I swapped out the Miller dynamo/JG converter arrangement for an Alton.
I did look for a Boyer Bransden system but couldn’t see one listed on their site for a twin.