I'm really just floating a question/idea here. In the 60s and 70s many cars used 6 Volt coils on 12 Volt systems, using a ballast resistor to keep to 6 volts limit on the coil during normal running. But when the car was starting, the ballast resistor was bypassed and a full 12 volts was applied to the 6 volt coil, this gave it a super boost during the period when the starter motor was turning, hence better starting performance.
My question is has anybody ever fitted a 6 Volt coil to an 12 volt alternator model HW single using a ballast resistor to keep the voltage under control during normal running but a boost switch to shovel full 12 volts through the six Volt coil while you're trying to start it, thereby giving a nice fat juicy spark. It worked on cars why not bikes.
12volt bike running with a 6volt coil
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leobailey
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Ralph
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Re: 12volt bike running with a 6volt coil
I think it was more to do with countering the voltage drop when the starter was engaged.
Ralph
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leobailey
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Re: 12volt bike running with a 6volt coil
Yes I fully appreciate that point, if your car battery was not a full par when you went to start the car it, then grinding away on the starter motor would only make things worse, the voltage to the coil would be down from the ideal, but the use of a ballast resistor and 6 volt coil got around that problem.
That is fact I owned several Fords fitted with that system I also believe Vauxhall used it.
No you missed my point. I would be using the system to simply to boost the coil voltage over it’s normal running voltage for five seconds (hopefully) that it takes to get the beast to fire up. A simple push button to bypass the Ballast resistor.
A good coil should give a good spark, a momentarily boosted coil will give you a better spark.
In the early 1980’s I owned a Ford Cortina it had done 130,000 miles plus and was getting quite difficult to start some times. The wiring in the car was getting quite jaded and so I installed a second 12 Volt battery in the boot protected by a diode and ran and new 12 Volt line to a switch on the dash and on forward to the existing coil.
The car of course had a ballast resistor in the wiring loom, I was bypassing that completely with a guaranteed good 12 Volt kick up the backside from the battery in the boot which only fed that circuit. So when it wouldn't start, I simply pressed the button and tried again and hay presto, it started.
That is fact I owned several Fords fitted with that system I also believe Vauxhall used it.
No you missed my point. I would be using the system to simply to boost the coil voltage over it’s normal running voltage for five seconds (hopefully) that it takes to get the beast to fire up. A simple push button to bypass the Ballast resistor.
A good coil should give a good spark, a momentarily boosted coil will give you a better spark.
In the early 1980’s I owned a Ford Cortina it had done 130,000 miles plus and was getting quite difficult to start some times. The wiring in the car was getting quite jaded and so I installed a second 12 Volt battery in the boot protected by a diode and ran and new 12 Volt line to a switch on the dash and on forward to the existing coil.
The car of course had a ballast resistor in the wiring loom, I was bypassing that completely with a guaranteed good 12 Volt kick up the backside from the battery in the boot which only fed that circuit. So when it wouldn't start, I simply pressed the button and tried again and hay presto, it started.