Ignition coil primary circuit power, ballast or no ballast???
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- čas přidán 22. 07. 2024
- There seems to be a trend in the uk with Classic miniowners either fitting the incorrect coil or removing the ballast resistor system altogether, a backward step, here is why………
I always understood a ballast resistor was to help cold start and a sports coil was the way to go, but a temperature sensitive ballast resistor is a performance enhancement, as the rpm increases, relatively the coil output does too! Great stuff
Thanks for that. Its about time someone pointed out the advantages of retaining a ballast ignition arrangement. I have just been dealing with an MGB that a previous owner had fitted a 3 Ohm Lucas Sports coil to (without removing the ballast resistor). The result was very poor cold starting and this has been resolved by installing the correct coil. I am not too concerned about more power at higher engine speeds so I probably won't bother to try by-passing the ballast resistor but thanks for the suggestion.
The suggestion is only for those in competition really where any small gain is beneficial. In any account I would actually test that on a dyno first to see if it did offer an advantage as some specifications I suspect it won’t.
Thank you for this. I thought the primary reason for a ballast resistor circuit was to improve cold starting. I did not realise there was also a benefit when running at higher RPMs.
That’s the point, people don’t realise the science of why these things are actually done in the first place.
When systems went from 6v to 12v the ballast resistor was added because the coil and points were unchanged. The bypass of the ballast on start (extra tab on the solenoid) gives a bit more kick for a cold start. Once you are no longer cranking the resistor isn't bypassed and the voltage is dropped so you don't heat up the coil with too many volts at lower RPMs. Some coils have 3 or a bit more ohms of resistance. They don't require the ballast resistor.
thnks ac
Really interesting, I’ve recently tested my coil, as I’m not sure what one it is, it’s 1.5 ohm on a 65dm4 distributor, reading your comments on the forums, I think this is ok
Running a Lucas DLB101 Ignition Coil
A standard 12v ignition coil from Lucas(silver).
On a MG metro 1275 with a D59 (electronic point's) and Stealth 8mm heavy duty stainless steel wire wound HT leads.
Primary resistance 3.0 Ohms.
Says its perfect for use with a electronic ignition kit.
Plug gap 3.0 thou.
Starts on the key and runs well cold or hot.
Maybe if you tried a ballast setup you may notice an improvement.
@@ACDodd 1.5 ballast resistor/1.5ohm coil before.
ballast vs. non-ballast
One of the most confusing items I came across was the uncertainty of whether I had a ballast or a non-ballast coil and what that really meant. I think it's important to understand that these two coils are designed for different ignition systems. A ballasted system is designed so the coil's normal operating voltage is around 6-9 volts and a non-ballasted system is designed to operate around 12 volts. This may have nothing to do with the voltage in the rest of your car's charging system, so don't think that just because your battery outputs 12 volts, you have a non-ballasted coil. The type of ignition system determines the resistance of the coil you should be using. A non-ballasted coil should be 3 ohms and a ballasted coil should be 1.5 ohms.
why are there two?
Ballasted ignition systems were designed to accommodate a wide range of operating conditions. A 3 ohm coil can only produce it's power when it is being supplied the necessary 12 volts. This means that in cold cranking situations when the batteries voltage dropped, the coil wasn't receiving enough power to create a spark.
On the flip side, there is the 1.5 ohm coil which is happy to operate in these lower voltage scenarios. Unfortuantely, they would burn out quickly if operated constantly at 12 volts. The solution to this problem was the ballast which reduces the voltage down to the 6-9 volts the 1.5 ohm coil prefers. It isn't, however, just that simple. In order to maximize the coil's output during starting, ballasted ignitions have a ballast bypass which sends 12 volts directly to the coil during startup. This doesn't create any issues for the ballast because the jump wire now creates 12 volts on both sides of the resistor. There is no longer a current flow, so the resistor doesn't do anything.
Want a change
Maybe you might want to switch because you are running an electronic distributor which needs 12 volts or you are trying to get the most out of your sport coil. Whatever the reason, the process to change from a ballasted system to a non-ballasted system seems fairly straight forward. It requires replacing your 1.5ohm coil (assuming you hadn't already installed the wrong coil) with a 3 ohm coil, and providing the 3 ohm coil with 12 volts.
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An ignition system with breaker points will surely suffer from reduced point life if the ballast resistor is removed, as higher amperage can damage the surface of the points causing failure. Additionally, if the ignition is left in the run position and the points happen to be open-or worse, barely open-electrical arcs can cause raised spots on the points resulting in a change in dwell timing or an engine that won't run at all.
Electronic ignition systems, whether factory or aftermarket, don't utilize breaker points, thereby not actually needing a ballast resistor to control amperage through the pickup coil. And while ignition coil life may be compromised without a resistor, the additional secondary voltage (at the spark plug) is increased which generally improves power. So does your application require a ballast resistor? Quite simply, if your distributor has breaker points the answer is yes; if not, the answer is no.
Points need a ballast resistor and so do electronic systems which have a fixed dwell angle. If you by pass the ballast resistor at high rpm and full power operation the effect on points life reduction is minimal as the engine won’t be in that condition all the time. Secondly the reduction in coil charge time brought about by the increased rpm goes some way to offset the current flow. By passing the ballast altogether will result in burned points and overheated coil as you mentioned.
I appreciate your video, thank you. I imagine your wattage values come from measuring the amperage draw & voltage? There might be a flaw in this method because an ignition coil has to ramp up the amperage draw. I think we need to see an oscilloscope comparison of the amperage draw between the 2 coils to really understand.
There may be a difference, the point is the engine runs better with a system when the power supplied to the ignition circuit is higher, based on my experiences.
Very interesting. The ballast resistance can also be a length of resistance wire in the loom instead of an individual resistor. It might be prudent to mention electronic systems and what coils they require. The Lucas 64D4 electronic system apparently needs about a 0.9 ohm coil, whereas the aftermarket units for fitting to points distributors seem to need at least 1.5 ohm coils. I'm not sure if there are any other OEM electronic units on minis..
Lucas 65DM4 takes a factory 0.8ohm coil and uses no ballast feed. Instead the 65d is a variable dwell angle unit which reduces the dwell at lower rpms and increases at higher rpms, thus increasing the coil power as the rpm rises
@@ACDodd SPi Minis have electronic ignition which is controlled by the ECU. They use a ballast coil arrangement.
@@grahamwoodier5066 no, they use the same 0.8ohm coil arrangement as the 65DM4 units. No ballast is used.
Remember The point of a Ballast resistor, is as the load changes, as the heat changes. Probably not very efficient with a single resistor wire. Only benefit will be cold start, not stronger spark, increasing RPM?
This is brilliant. Thanks AC! Can and should I use a ballast resistor with electronic ignition or is that purely for a points distributor?
Watch the other videos on electronic ignition for the answer
This change has been made at some point to my mini - presumably when the electronic ignition was fitted. I'd thought about switching back to a ballast setup but have been unsure if a ballast setup suitable for use with electronic ignition.
Depends what type you have
@@ACDodd it's a powerspark I believe.
@@MattJonesBedwas remove the dizzy cap and take a
Picture of the module
@@ACDodd I can't post a picture on here. I checked with the previous owner - my cousin - and he fitted the "Powerspark electronic Kit 45D distributor Mini (K4 & R2)" kit. He said he was running with a ballast coil but replaced it after a year or so with non ballast coil. I've had a look at the cables and the White and Pink ballast cable and the White and Yellow cables are still there taped up so it should be easy enough to switch back. Would it be worth it?
@@MattJonesBedwas lifted from the powerspark website
Powerspark Electronic Ignition Kits are designed to work with a coil resistance above 1.5 ohms, typically 3.0 ohms. Some performance coils operate at a lower resistance and will need the High Energy electronic ignition kit.
In this case yes a 1.5 ohm coils would work.
I would simply up grade to a high power unit, and fit the 59d dizzy with the high power module and run a 0.8ohm coil, these units feature variable dwell angle and do away with the ballast feed and you can run big sparks.
Is there any way that the ballast resistor can be progressively phased out as the rpm rises say beyond 4000rpm. Thus potentially giving a much bigger/more powerful spark progressively up to maximum rpm?
Micro switch on the throttle, shorts the resistor out only when maximum power is required
It does, as the load on the rpm increases
I am no expert, just wondering if measuring wattage is a good indicator of spark energy? Measuring the average amperage draw, is like measuring fuel consumption and inferring top speed or horsepower.
The current flowing though the coil when the points open is the important number, because that indicates the energy stored in the magnetic field of the coil when the spark is needed. Also, it's a square law, the energy stored in an inductor is proportional to current squared,
Could you do a video and explain why ignition coils get hot and start breaking down or causing misfires? Thanks
I do think
That needs a video, that’s down to coil type and application
@@ACDodd had this problem with my Range Rover as well, used a 3 ohm coil instead of a 0,8 ohm that should be used.....
very...how do I wire a ballast in a Essex v6 engine using electronic ignition..please
You don’t, use a variable dwell ignition kit and then use a low ohm high power coil
My Mini has a Pertronix Ignitor II electronic ignition with a Flame Thrower 0.6 Ohm coil Their instructions state to run it without any ballast resistor. Why is this recommended?
Because the unit is likely variable dwell, this means at idle the coil is being under utilised and at full rpm full power is available
What’s the best coil to use with the old sparkrite sx2000 electronic conversion box?
The standard 3 ohm unit.
Thanks
Is the coil resistance you're taking about just measured across with with a multi meter?
Across the terminals yes
@@ACDodd Thanks, I'll have a measure.
...amazing setup! Big thumbs up. A question : as I understand it electronic ignition does not require a ballast, but if a ballast wire is present (and using a 1.5 ohm coil) is there any reason not to keep the ballast system in place if using electronic ignition? - are there any bad side effects, or is it just a case of it makes no difference?.
I ask this, as while the dizzy is now using electronic ignition, I'm tempted to go back to points - as performance seemed more lively ...but would like to keep the ballast and coil constant rather than swapping coils and bypassing / including the ballast wire etc.
Nothing wrong with keeping the ballast system with electronic ignition (even if it doesn't require it)?
Is your electronic system variable dwell?
A drop in Powerspark module.
@@juliansimmons7700check it with a dwell meter
@@ACDodd ...I need to get one! As an all-round automotive multimeter which would you suggest under £100. The Draper DMM301 looks ok?
Engine is 6 cylinder.
I think a 1.5 ohm coil with a 1.5 ohm ballast wire (or 1.4 ohm coil with a 1.6 ohm ballast wire, or thereabouts) means the EI module would be fine. Only on cranking (when the ballast is bypassed) might it potentially receive a higher voltage - though the starter motor might push it down.
In anycase, I'm thinking based on your tests I might go back to points (& keeping the ballast), for the extra spark power at higher revs - or would that also be true with EI?
@@juliansimmons7700 no, using electronic ignition with variable dwell and a low ohm coil gives you more power at high rpm than using points with 1.5ohm coil and a ballast.
The ballast resistor isn't shorted out, should say it is bypassed. Also, notice the big blue glow on the drill press/pillar drill table, that's you points arcing & going through hell.. Lucas condenser POS mismatch to your coils. Wonder why Lucas points needed replacement so often?
It’s not my view or experience.