DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
By using this site, you agree to our rules. Please see: Terms of Use
DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
My motorcyclist friends have suggested rather than looking at complete electronic ignition, try an Inductive Discharge Unit, such as fitted to a lot of motorcycles. Apparently, very easy to fit into the existing electrical circuit. Gives reduced sparking at the points and as such an extended points life, no timing worries, improved combustion and sometimes better mpg.
I have found such a device at Boyer Brandsen who have been around for many years and guarantees the unit for 5 years.
Has anyone any practical experience of these units or advice?
I have found such a device at Boyer Brandsen who have been around for many years and guarantees the unit for 5 years.
Has anyone any practical experience of these units or advice?
-
- Minor Maniac
- Posts: 10816
- Joined: Thu Jul 19, 2012 12:05 pm
- Location: Hampshire
- MMOC Member: Yes
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
https://en.wikipedia.org/wiki/Inductive ... e_ignition
I personally would not spend the money. Points if looked after work well and are reliable.
Only if having a performance engine would I consider changing to another type of ignition system.
I have a full Luminition electronic ignition system fitted to my minor and that works well. Before that I had a Cooper S distributer fitted with Cooper S points and never had any problem even at high revs.
I personally would not spend the money. Points if looked after work well and are reliable.
Only if having a performance engine would I consider changing to another type of ignition system.
I have a full Luminition electronic ignition system fitted to my minor and that works well. Before that I had a Cooper S distributer fitted with Cooper S points and never had any problem even at high revs.
Last edited by philthehill on Tue Jul 06, 2021 10:40 am, edited 1 time in total.
- geoberni
- Minor Legend
- Posts: 3597
- Joined: Fri Aug 04, 2017 11:19 am
- Location: North Leicestershire
- MMOC Member: Yes
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
Such Electronic Units as you speak of were a bit of a fad at the time, offering all the things that are currently listed on the Boyer Bransden website, "Points life is extended beyond 30,000 miles and more energy reaches the spark plug for improved combustion and m.p.g."
However I don't think you've looked well enough if all you've found is the Boyer unit, which by their own admission "are intended primarily for motorcycle use."
The unit I used on my Escort, for the couple of years I had it, was a Sparkrite Unit, the latest version of which is readily available.
From the looks of it, externally it's essentially the same thing, except the 1975 version was painted bright orange instead of grey.
The SX4000 is a plain little box presumably designed to be unobtrusive, my SX2000 was a bit more in your face, letting people know you had the latest gadget.... Did it do what it was supposed to, I really can't remember, but I know it never failed on me.
The Boyer units look to be around £100, the Sparkrite are designed for cars and are around £25-£30
I see no mention of it on the Boyer Unit, but the current Sparkrite model, the SX4000 has the same feature my SX2000 had all those years ago. "In the unlikely event of a malfunction of the electronics, the SX4000 has the reassurance of a bypass mode so you can return to conventional points/condenser operation at the flick of a switch"
https://sparkrite.co.uk/electronic-ignition-kits/
Last edited by geoberni on Tue Jul 06, 2021 11:02 am, edited 1 time in total.
Basil the 1955 series II
-
- Minor Legend
- Posts: 1666
- Joined: Thu May 12, 2016 6:33 am
- MMOC Member: No
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
I built a capacitive discharge electronic ignition system (from a electronics mag circuit) in about 1972, that retained the contact ponts but only used a tiny trigger current.
That worked well on my Ford Escort until the current required exceeded the inverter output (at about 6000rpm).
Up to that point a simple ammeter could be used to measure engine speed.
That system was virtually bomb-proof apart from, perhaps, the spark duration for any ‘cooking’ 4 pot engine.
I believe the inductive electronic systems improved spark duration and became popular later. I also expect the accuspark (and such-like) electronic systems are also inductive types - as they still use a coil to generate the high voltage required for the spark…
In simple terms, you generally ‘pays your money and gets what you pays for’. There are better electronic systems than those fitted by the majority of moggie minor owners, but they are more costly. As I recall, I only needed to flip a (double pole double throw?) switch, fitted to the project box lid, to revert to the Kettering system.
The biggest problem I see, with retaining the contact points is that of contact bounce and dwell period at extremely high rotational speeds. I believe many older multiple-cylinder motorcycles used more than a single contact breaker and coil to reduce dwell angle problems? I expect most, these days, utilise Hall Effect devices, so no points at all.
With no timing worries (as long as it is correct) and improved combustion, I would automatically expect one of either more power or improved economy - the latter only evident if that extra power was not utilised.
Edited to add that clearly others got here before me! And I agree with PTH that the Kettering system is quite adequate for the lowly powered minor engines - but does require some extra simple-enough maintenance.
That worked well on my Ford Escort until the current required exceeded the inverter output (at about 6000rpm).
Up to that point a simple ammeter could be used to measure engine speed.
That system was virtually bomb-proof apart from, perhaps, the spark duration for any ‘cooking’ 4 pot engine.
I believe the inductive electronic systems improved spark duration and became popular later. I also expect the accuspark (and such-like) electronic systems are also inductive types - as they still use a coil to generate the high voltage required for the spark…
In simple terms, you generally ‘pays your money and gets what you pays for’. There are better electronic systems than those fitted by the majority of moggie minor owners, but they are more costly. As I recall, I only needed to flip a (double pole double throw?) switch, fitted to the project box lid, to revert to the Kettering system.
The biggest problem I see, with retaining the contact points is that of contact bounce and dwell period at extremely high rotational speeds. I believe many older multiple-cylinder motorcycles used more than a single contact breaker and coil to reduce dwell angle problems? I expect most, these days, utilise Hall Effect devices, so no points at all.
With no timing worries (as long as it is correct) and improved combustion, I would automatically expect one of either more power or improved economy - the latter only evident if that extra power was not utilised.
Edited to add that clearly others got here before me! And I agree with PTH that the Kettering system is quite adequate for the lowly powered minor engines - but does require some extra simple-enough maintenance.
-
- Minor Legend
- Posts: 1053
- Joined: Tue Nov 08, 2016 3:18 pm
- Location: Manchester ( Damp and Miserable ) and that's just the wife...
- MMOC Member: Yes
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
Sparkrite SX4000 write-up , fourth post down, sheds some light on it
https://autoshite.com/topic/30553-the-n ... page/1479/
John ;-)
https://autoshite.com/topic/30553-the-n ... page/1479/
John ;-)
- geoberni
- Minor Legend
- Posts: 3597
- Joined: Fri Aug 04, 2017 11:19 am
- Location: North Leicestershire
- MMOC Member: Yes
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
That's interesting. Probably a reflection of crappy Chinese workmanship and poor quality control by Sparkrite on the goods they're buying in. Probably be better off getting an older model from ebay... There's a SX1000 listed at the moment....Sleeper wrote: ↑Tue Jul 06, 2021 1:17 pm Sparkrite SX4000 write-up , fourth post down, sheds some light on it
https://autoshite.com/topic/30553-the-n ... page/1479/
John ;-)
Basil the 1955 series II
-
- Minor Fan
- Posts: 469
- Joined: Thu May 11, 2017 8:23 pm
- Location: South Cheshire
- MMOC Member: Yes
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
That just reminded me, in 1975, when the speedo cable broke on my Anglia I knew that I was going at 60 mph because my ammeter was reading 15 amps Happy days.oliver90owner wrote: ↑Tue Jul 06, 2021 11:02 am
Up to that point a simple ammeter could be used to measure engine speed.
-
- Minor Legend
- Posts: 1666
- Joined: Thu May 12, 2016 6:33 am
- MMOC Member: No
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
Dunno how that could be. Do tell us how you could tell, depending on electrical load, battery state of charge and battery condition. At night or in the day? Windscreen wipers operating or not? Heater on?paul 300358 wrote: ↑Tue Jul 06, 2021 4:02 pmThat just reminded me, in 1975, when the speedo cable broke on my Anglia I knew that I was going at 60 mph because my ammeter was reading 15 amps Happy days.oliver90owner wrote: ↑Tue Jul 06, 2021 11:02 am
Up to that point a simple ammeter could be used to measure engine speed.
The capacitive system inverter power draw varied between virtually nowt when the engine was stopped to ~1A at 6000rpm, IIRC. Plus or minus a few percent dependent on the component values. As I recall, I reduced the capacitor value for ‘high speed’ running to avoid exceeding the inverter output at high rpm, but needed to piggy-back an extra capacitor to get the engine started at times. As I recall, the inverter only achieved about 300 volts on the capacitor - but these details are from a long time ago, so a little fuzzy.
-
- Minor Fan
- Posts: 469
- Joined: Thu May 11, 2017 8:23 pm
- Location: South Cheshire
- MMOC Member: Yes
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
It was a standard 105e, the only extra was a smiths ammeter off a Foden lorry. The only thing that I can remember is that with 3 other apprentices in the car, every one watched the ammeter as when we got to charging at 15 amps we were doing about 60mph and everyone cheered.oliver90owner wrote: ↑Tue Jul 06, 2021 10:47 pm Dunno how that could be. Do tell us how you could tell, depending on electrical load, battery state of charge and battery condition. At night or in the day? Windscreen wipers operating or not? Heater on?
One of my mates dad was a motorway traffic policeman, he had a chat with me and a new cable was purchased as soon as possible!!
-
- Minor Legend
- Posts: 1666
- Joined: Thu May 12, 2016 6:33 am
- MMOC Member: No
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
3 other apprentices in the car, every one watched the ammeter as when we got to charging at 15 amps we were doing about 60mph and everyone cheered.
Four apprentices … about 60mph …cheered.
I think we can discard that recollection, without any more consideration, that ammeter readings had anything to do with the speed of the car.
Four apprentices … about 60mph …cheered.
I think we can discard that recollection, without any more consideration, that ammeter readings had anything to do with the speed of the car.
-
- Minor Fan
- Posts: 472
- Joined: Mon Nov 18, 2013 11:07 am
- Location: Oxfordshire
- MMOC Member: No
Re: DISTRIBUTOR INDUCTIVE DISCHARGE UNIT
I have one of the Sparkrite units show further up fitted to one of my Minors. Its stored at my parents so only gets started once every 4 months. If I don't charge the battery then it wont start easily in normal mode. Switch it to Electronic though and it generally starts first time.
Glad to be back!