CONFUSION: 123Ignition: WRONG replacement rotor arm - 123 vs points.
The short answer - Sellers are supplying the wrong rotor arm - rotor-arm resistance is 5kΩ.
Many don't seem to understand ignition. I suspect this is rooted in the utter BS marketing used by sellers to shift ignition-coils and classic ignition in general as high-power.
If it's 3Ω it can't be a high-power coil. The laws of Physics and Ohm's Law makes high-power impossible... I'll cover coil-power, vacuum and variable-dwell too. Running them straight from the pack - thus not coil-power matched - too many won't gap their classic's plugs.
We have to accept, electronic ignition for the beard-brigade amongst us, is a controversial subject. Many think electronic sparks is done to remove points, this grasps only half the story. The "It starts, it works” dictum prevails. The real reason worries few.
Now this'd be where your average Yank has us beat.
With 8-pots as near enough the US standard, thus double the sparks at the same rpm, you don't get the BS seen amongst our standard 4 & 6 pot Euro classic owner brethren. The US knowledge-base on dwell(coil charge time) and thus coil-power is more universal, simply because at much over 4-5000rpm the reality gets rammed up the Jacksy of your actual Yank until he does.
Be aware, running a ballast resistor with 123 rather self-defeats fitting 123 in the first place. You're usually better with a 1.2Ω coil, and no ballast. Many more of you will install plugs straight from the packet.
Sadly it''s a rare thing, yet carbed and sparked right, a properly set-up classic, more so a 4-pot Series LR is a joy to behold. It's a shame, yet owners seem to prefer the standard bodge Zenith and dizzy from Dizzy Doc... this at best.
Yup... The same could be said of many classics.
Near all classics suffer the same faults. Few seem to grasp, factory-fresh vehicles in the 1950s to the 80s were made to drive a coach and horses through the tolerances. More to minimise warranty claims than to produce best power or economy. This means they weren't best new. They didn't start on a cold morning or stay in tune. The blunt truth is, and there's a heap of evidence to show this - few were ' in tune ' on the showroom floor.. Back when, The last nth of labour was costly, buyers knew no different and today's classic owners follow.
Many owners insist on fitting ballasts and 3Ω coils. That’s just how it was, and still is. Factor in worn carbs, tired coils and dizzys and it won't look good.
However… read your choice of classic-car forum and you soon get the impression ignition and fuel-metering is not widely understood. This despite the ease of doing so. Seldom will you find proper set-ups. Most won't have ways to measure either.
Anyways, owners of other marques seem to have greater grasp of what 123Ignition and electronic ignition in general truly does. Alfa and Mini owners in particular. Spot on timing, with variable dwell allows for high-power coils which light-up weaker mixtures. This post is more likely to be picked up by our MG, Triumph, A-Series, Jag owning brethren. Your can run 1.2Ω coils with 123. No ballast. Even 123Ignition don't push this, and for clear 'box-shifter' rmotives. If you understand ignition you can't say you can blame them.
There's no good reason your classic can't run ignition power with large spark-plug gaps to match. A set-up more akin to an early 90s set-up than any 60s or 70s ballast/3Ω system. Lighting-up weaker mixtures gives driveability at low rpm and a whiff of throttle in ways you'll not see with any 60s set-up. But... its necessary to understand how and why. Most don't - most want a plug-play solution.
123Ignition Rotor arm & distributor caps:
Albertronic the makers of 123Ignition, are understandably mildly hazy on their consumerables. Fair enough - as the manufacturer of 123Ignition, they want us to buy replacement rotor-arms & distributor caps from them. Why would they not?
All 123Ignition 4-cyl & 6-cyl distributors use the same rotor arm. These are supplied to Albertronic by Beru.
The four-pot distributor cap is easy - you want:
Beru VK 105 (Fits all - slide index tab to fit late type 123Ignition)
Beru VK106 (will not fit early 123Ignition)
Beru VK334 angle (will not fit early 123Ignition)
There's s a metal sliding index tab on the side of 123 distributors. Move as appropriate.
www.sparkplugs.co.uk
CONFUSION: 123Ignition: WRONG replacement rotor arm - 123 vs points.
CONFUSION: 123Ignition: WRONG replacement rotor arm - 123 vs points.
Last edited by fuckwit on Wed Jul 29, 2026 2:11 pm, edited 82 times in total.
Re: 123Ignition: replacement rotor arm & distributor cap confusion.
I have no experience of the six-pot versions of 123Ignition. 123 6-pot caps are easy enough Beru VK102 (I think?) ... the problem sits with the arms.
The four and six-pot rotor arm
Albertronic do supply Bosch equiv. numbers, thing is, you’ll find these lead to a part number dead-end. Albertronic quote the rotor as: Bosch 1 234 332 024. This is unobtainium. The best you’ll get is the Bosch later equiv. Bosch 1 234 332 088.
Thing is, Bosch 1 234 332 088 comes up large on the spindle; thus the rotor-arm swings in the breeze. Seems, all the sellers are at it, few will sell you anything but a Bosch or Bosch clone. You’re met with actual false ‘this rotor fits 123’ claims.
Sellers will sell you their version of Bosch 04008 (superceeded by 1 234 332 088).
Whilst Bosch 1 234 332 088 will fit, er, kinda… not really.
The principal eBay seller for iffy 123Ignition rotor-arms is the one outfit that ‘might’ know better… SimonBBC must have seen more dizzy, caps and rotors than pretty much the rest of us put together?
These arms will fit, the Bosch rotor-arms will fit, just not well. It'll flop on the spindle.
You're looking for the rotor arm for the rotor arm for:
1956-65 Porsche 356
1954-1965 1.2L VW Beetle/Bus/Ghia (2-piece points).
1960-1972 Mercedes W108 (with cast iron distributor).
Problem is, ask for such a things and you're back to a Bosch 04008 (superceeded by 1 234 332 088).
OK then...
You want the Beru original. And here's why....
A1: (See the area marked Blue ). There's a step/ narrowing to the spindle on 123Ignition distributors.
B1: (See the area marked Red ). The cut-out / clocking lug is wider than most.
The effect of A1 - SimonBBC's rotor-arm (and the others inc. Bosch) are found too wide, thus have play - they'll wobble on the 123Ignition spindle.
The effect of B1 - This has the rotor rotate roughly 5 degs - which if you've in a timing-light session anyway will be accounted for, and if you've not (very possible?) this will throw the timing. The wobble you'll see gave mine very spotty timing. It was this sudden 5-6 degs timing-difference which brought the whole rotor thing to my attention.
REMEMBER: Your DIZZY runs HALF the speed of your CRANK. Thus one or two degrees of slop at your rotor arm gets DOUBLED at the CRANK.
The four and six-pot rotor arm
Albertronic do supply Bosch equiv. numbers, thing is, you’ll find these lead to a part number dead-end. Albertronic quote the rotor as: Bosch 1 234 332 024. This is unobtainium. The best you’ll get is the Bosch later equiv. Bosch 1 234 332 088.
Thing is, Bosch 1 234 332 088 comes up large on the spindle; thus the rotor-arm swings in the breeze. Seems, all the sellers are at it, few will sell you anything but a Bosch or Bosch clone. You’re met with actual false ‘this rotor fits 123’ claims.
Sellers will sell you their version of Bosch 04008 (superceeded by 1 234 332 088).
Whilst Bosch 1 234 332 088 will fit, er, kinda… not really.
The principal eBay seller for iffy 123Ignition rotor-arms is the one outfit that ‘might’ know better… SimonBBC must have seen more dizzy, caps and rotors than pretty much the rest of us put together?
These arms will fit, the Bosch rotor-arms will fit, just not well. It'll flop on the spindle.
You're looking for the rotor arm for the rotor arm for:
1956-65 Porsche 356
1954-1965 1.2L VW Beetle/Bus/Ghia (2-piece points).
1960-1972 Mercedes W108 (with cast iron distributor).
Problem is, ask for such a things and you're back to a Bosch 04008 (superceeded by 1 234 332 088).
OK then...
You want the Beru original. And here's why....
A1: (See the area marked Blue ). There's a step/ narrowing to the spindle on 123Ignition distributors.
B1: (See the area marked Red ). The cut-out / clocking lug is wider than most.
The effect of A1 - SimonBBC's rotor-arm (and the others inc. Bosch) are found too wide, thus have play - they'll wobble on the 123Ignition spindle.
The effect of B1 - This has the rotor rotate roughly 5 degs - which if you've in a timing-light session anyway will be accounted for, and if you've not (very possible?) this will throw the timing. The wobble you'll see gave mine very spotty timing. It was this sudden 5-6 degs timing-difference which brought the whole rotor thing to my attention.
REMEMBER: Your DIZZY runs HALF the speed of your CRANK. Thus one or two degrees of slop at your rotor arm gets DOUBLED at the CRANK.
Last edited by fuckwit on Sun Nov 30, 2025 1:29 pm, edited 31 times in total.
Re: 123Ignition: replacement rotor arm & distributor cap confusion.
If you do follow the Bosch 1 234 332 024 trail to its end, you'll finish with Bosch later equiv. Bosch 1 234 332 088. Note the parrallel bore. See above.
Which is not so different to what you get from one eBay seller. Note the parrallel bore. See above.
Problem is, what came as original fit on your 123Ignition is a Beru, and a Beru looks like this. See above.
Note: the narrowing and the step in the vertical. Matches step on the 123Ignition spindle.
Note: not so clear in pic, the 'clocking lug' is wider to correspond to the lug in the 123Ignition spindle. This clocks your arm to the spindle.
Note: the chord on the circle.
Sellers
Speak to sellers about the dubious fit, and you'll be told they've sold hundreds like this without issue? Yours truly is forced to admit, the idea that hundreds of classic-car owners buy any old shonk... and STILL... yes stilll won't notice is VERY believable.
When your customer is a fool... read the internet forums on the subject for proof.
Says here, fits 123. See it swing in the breeze.
I'll be blunt, set in the line-up at your local fete/ car-show - poseurs to a man, most flat refuse to drive much over 300 miles a year. Why would they notice?
Which is not so different to what you get from one eBay seller. Note the parrallel bore. See above.
Problem is, what came as original fit on your 123Ignition is a Beru, and a Beru looks like this. See above.
Note: the narrowing and the step in the vertical. Matches step on the 123Ignition spindle.
Note: not so clear in pic, the 'clocking lug' is wider to correspond to the lug in the 123Ignition spindle. This clocks your arm to the spindle.
Note: the chord on the circle.
Sellers
Speak to sellers about the dubious fit, and you'll be told they've sold hundreds like this without issue? Yours truly is forced to admit, the idea that hundreds of classic-car owners buy any old shonk... and STILL... yes stilll won't notice is VERY believable.
When your customer is a fool... read the internet forums on the subject for proof.
Says here, fits 123. See it swing in the breeze.
I'll be blunt, set in the line-up at your local fete/ car-show - poseurs to a man, most flat refuse to drive much over 300 miles a year. Why would they notice?
Last edited by fuckwit on Thu Apr 16, 2026 8:58 am, edited 45 times in total.
Re: 123Ignition: replacement rotor arm & distributor cap confusion.
Next.... Beru et al.
Here's the kiddy. See the part number. I picked these up for £5-6 each. Bought three.
www.sparkplugs.co.uk
Paid about what you'd pay for one proper Beru any where else.
Note the step in the bore, and the chord / / half-moon tooling which clocks the arm to the spindle.
Compare. That pic of BOSCH 1 234 332 088 again. Sale Ends Soon.
Mind, this is a lost cause. Beru insist their equiv. is BOSCH 1 234 332 088. It isn't.
Here's the kiddy. See the part number. I picked these up for £5-6 each. Bought three.
www.sparkplugs.co.uk
Paid about what you'd pay for one proper Beru any where else.
Note the step in the bore, and the chord / / half-moon tooling which clocks the arm to the spindle.
Compare. That pic of BOSCH 1 234 332 088 again. Sale Ends Soon.
Mind, this is a lost cause. Beru insist their equiv. is BOSCH 1 234 332 088. It isn't.
Last edited by fuckwit on Thu Sep 18, 2025 9:37 am, edited 12 times in total.
Re: 123Ignition: replacement rotor arm & distributor cap confusion.
BOSCH 1 234 332 088 versus Beru. This pic courtesy of others discussing the same issue.
Some are thinking. "Will one be enough?"
However if you're desperate, only not ^^beyond hope^^: I found Intermotor 47110S - It's lug is wide - whilst well short of perfect - it will move timing 5ish degrees - it's the best stop-gap.
The Beru original arm
In mass production, BERU EVL4/6-Z has the tooling we require. Last seen standard-fit on Porsche 356; some 60s Volvos and Merc W108. There can't be too many 60s Volvos and Mercs, still sporting their original dizzy? And a Porsche 356?? This rotor must be pretty obcscure.
As said, the four-pot cap comes easier. I found if I sourced a cap for a Porsche 924, a Beru. Your mileage may vary.
Resistance
As supplied the BERU EVL4/6-Z has 5kΩ. Some of you want 0Ω. Beru NV017 is 0Ω with the correct tooling, thus identical without resistor. Good luck sourcing those.
You're looking for the rotor arm for the rotor arm for:
1956-65 Porsche 356
1954-1965 1.2L VW Beetle/Bus/Ghia (2-piece points).
1960-1972 Mercedes W108 (with cast iron distributor).
Problem is, and we repeat, ask for such a things and you're back to a Bosch 04008 (superceeded by 1 234 332 088). These are 5KΩ and don't fit.
Seems any rotor arm at 0Ω is pretty rare. You're making your own. There's stuff if you search, showing people digging out the resistor and soldering solid copper/brass - this into stock BERU EVL4/6-Z arms.
There's a Yank seller putting out low 0.2Ω arms with correct fit too.
https://123ignitionusa.com/rotor-for-al ... esistance/
I gather required for CD ignition. MSD etc. Repeated high voltage spikes from multi-spark CD ignitions mean the stock resistor rotors fail.
Some are thinking. "Will one be enough?"
However if you're desperate, only not ^^beyond hope^^: I found Intermotor 47110S - It's lug is wide - whilst well short of perfect - it will move timing 5ish degrees - it's the best stop-gap.
The Beru original arm
In mass production, BERU EVL4/6-Z has the tooling we require. Last seen standard-fit on Porsche 356; some 60s Volvos and Merc W108. There can't be too many 60s Volvos and Mercs, still sporting their original dizzy? And a Porsche 356?? This rotor must be pretty obcscure.
As said, the four-pot cap comes easier. I found if I sourced a cap for a Porsche 924, a Beru. Your mileage may vary.
Resistance
As supplied the BERU EVL4/6-Z has 5kΩ. Some of you want 0Ω. Beru NV017 is 0Ω with the correct tooling, thus identical without resistor. Good luck sourcing those.
You're looking for the rotor arm for the rotor arm for:
1956-65 Porsche 356
1954-1965 1.2L VW Beetle/Bus/Ghia (2-piece points).
1960-1972 Mercedes W108 (with cast iron distributor).
Problem is, and we repeat, ask for such a things and you're back to a Bosch 04008 (superceeded by 1 234 332 088). These are 5KΩ and don't fit.
Seems any rotor arm at 0Ω is pretty rare. You're making your own. There's stuff if you search, showing people digging out the resistor and soldering solid copper/brass - this into stock BERU EVL4/6-Z arms.
There's a Yank seller putting out low 0.2Ω arms with correct fit too.
https://123ignitionusa.com/rotor-for-al ... esistance/
I gather required for CD ignition. MSD etc. Repeated high voltage spikes from multi-spark CD ignitions mean the stock resistor rotors fail.
Last edited by fuckwit on Thu Apr 16, 2026 9:15 am, edited 10 times in total.
Re: 123Ignition: replacement rotor arm & distributor cap + resistance confusion.
This saga has the makings of a PR own-goal for Albertronic
Set-up correctly 123Ignition is a brilliant product. Wobbling rotor-arms in Albertronic's product can't be good long-term. The rotor-arm sellers just box-shift. They don't seem to know what they sell is wrong; buyers don't notice. Suspect the reason it's not gone bent so far is; the vast majority of users are poseurs - on their first rotor-arm. Ever less seem to truly understand ignition or the real reasons for electronic-sparks in the first.
Two useful mods:
1) Get yourself a waterproof cover.
Sold to the Beach-buggy crowd - I got myself a VW cover. If any MGB B-Series owners are reading this, you know all about leaking heater tap drain-valves not mixing with 123. A VW 'shower-cap' is essential.
2) Solder in a TVS Diode [1.5KE18CA] as shown.
They're under £0.30p each, yet with postage and min.quantities you'll probably finish with a dozen and pay a fiverish. It'll protect your pricey 123Ignition if there's ever an over-voltage from an iffy alternator or similar. Only the twin-curve variant of 123 has the yellow wire.
Note use of the proper earthing on the dizzy body, there's threading for it - focus on decent earths with electronics - very important you use this. This is the usual reason you'll hear failure complaints with electronic-ignition conversions. Most half-arse this.
Don't.
Shrink-wrap & solder. With dubious earthing it's a copper-bottom guarantee voltages around a dizzy will go somewhere. The hassle - and your wallet - won't like where.
Thus when you read the words... "I'm going back to points... "; "You can't fix it in the field"
The rough translation is: "I won't be told... I talk out of my rectum... blah... and I'm an ocean-going c*nt".
Ahem, solder. Modern electronics won that battle some 30-40 years back.
Coil-power & plug-gaps
Getting rid of points is not the sole reason for the move to electronics. Coil-power plays the larger part. Be clear, there's nothing wrong with a 3Ω coil yet understand the limit with points. Points won't control more than 3Ω thus you're limited to low-power 3Ω coils (a 1930s/40s/50s/60s set-up) or 1.5Ω + 1.5Ω ballast (a late 1960s/70s/early 80s set-up). Either way 3Ω total. Fixed-dwell.
Classics were fitted with this set-up because without electronics that's the only way it could be done. Of course it'll run - it's not wrong - just don't expect to light-up lean mixes, and see max-driveability. That'd be one reason why low-compression ratios were the thing. Electronics controls dwell, and consistent coil charge-times. That's important. Points if they could run low-resistance coils would have dwell for too long. Be switched on for too long. This would overheat the coil and burn out the points. Electronics goes round this issue.
Variable Dwell
Aside from timing stability the greater advantage of electronic-sparks is variable dwell. Dwell is the charge time for the coil. It’s higher (or more correctly longer in time) at low revs. Variable dwell allows low Ω coils. Less than 1 ohm on electronic ignition and I know of systems with 0.5 ohms.
Low resistance means the current is high. Points won’t handle this. With no limit on the time the coil gets to charge - the dwell - even if points could, overheats at low revs.
Electronic-sparks is about chasing full coil saturation at high revs while limiting current and heating at low revs - thus increasing spark energy. Variable dwell.
Spark energy is proportional to the coil inductance x the primary current squared. More current has a big effect and offsets lower inductance. Lower primary resistance lowers inductance and this allows the coil to charge faster . Bigger sparks, better burns. This is the objective, particularly on six and above cylinder engines.
Understand, run rich and it's easy. Any coil / plug-gap combination will run fine. This is not wrong, rich is easy to light-up. In the 'points era' lack of coil-power by running rich is how it was done. Rich burns faster too, thus if the mixture control is out, it wouldn't matter. Rich doesn't require so much use of vacuum advance either. Back when fuel was cheap, the solution was simple - use more fuel. More fuel bore-washes too. Only bore-wash is another discussion.
VACUUM
It's also why vacuum advance is removed from race-engines. They're run rich & flat-out anyway, no requirement for vacuum. Vacuum is road-car stuff, vacuum adds driveability and economy at part throttle. Because you're not filling cylinders at cruise you should be running lean/weak at lower revs. The weaker mixture needs more time and coil-power to light-up. That'd be what vacuum achieves. Many do, yet anyone removing vacuum from a road-car 'because race-car' doesn't understand what vacuum does.
Dwell is the time given by your distributor to charge the coil. Electronics allows control of this. Variable-dwell is achieved via current control in modern ignitions. This means we can run low resistance/ high power coils. 0.8Ω and often far less. These low-resistance coils take less time to charge, and variable-dwell is how this is done. With more coil-power we are getting wider plug gaps. Thus we light-up weaker mixtures. That'd be why today's plugs are supplied at 35-40 thou (1.1mm) gap. Plug manufacturers assume we run the coil-power for wider gaps.
You don't. You run a classic. When your classic was new, plugs came pre-gapped for classics. No more. Unless you've a modern coil to match, you're required to gap down. Today's plugs will run in a classic and still come pre-gapped. Only gaps that wide is not for you.
One gripe.
I'd like to run 0.8Ω coil or less as modern practice, which is a gripe with 123. A 123 is variable dwell yet won't handle 0.8Ω. However we can't blame Albertronic for this. If 123 did run lower Ω coils they'd be mis-wired and Albertronic would see a heap of recalls from the "I refuse to use solder, 123 is no good" cohort. Search the web and there's enough people complaining about 123 now. The 16 pre-set variant seems to get stick from those that don't truly understand it. Modern cars run stoich or lean on over-run and cruise. Establish proper mixture control. The control over timing and vacuum advance 123 gives becomes a great tool.
Like many classics, Land rovers are famous for sub-standard carbs.
Worse still, most will be worn. The faithful will say they've "Had no problems', when sadly even rebuilt Zeniths won't stand scrutiny. Shove a wideband on any Series fitted with a stock carb - rebuilt or not - and the truth is quite shocking. I've not seen one that won't run rich just off cruise and near bore-wash on over-run. That's just how it was done, and without any method to measure it, few were any wiser. Most classics are the same. Engines were well past best by 70-80,000 miles and poor mixture control / bore-wash was part of that.
If like me you run something like an HIF44 ORFCO SU you've control over acceleration/cruise and over-run. The tool-set 123 provides is great. In my case I have a HIF44 SU from an Austin Montego. You'll need a wideband gauge to see what's happening. Cruise is 0.98 Lambda, over-run 1.4, and WOT 0.88.
Incidentally, the ORFCO fuel-cut on over-run is a 1980s addition to the SU. I'd argue it's the ultimate development of the SU. It's not far off what can be achieved via injection.
https://www.youtube.com/watch?v=fjCPoTMeWHE
(See ORFCO cut-off about 17:00 minutes in)
I run an HIF44 [BCQ Needle/ Yellow Spring/ slow-drop damper LZX 1773 SAE50]
The SAE50 and slow-drop damper LZX 1773 is a large part of how this was achieved.
Coil 1.2Ω NGK U1056
No flat-spots, no stench of fuel, a properly set-up classic is a joy to use. It was usual for cars in that era to run well-enough fresh out of the factory, yet not be 'strictly right'. Low-power 3Ω coils fueled engines as 'rich'... limited by points... that's just how it was.
Fuel was cheap. Poor starting in February was usual. It was the Japanese who first started used proper ignition as a standard-fit.
Be minded, modern ethanol fuels are harder to light and slower burning. Ethanol wants more advance and coil-power to light-up. A 3Ω will still work if rich, it just won't be optimal. And with the water found in modern fuels, buy some fuel stabiliser. If you're leaving it over winter, suggest you use Stabil Storage or 360 for a daily.
Coil power
123 speak of using a coil at not less than 1Ω. In practice their own coil comes in at 1.2Ω. It's a rebadged NGK U1056. 123 will run a NGK U1056 without ballast. 3Ω and 1.5Ω ballast set-ups are not really wrong yet if you running weak enough, a 1.2Ω coil without ballast will make a big difference. Of course if you're running bore-wash rich anyway, you'll not notice an improvement. As said, anything will light up 'rich'.
Set-up correctly 123Ignition is a brilliant product. Wobbling rotor-arms in Albertronic's product can't be good long-term. The rotor-arm sellers just box-shift. They don't seem to know what they sell is wrong; buyers don't notice. Suspect the reason it's not gone bent so far is; the vast majority of users are poseurs - on their first rotor-arm. Ever less seem to truly understand ignition or the real reasons for electronic-sparks in the first.
Two useful mods:
1) Get yourself a waterproof cover.
Sold to the Beach-buggy crowd - I got myself a VW cover. If any MGB B-Series owners are reading this, you know all about leaking heater tap drain-valves not mixing with 123. A VW 'shower-cap' is essential.
2) Solder in a TVS Diode [1.5KE18CA] as shown.
They're under £0.30p each, yet with postage and min.quantities you'll probably finish with a dozen and pay a fiverish. It'll protect your pricey 123Ignition if there's ever an over-voltage from an iffy alternator or similar. Only the twin-curve variant of 123 has the yellow wire.
Note use of the proper earthing on the dizzy body, there's threading for it - focus on decent earths with electronics - very important you use this. This is the usual reason you'll hear failure complaints with electronic-ignition conversions. Most half-arse this.
Don't.
Shrink-wrap & solder. With dubious earthing it's a copper-bottom guarantee voltages around a dizzy will go somewhere. The hassle - and your wallet - won't like where.
Thus when you read the words... "I'm going back to points... "; "You can't fix it in the field"
The rough translation is: "I won't be told... I talk out of my rectum... blah... and I'm an ocean-going c*nt".
Ahem, solder. Modern electronics won that battle some 30-40 years back.
Coil-power & plug-gaps
Getting rid of points is not the sole reason for the move to electronics. Coil-power plays the larger part. Be clear, there's nothing wrong with a 3Ω coil yet understand the limit with points. Points won't control more than 3Ω thus you're limited to low-power 3Ω coils (a 1930s/40s/50s/60s set-up) or 1.5Ω + 1.5Ω ballast (a late 1960s/70s/early 80s set-up). Either way 3Ω total. Fixed-dwell.
Classics were fitted with this set-up because without electronics that's the only way it could be done. Of course it'll run - it's not wrong - just don't expect to light-up lean mixes, and see max-driveability. That'd be one reason why low-compression ratios were the thing. Electronics controls dwell, and consistent coil charge-times. That's important. Points if they could run low-resistance coils would have dwell for too long. Be switched on for too long. This would overheat the coil and burn out the points. Electronics goes round this issue.
Variable Dwell
Aside from timing stability the greater advantage of electronic-sparks is variable dwell. Dwell is the charge time for the coil. It’s higher (or more correctly longer in time) at low revs. Variable dwell allows low Ω coils. Less than 1 ohm on electronic ignition and I know of systems with 0.5 ohms.
Low resistance means the current is high. Points won’t handle this. With no limit on the time the coil gets to charge - the dwell - even if points could, overheats at low revs.
Electronic-sparks is about chasing full coil saturation at high revs while limiting current and heating at low revs - thus increasing spark energy. Variable dwell.
Spark energy is proportional to the coil inductance x the primary current squared. More current has a big effect and offsets lower inductance. Lower primary resistance lowers inductance and this allows the coil to charge faster . Bigger sparks, better burns. This is the objective, particularly on six and above cylinder engines.
Understand, run rich and it's easy. Any coil / plug-gap combination will run fine. This is not wrong, rich is easy to light-up. In the 'points era' lack of coil-power by running rich is how it was done. Rich burns faster too, thus if the mixture control is out, it wouldn't matter. Rich doesn't require so much use of vacuum advance either. Back when fuel was cheap, the solution was simple - use more fuel. More fuel bore-washes too. Only bore-wash is another discussion.
VACUUM
It's also why vacuum advance is removed from race-engines. They're run rich & flat-out anyway, no requirement for vacuum. Vacuum is road-car stuff, vacuum adds driveability and economy at part throttle. Because you're not filling cylinders at cruise you should be running lean/weak at lower revs. The weaker mixture needs more time and coil-power to light-up. That'd be what vacuum achieves. Many do, yet anyone removing vacuum from a road-car 'because race-car' doesn't understand what vacuum does.
Dwell is the time given by your distributor to charge the coil. Electronics allows control of this. Variable-dwell is achieved via current control in modern ignitions. This means we can run low resistance/ high power coils. 0.8Ω and often far less. These low-resistance coils take less time to charge, and variable-dwell is how this is done. With more coil-power we are getting wider plug gaps. Thus we light-up weaker mixtures. That'd be why today's plugs are supplied at 35-40 thou (1.1mm) gap. Plug manufacturers assume we run the coil-power for wider gaps.
You don't. You run a classic. When your classic was new, plugs came pre-gapped for classics. No more. Unless you've a modern coil to match, you're required to gap down. Today's plugs will run in a classic and still come pre-gapped. Only gaps that wide is not for you.
One gripe.
I'd like to run 0.8Ω coil or less as modern practice, which is a gripe with 123. A 123 is variable dwell yet won't handle 0.8Ω. However we can't blame Albertronic for this. If 123 did run lower Ω coils they'd be mis-wired and Albertronic would see a heap of recalls from the "I refuse to use solder, 123 is no good" cohort. Search the web and there's enough people complaining about 123 now. The 16 pre-set variant seems to get stick from those that don't truly understand it. Modern cars run stoich or lean on over-run and cruise. Establish proper mixture control. The control over timing and vacuum advance 123 gives becomes a great tool.
Like many classics, Land rovers are famous for sub-standard carbs.
Worse still, most will be worn. The faithful will say they've "Had no problems', when sadly even rebuilt Zeniths won't stand scrutiny. Shove a wideband on any Series fitted with a stock carb - rebuilt or not - and the truth is quite shocking. I've not seen one that won't run rich just off cruise and near bore-wash on over-run. That's just how it was done, and without any method to measure it, few were any wiser. Most classics are the same. Engines were well past best by 70-80,000 miles and poor mixture control / bore-wash was part of that.
If like me you run something like an HIF44 ORFCO SU you've control over acceleration/cruise and over-run. The tool-set 123 provides is great. In my case I have a HIF44 SU from an Austin Montego. You'll need a wideband gauge to see what's happening. Cruise is 0.98 Lambda, over-run 1.4, and WOT 0.88.
Incidentally, the ORFCO fuel-cut on over-run is a 1980s addition to the SU. I'd argue it's the ultimate development of the SU. It's not far off what can be achieved via injection.
https://www.youtube.com/watch?v=fjCPoTMeWHE
(See ORFCO cut-off about 17:00 minutes in)
I run an HIF44 [BCQ Needle/ Yellow Spring/ slow-drop damper LZX 1773 SAE50]
The SAE50 and slow-drop damper LZX 1773 is a large part of how this was achieved.
Coil 1.2Ω NGK U1056
No flat-spots, no stench of fuel, a properly set-up classic is a joy to use. It was usual for cars in that era to run well-enough fresh out of the factory, yet not be 'strictly right'. Low-power 3Ω coils fueled engines as 'rich'... limited by points... that's just how it was.
Fuel was cheap. Poor starting in February was usual. It was the Japanese who first started used proper ignition as a standard-fit.
Be minded, modern ethanol fuels are harder to light and slower burning. Ethanol wants more advance and coil-power to light-up. A 3Ω will still work if rich, it just won't be optimal. And with the water found in modern fuels, buy some fuel stabiliser. If you're leaving it over winter, suggest you use Stabil Storage or 360 for a daily.
Coil power
123 speak of using a coil at not less than 1Ω. In practice their own coil comes in at 1.2Ω. It's a rebadged NGK U1056. 123 will run a NGK U1056 without ballast. 3Ω and 1.5Ω ballast set-ups are not really wrong yet if you running weak enough, a 1.2Ω coil without ballast will make a big difference. Of course if you're running bore-wash rich anyway, you'll not notice an improvement. As said, anything will light up 'rich'.
Last edited by fuckwit on Thu Apr 16, 2026 10:00 am, edited 19 times in total.
Re: 123Ignition: replacement rotor arm & distributor cap + resistance confusion.
HT Leads & Gaps
If your plugs are left at 35thou any 1.2Ω coil (like a NGK U1056) will struggle to light-up weak/lean mixes on cruise, or over-run Gap those plugs down. I run non-resistive NGK BP5E - 25 thou gap plugs, however non-resistive NGK BP6E may be better for many of you.
I use Powerspark 8mm carbon leads - changed yearly.
Keep your leads short too.
Now you have a better grasp of ignition-power, don't get caught by coil-marketing BS...
Many sellers of coils are at it. Instead of coil resistance, they'll use meaningless words like 'Sports' and 'High Performance'. This preys on how buyers understand ignition. Simple Ohms law exposes the lie.
https://ohmslawcalculator.com/ohms-law-calculator
See the current drawn with the resistance values. 11.3 vs 4.53 Amps. Over double the coil power - that's a vast difference.
Ohm's Law in school -
Your spotty 13-14YO self did Ohms Law in school. If the total load on your ignition is 2.5-3Ω, high-power performance ignition is impossible.
The words 'Ballast coil' or '3Ω' and 'Sports etc is a contradiction. In short select coils by resistance. Run as low as your set-up will allow.
Genuine German Made Bosch Blue Coil
A fool's errand. I wouldn't mind only...
The anal-retentives fight to pay ££££££s daft for a 'Genuine German Made Bosch Blue Coil'. It'd be a 3Ω coil anyhow. They clearly don't grasp what they are buying. There's reason modern cars have low Ω coils. Coil-power is King...
If your plugs are left at 35thou any 1.2Ω coil (like a NGK U1056) will struggle to light-up weak/lean mixes on cruise, or over-run Gap those plugs down. I run non-resistive NGK BP5E - 25 thou gap plugs, however non-resistive NGK BP6E may be better for many of you.
I use Powerspark 8mm carbon leads - changed yearly.
Keep your leads short too.
Now you have a better grasp of ignition-power, don't get caught by coil-marketing BS...
Many sellers of coils are at it. Instead of coil resistance, they'll use meaningless words like 'Sports' and 'High Performance'. This preys on how buyers understand ignition. Simple Ohms law exposes the lie.
https://ohmslawcalculator.com/ohms-law-calculator
See the current drawn with the resistance values. 11.3 vs 4.53 Amps. Over double the coil power - that's a vast difference.
Ohm's Law in school -
Your spotty 13-14YO self did Ohms Law in school. If the total load on your ignition is 2.5-3Ω, high-power performance ignition is impossible.
The words 'Ballast coil' or '3Ω' and 'Sports etc is a contradiction. In short select coils by resistance. Run as low as your set-up will allow.
Genuine German Made Bosch Blue Coil
A fool's errand. I wouldn't mind only...
The anal-retentives fight to pay ££££££s daft for a 'Genuine German Made Bosch Blue Coil'. It'd be a 3Ω coil anyhow. They clearly don't grasp what they are buying. There's reason modern cars have low Ω coils. Coil-power is King...
Re: 123Ignition: replacement rotor arm & distributor cap vs points confusion.
A dizzy will always be the weak-point.
Be minded as the energy from each spark leaves the coil its hobbled via two lengths of HT lead and the jump across the gap twixt rotor-arm and cap.
For radio suppression reasons amongst others, leads, some rotor-arms and caps are highly resistive. Modern cars have one coil per pot and the coil sits over the plug to eliminate all that. This means a classic will never compete with lighting-off a given mixture like modern set-ups. It's possible to offset this with an understanding of all you can do to get things to optimum. 123 with a proper coil; decent HT leads and the correct curve, helps lots.
If you were running high rpm or 8+ cylinders - or both - you've less dwell time. This just when you need more. One more reason the world left points and a dizzy behind.
This explains why the Yanks are all over coil-power. Running 8 pots anything like well with a stock dizzy you have to be. Hence their their obsession with MSD / Pertronix Digital HP etc. They're running something like a 0.4Ω coil and 40 thou gaps with those things. A rolling-road session is unbeatable. If you can't stretch to that Roland at ACR (https://www.automotivecomp.com/prices/) sells 123 with a curve done via his RR. That'd be your better option over guessing.
And of course a wideband.
https://www.youtube.com/results?search_query=ac+dodd
OK, along with that link to AC Dodd again, that's me done.
Be minded as the energy from each spark leaves the coil its hobbled via two lengths of HT lead and the jump across the gap twixt rotor-arm and cap.
For radio suppression reasons amongst others, leads, some rotor-arms and caps are highly resistive. Modern cars have one coil per pot and the coil sits over the plug to eliminate all that. This means a classic will never compete with lighting-off a given mixture like modern set-ups. It's possible to offset this with an understanding of all you can do to get things to optimum. 123 with a proper coil; decent HT leads and the correct curve, helps lots.
If you were running high rpm or 8+ cylinders - or both - you've less dwell time. This just when you need more. One more reason the world left points and a dizzy behind.
This explains why the Yanks are all over coil-power. Running 8 pots anything like well with a stock dizzy you have to be. Hence their their obsession with MSD / Pertronix Digital HP etc. They're running something like a 0.4Ω coil and 40 thou gaps with those things. A rolling-road session is unbeatable. If you can't stretch to that Roland at ACR (https://www.automotivecomp.com/prices/) sells 123 with a curve done via his RR. That'd be your better option over guessing.
And of course a wideband.
https://www.youtube.com/results?search_query=ac+dodd
OK, along with that link to AC Dodd again, that's me done.
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