Morris Minor Owners Club

Hi,
I have a 1968 1098cc and I plan to upgrade to an electronic ignition but don’t know if I need a 25D or 45D, can anyone help.

Thanks

Craig

If standard, probably a 25D. Try posting this in the electrical section - there are some very knowledgeable people there.

Craiggubrath wrote: ↑Tue Sep 23, 2025 9:19 pm Hi,
I have a 1968 1098cc and I plan to upgrade to an electronic ignition but don’t know if I need a 25D or 45D, can anyone help.

Thanks

Craig

I've reported this as needing moving to 'Electrical', so don't go posting it again.

Are you thinking of replacing the Distributor because it is worn out mechanically, or have you not considered just getting as kit that fits what you have.
But I don't understand why you're asking; even if replacing what you have, you surely just get a direct replacement?

I thought the 45D was only introduced in the mid 70s, so it wasn't original for you car, but may have been fitted by a PO.

What's fitted now?

I assume you are wanting to fit one of the electronic ignition kits that uses the Hall Effect and is fitted within the distributor? Or are you considering replacing the entire distributor with one of the Lucas copies with the electronic internals already fitted?

Your 1968 car with a 1098cc would originally have had a Lucas 25D4. Whether it still has a 25D4 you would have to determine.

The distributor is marked with the model as arrowed in the photo. The exact model variant (which is related to the advance curve) is stamped on the side of distributor.

If your distributor is badly worn then fitting an electronic ignition kit is unlikely to help much. The Far East Lucas copies are probably better than a very worn out original but they are not very well made. Though expensive, a professional rebuild of the original distributor is the best option.

Stephen

geoberni wrote: ↑Wed Sep 24, 2025 9:55 am

Craiggubrath wrote: ↑Tue Sep 23, 2025 9:19 pm Hi,
I have a 1968 1098cc and I plan to upgrade to an electronic ignition but don’t know if I need a 25D or 45D, can anyone help.

Thanks

Craig

I've reported this as needing moving to 'Electrical', so don't go posting it again.

Are you thinking of replacing the Distributor because it is worn out mechanically, or have you not considered just getting as kit that fits what you have.
But I don't understand why you're asking; even if replacing what you have, you surely just get a direct replacement?

I thought the 45D was only introduced in the mid 70s, so it wasn't original for you car, but may have been fitted by a PO.

What's fitted now?

Apologies, I’m new to the site and didn’t realise there were different section to ask questions on, will keep this in mind for the future.

Craiggubrath wrote: ↑Wed Sep 24, 2025 5:26 pm

geoberni wrote: ↑Wed Sep 24, 2025 9:55 am

Craiggubrath wrote: ↑Tue Sep 23, 2025 9:19 pm Hi,
I have a 1968 1098cc and I plan to upgrade to an electronic ignition but don’t know if I need a 25D or 45D, can anyone help.

Thanks

Craig

I've reported this as needing moving to 'Electrical', so don't go posting it again.

Are you thinking of replacing the Distributor because it is worn out mechanically, or have you not considered just getting as kit that fits what you have.
But I don't understand why you're asking; even if replacing what you have, you surely just get a direct replacement?

I thought the 45D was only introduced in the mid 70s, so it wasn't original for you car, but may have been fitted by a PO.

What's fitted now?

Apologies, I’m new to the site and didn’t realise there were different section to ask questions on, will keep this in mind for the future.

Don't worry about it. Did you get the answer to your question?

Stephen

Craiggubrath wrote: ↑Wed Sep 24, 2025 5:26 pm
Apologies, I’m new to the site and didn’t realise there were different section to ask questions on, will keep this in mind for the future.

Don't worry about it, I just mentioned it because Mr Spigot has suggested posting it in 'Electrical', but Admin can move it if they wish.

But Stephen and I have both asked for further information from you to let us give you some appropriate responses....

Now moved to Electrical

Hi,
Thanks for your help, I bought my moggie in June, my first vintage car, she’s a great runner & in good condition but at 57yrs old needs a few things done, I’ve been working on the interior and now moved to the mechanical side, not much need (new exhaust, fuse box, small oil leak etc) going to give her full service so planned to upgrade to an electronic ignition at the same time, mostly just for reliability, turns out I need a 25D, managed to find the stamp on the original.

Thanks again

Craiggubrath wrote: ↑Fri Sep 26, 2025 9:50 am Hi,
Thanks for your help, I bought my moggie in June, my first vintage car, she’s a great runner & in good condition but at 57yrs old needs a few things done, I’ve been working on the interior and now moved to the mechanical side, not much need (new exhaust, fuse box, small oil leak etc) going to give her full service so planned to upgrade to an electronic ignition at the same time, mostly just for reliability, turns out I need a 25D, managed to find the stamp on the original.

Thanks again

So you have a choice, replace the entire Distributor, or just fit the correct module to the existing Distributor.
There's a lot of choice out there, my car came with an electronic conversion when I brought him, and I've had no problems with it.
It was blamed, by two different RAC techs, for a couple of breakdowns I experience in the first few months of ownership, but I eventually traced the issue to the Coil, not the Electronic 'points' system.
If they'd been capable of using a multimeter, they should have been able to locate the intermittent open circuit in the Coil while it was at the side of the road.
There's a tip for you there, carry a spare Coil because some modern ones are terrible quality.
viewtopic.php?p=636467#p636467

Another thing to check with a new purchase is that if the car has been converted to Negative Earth, ensure the connection at the Coil are the opposite to what the wiring diagram shows. If it's wrong, it overheats the plugs, shortening their life.
viewtopic.php?t=70183

At the risk of opening a terrible can of worms, you don't need to fit electronic ignition to ensure "reliability".

There have been poor quality condensers around for years but providing you fit a good quality condenser and check the points gap as part of routine servicing, the standard points system is very reliable.

As I mentioned before, if your existing distributor is worn with barely functioning or non-functioning centrifugal and vacuum advance, then electronic ignition is not going to improve matters.

Stephen

svenedin wrote: ↑Fri Sep 26, 2025 11:03 am At the risk of opening a terrible can of worms, you don't need to fit electronic ignition to ensure "reliability".

There have been poor quality condensers around for years but providing you fit a good quality condenser and check the points gap as part of routine servicing, the standard points system is very reliable.

As I mentioned before, if your existing distributor is worn with barely functioning or non-functioning centrifugal and vacuum advance, then electronic ignition is not going to improve matters.

Stephen

Very true. Had Basil not already had the electronic system when I brought him, I might not have bothered to change from Points.
However, it is nice not to be fiddling around adjusting points.
I did find that Basil's Dissy had a non functioning vacuum unit back in 2018, I just looked up the post I wrote about it. I'd had him about a year and was still on a steep learning curve. viewtopic.php?t=69145

Yes it's very common for the vacuum unit to fail due to a perished diaphragm. They can be tested with a hand held vacuum pump (such as is used for bleeding brakes). The vacuum is applied and then you just watch for the points platform to rotate inside the distributor. I forget the exact readings that the advance is supposed to operate at. Likewise, the centrifugal advance can seize or the springs become weak and it operates too soon. Also the spindle bearing can wear which causes the cam to wobble and the timing to drift. It can all be sorted out with a professional overhaul. You can't expect an engine to perform well if the ignition timing is unreliable. We don't have many horses to spare with these cars so it really makes a difference!

Stephen

svenedin wrote: ↑Fri Sep 26, 2025 11:03 am At the risk of opening a terrible can of worms, you don't need to fit electronic ignition to ensure "reliability".

There have been poor quality condensers around for years but providing you fit a good quality condenser and check the points gap as part of routine servicing, the standard points system is very reliable.

As I mentioned before, if your existing distributor is worn with barely functioning or non-functioning centrifugal and vacuum advance, then electronic ignition is not going to improve matters.

Stephen

If the electronic ignition system fails on the road, then you are pretty much stranded. With the points system, there is a much greater chance of a roadside fix, especially if you carry the relevant spares. With good quality points, condensor, rotor arm etc. the points system is reliable!

Agreed. I did fit one of those Lucas copies with electronic ignition. The vacuum advance unit will be the same on all of them and not set up for a Minor's 25D4 either. It didn't cause any issues but that was my train of thought. Other than carry a spare distributor and have to change the wiring (it's different for +ve earth), or a spare electronic kit (not cheap), I had my old distributor refurbished by Distributor Doctor and refitted that.

"If the electronic ignition system fails on the road…."

No system is foolproof but I have had a Lumenition Magnetronic electronic system for 25 years and never had a problem. Yes, condenser and points are easy to fix by the roadside and can be very reliable, but the number of problems reported here and on other forums suggest condenser/points problems are significantly more common than electronic ignition problems. I’d rather reduce the risk of breaking down as much as possible. Good quality components always reduce the risk of breakdowns and an electronic system is about 5 times the price of a good set of points and condenser. I picked up a NOS Lumenition set off EBay for a fraction of the new price and keep this as a spare, but doubt I’ll need it.
The main thing for novices is to understand what these components do, the risks of cheap copies, and how to keep the ignition working reliably. Your car, your money, your choice.

"the number of problems reported here and on other forums suggest condenser/points problems are significantly more common than electronic ignition problems"
Possibly, although there may be a greater proportion of Minor owners still using the points system which would skew the numbers. I don't know.
We all would rather reduce the risk of breaking down and, if using points, maintaining/servicing properly and using quality components will address this.
Your 25 trouble-free years with Magnetronic is a good recommendation though.
What was that Stephen said about a can of worms?

Mine came fitted with Pertronix and so far 3 years trouble free and starts instantly.
Although I carry a spare complete distributor,with cap and leads, coil, points, condenser and plugs. All of which I hope never to need but its a bit like insurance.

I made my own capacitive discharge electronic conversion from a kit. back in the ‘70s. Worked perfectly well for a ‘cooking engine’ but had limitations once the rpms were upped seriously for hotted specials.

The kit was, I think, supplied by the magazine suggested supplier.

It was from ETI (Electronics Today International. I’ve found a project build in the September ‘73 issue but it may have been simplified in a later issue as mine was definitely a ‘negative earth only’ example. I’ve not searched later issues.

It still used the points as the ignition activation via an SCR, so a couple of toggle switches were included to make the change back to the Kettering system as simple, quick and easy as it could possibly be. It never failed on me but started to run out of steam above 6000rpm as I recall.

For a simple no frills conversion it served me well. I had previously suffered a night out in my car, with a failed condenser, and didn’t want another.