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MG MGB Technical - Lumenition Magnetronic Ignition

Does anyone have recent experience with this electronic ignition that Moss offers? I like the simple concept of putting everything inside the distributor, but does it work properly?

Tore
Tore

Tore. My daughter's 77B had the Lumenition system in it for many years. It fit into the original 45DE4 distributor and has a heatshield and electronic circuit that is remotely mounted. Recently, however, the car would quite for a second (jerk and the tack dropping to zero, the picking up again). Since the electronic points replacement systems are difficult to troubleshoot, I replaced the distributor with a 45D4 "Euro Spec" dizzy. No problems so far and much easier to troubleshoot the system when there is a problem. Les
Les Bengtson

I have the Magnetronic system in my '72 B. It seems to work fine (usually) and is a lot simpler than constantly fiddling with the points. However, keep the old points/condenser AND fixing screws in the glove box. It dumped me once and I stupidly had everything with me but the retaining screw for the condensor. A very helpful RAC patrol eventually helped get me home by connecting the condensor directly to the coil and I limped home.
steve
Steve Coulson

Tore,
I've have the pertronix (which is a US product that works the same as the Magnetronic)in both my B & TD. I couldn't be happier with the product. In the case of the TD, I have a slight wobble in the dizzy, the Pertronix helps compensate for this. Of course I will fix that this year!
I agree that you need to carry a back-up as there is no way of telling when it will go, and when it does, it can't be adjusted etc, it just dies. I carry a spare Pertronix rather than a spare set of points, more expensive but it works for me. Either way, carry a back-up!
Robert Dougherty

Tore,
I might add that I have had the Pertronix in my B for 5 years now with no problems. Well over 45,000 miles traveled.
Robert Dougherty

My experience much the same, have had it fitted to my '66 BGT for a couple of years now. Beats the hell out of adjusting the points every few thousand miles! The only time it's let me down the spade connector crimps had become intermittent. Recrimp, no problem. If you have an early distributor you have to cut down the mounting pin for the points so that the Magnetronic hall-effect detector will sit flush on the base plate - no problem, but bear in mind that if you need to convert back to points in an emergency you may find them moving about too much on the pivot post. Also watch the orientation of the magnetic trigger disc - it should only fit one way, but there was a batch which fitted wrongly and threw the phasing of the spark out. I still haven't got to the bottom of mine - I had a new disc from Luminition because my disc fits differently to photos I have seen in magazines but the new disc is the same! Works OK, I just have my suspicions about how accurate the phasing is.

Tim.
Tim Jenner

I found the timing after fitting Magnetronic was very different from that with points - so much so the car hardly ran. So if you carry points as a backup, you will need a timing gun as well. I don't use it now

Tony
Tony Bridgewater

Thanks for your information everybody. What a magnificent way this is to benefit from other people's experience!

A conversion to this system is very tempting, but as my MGB is from 64, I probably have the little problem with the mounting pin, Tim. Have to think about it.

Tore
Tore

Tore. A couple of thoughts. First, several people have mentioned the need to constantly reset the points. Funny. My 25D4 has the points set at emissions testing time and then runs fine for the rest of the year. This is in a 68GT used as a daily driver (primary). My 79 LE is the back up daily driver and fun car. I had it emissions tested recently, but did not have time to give it a tune up before testing. I was running out of time and had a lot of other things going on. I thought to take it in for initial testing which, I thought, it would fail, but it would also give me an additional 30 days in which to tune it up. Imagine my surprise when not only did it pass the test, but with readings that were exceptionally low. Thus, not all of us are having significant problems with points wear in properly maintained distributors. And, since the distributors should be cleaned, inspected and lubricated on an annual basis, points are not really the problem that some seem to think they are.

If, however, someone should want to change out to a pointless ignition system, and there is a problem with the base plate requiring modification, there is a very simple solution. All of the base plates for the 25D distributor that I have examined, something over a dozen, seem to be exactly the same. Thus, it would be relatively simple to simply pick up a spare base plate to be used with the conversion to the pointless ignition system. Carry the orignal baseplate, with points and condensor already installed, as a back up. Les
Les Bengtson

The Pertronix is an excellent unit. I have it installed in the 25D4 distributors in my MGs and the single Sunbeam Alpine that shares space with them these days.
Charles Edwards

I have the Magnetronic system on my car, and it's worked flawlessly since I put it on. Admittidly I did crimp new lucars onto the leads beforehand, as the ones on it were somewhat worn (I got the unit second hand, as a swap for shift light) and looked loose.

I have to say though that it affected my timing curve, as you don't get the resistance of the points to stop the advance weights springing out. YMMV.

With earlier disis, it is possible to cut the pin down to exactly the same size as the later 25D models, without even removing the plate from the disi. The later 25Ds ran normal points with this short pin, so I see no reason to think that you would have any trouble with a shortened pin.

Anyway, my verdict is that it's a lot more reliable than points and (usually bad when new) condensers.

Cheers,
--
Olly
Oliver Stephenson

Les - You're quite right about the baseplates being interchangeable, but changing them with the dizzy on the car would be seriously hard work!

Tim.
Tim Jenner

Like Les I never have any problem with the points, set them up when changing them then just check the dwell (meter on the coil terminal) at each service. On the V8 I must have run a set for 40 or 50k before I thought I had better change them, I was doing 150 miles per day at the time. Many people who convert to an electronic replacement find the hard way that they should carry a set of points and a condenser as a spare - if they can be retrofitted, some systems seem to need the points plate to be butchered before they will fit. In a recent mag article someone writing about their long0-term ownership said the only time the car let them down was when the after-market electronic ignition failed.
Paul Hunt

My magnetronic failed after 18 months. I've since fitted a brand new ditributor with points.
I have to say that the car ran better with the electronic ignition, but mine just simply switched off. Yes, you can carry a spare base-plate etc., but it would be no fun changing on a hard shoulder. Or at night. Or in the rain.
Consider a different type of electronic ignition.

Mike
Michael Watkins

About 2 years ago I fitted an Ignitor, which I believe is the UK version of the Pertronix. It lasted about 12 miles and went completely dead. I gave them the benefit of the doubt and fitted a second, which was supplied free of charge. It did better this time and we clocked up 360 miles before failure. Fortunately on each occasion I carried a built up base plate and only needed to do a 10 minute swap, fine if you're not on the Motorway.
Have since tried the Newtronic (supplied by Moss)this is a full optronic type similar to Luminition but much cheaper. So far it has worked well and I have no complaints, the module has long enough wires to fit under the dash and so cannot be seen under the bonnet (for the originality boys). However, after two failures I'm still nervous and when we rally the car on the continent I always refit the good old points for peace of mind.
If you have to do it go for a full Optronic !

Graham
GRAHAM CHERRY

I installed a Lumenition Magnetronic Ignition last January when I rebuilt my distributor. What a difference. My car (68B) idles at 600-700 rpm so smoothly I’m still getting used to it - when I come to a stop at intersections I have to look at the tach to verify that I haven’t stalled and that the engine is still running. Generally the car starts easier and runs much better. Of course, the improvement may not all be due to the Magnetronic and I may have just had a bad ignition set up previously. During the rebuild of the distributor I replaced the plates where the points sat (had groves worn into them that seem like they would have interfered with smooth advance movement) and the vacuum advance which was shot. But still, even before when I put in new points/condensers I don’t recall it running this well. I’m a little concerned however about the experiences reported on the Board with failures of various electronic points replacement systems (of which the Magnetronic is one). Seems like this has happened to a number of people – odd for solid state devices. I plan to build up a spare points based distributor from the leftover parts just in case. Hope I never need it.
Boris

I wonder how many of the failures of the units are like the one that I had with my Ignitor. The unit itself didn't fail -- I discovered when I did a post-mortem on it that the ground wire had fatigued and broken where it entered the unit. If I could have mended the wire I'm sure the unit would have functioned perfectly. The moral I believe is to be very careful about how you route the wires...
Rob Edwards

Boris. When I rebuilt my distributor I was also amazed at how well the car idled and the performance increase. Funny how cleaning the dizzy internals, replacing the bushing, lubing everything and installing a new vacuum advance makes for a better running car. If one performs periodic preventive maintenance, on an annual basis, this quality of performance will be maintained for an extended period of time. And that is the bottom line. The coil triggering mechanism, as long as it is working correctly, is relatively unimportant. Ensuring the distributor, as a system, is working correctly and in good repair should be the focus of discussions. Les
Les Bengtson



I have just recived a set of Crane XR700 ign kit to replace a bad electronic ign set on my 78B.
After reading about the pros and cons on the latter I am a bit concern and debating weather to install a crane ign kit or just convert to a more reliable point system.

On a related issue, I would appriciate some help
on how to remove the shutter disk from the dazzy stem.
Nate

Just installed an MSD 6L (rev limiter and cd unit) to my pertronix II ignition....smoother running and a very easy install.


rn
RN Lipow

This thread was discussed between 08/03/2003 and 16/03/2003

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