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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Electronic Ignition

I want to install an electronic ignition into my late '50 TD. The distributor is original, but has been refurbished by Advanced Distributors. How do I know if I have a symmetrical or asymmetrical cam? Moss lists both for the TD. Thanks......
Bill Reid TD4618

This might help.

Tim
TD12524

Tim Burchfield

Better way to tell, measure across the
flats. The symmetric and asymmetric cams are .661". The high lift cam is.640".

Tim
TD12524
Tim Burchfield

Better idea - forget about the cam and buy a pertronix LU-146LS. The LS stands for Lobe Sensing. It does not use the ring of magnets that encircles the cam. I've been using one, flawlessly, for over two years now.

The work done by Jeff will not be wasted. I would suggest that you install it on a new distributor plate. Just get the model that's appropriate for your ground, positive or negative, and install it following their instructions. Don't green-thumb it. Bud
Bud Krueger

Well Tim, not getting your numbers. I'm closer to .680 - .690. However, there is a distinct possibility that I don't know what I'm doing. I think it is symmetrical, if I understand the subtle differences in the diagrams. Found the relevant section in the manual where it refers to specific numbers. I am going to look and see if I have a pic when it was out of the car.
Bill Reid TD4618

Bud, I have a LU-146LSP12. This whole adventure started when I went to change it out and found that the points are bradded onto the plate. Didn't want to jury rig it. I went to moss to order an Ignitor with a plate. Then got into the "what kind of cam do you have" thing which led me to ask the question. Is it possible to buy a new plate and use the ignitor I have? It is positive ground.
Bill Reid TD4618

Yes. I opted to do the same thing. I took out the plate containing my LU-146 and built up the new plate with the LU-146LS. If I want to I can readily reinstall my original points plate, of my LU-146 with the magnet collar, or the LU-146LS without the collar.

My experience with the Moss folks is that they don't seem to understand what the Pertronix LS series is about.

The LU-146LS is 'cam-neutral'. Install the LS on the new plate and install the plate into the distributor. Just be sure to wire it up according to the Pertronix instructions. See http://www.ttalk.info/Tech/pertronix_igniters.htm and look at the positive ground installation instructions. Bud
Bud Krueger

Thanks...
Bill Reid TD4618

Bill - "Well Tim, not getting your numbers. I'm closer to .680 - .690."

The way I found which cam I had was to look, not only the cam profiles, but also the key way on the cam. The symmetrical and the high lift are hard to look at and determine which you have until you also look at the key way on the bottom of the cam. Cheers - Dave
DW DuBois

I am not familiar with the kits mentioned but it is worth checking how easy it is to set the timing with them. Generally electronic ignition set ups need to spin at a fair speed before they will spark. With some cheaper versions the only way to set the initial timing is to remove the plugs, crank the engine with the starter and use a strobe. The more expensive ones have a LED which flashes as you twist the distributor.

Jan T
J Targosz

The Pertronix Igniter emulates a set of points for timing. You can readily do it with a 12v test lamp. Just remember to disconnect the test lamp before you try to fire up the engine. Bud
Bud Krueger

Ive got to ask,,,, why do you want to install an electronic ignition ??? Is there a problem with your point type ??

Steve
SPW Wincze

Steve, from the first time the ignition is turned on the points start to lose performance and durability. The contacts begin to corrode and the cam follower starts to wear away. Sure the points may last a very long time but they will lose accuracy during that time. Adjusting the gap will restore some of that accuracy but that is a job not required of a electronic system. An electronic ignition system eliminates point bounce, arcing and diminishes the effects of cam wobble and wear. And there is no condenser to fail. The Pertronix Ignitor II for the Lucas distributor even changes the dwell to match rpm and adjusts spark timing at higher rpms. Here's the reason that's important, "...the HEI system developed by General Motors in 1974 is able to generate 35,000 volts at engine speeds above 3,000 rpm. A typical breaker point system, on the other hand, developed a maximum of 20,000 volts at 1,000 rpm. Above this speed, the voltage dropped off." Asking why change points for an electronic ignition system is like asking why change a mechanical watch for a digital.

Regards

Tim
TD12524
Tim Burchfield

Hi Tim

I prefer all my mechanical watches. I had a pertronix ignition module in my MGA and it is the only time I have broken down far from home. I did not carry a spare distributor, it cost me for a tow. I have switched back to points in all my cars at least if anything goes wrong you can limp home, not so with electronic. If you do want the extra volts for high speed work carry a spare distributor with points in the boot.

Barry
B Bridgens

Barry, I would imagine you would have to admit, however, that the digital watch is more accurate than the mechanical. If I was that worried about an EI failing I'd carry a spare plate with the points and condenser attached. With the Pertronix system you don't nee a new or different distributor. I see far more complaints about coil and condenser failures than I do about EI. If people stopped using innovative automotive products because of one failure we'd still be driving model Ts. :-)

Tim
TD12524
Tim Burchfield

There are lots of electronic distributor people that carry a spare points plate with them as a spare. How many times do you see a points person carry a Pertronix as a spare?

I think that says something.
Lew Palmer

Lew, not exactly a logical example. Why would someone committed to a points system use an EI system as a backup? If they trusted the EI as a backup why have points in the first place? And really, it isn't how many people carry spare plates in case their EI fails. It's how many people with EIs ever need to install the spare plate. Unfortunately this discussion will devolve into what people prefer rather than the merits of their preference. I'm sure there were heated discussions back in the day about the merits of an electric starter over a hand crank. I can imagine someone saying "I had a electric starter fail once. I've gone back to my hand crank, no more electric starters for me." Some things never change.

Regards

Tim
TD12524
Tim Burchfield

Sorry Lew, I missed your point about electronic ignition distributors. The reason those people carry points as a backup is that a spare EI system is expensive. But I still haven't heard of a massive failure rate for EI systems. There are millions of EI systems on the road but no one is coming out with a car equipped with a points distributor anymore. Must be a reason for that.

Tim
Tim Burchfield

Over the years I have installed Pertronix units at customers' requests, perhaps a dozen all told. Of these, four have failed, all after a year in service. Two required expensive tows of many hundreds of miles; the other two owners carried points plates and knew how to install them (one with my coaching over the phone at 11pm...).

There are certainly advantages to an EI system, when it works. When it doesn't, there is nothing to be done for it. Points can almost always be made to work, even when burned. People carry points plates exactly BECAUSE the EI units are not 100% reliable.

I am sure there are many Pertronix units that are functioning as expected, and I have heard of fewer failures in recent years. I just don't install them any more.

Tom Lange
MGT Repair
t lange

Hi

When are we all going to install electric motors in our cars and get rid of the unreliable XPAG after all that is the way forward. Not for me I'm afraid, still old school that's why I drive old Mgs and old Porsches. Cancun son gout.

Barry
B Bridgens

Barry, hyperbole much? :-) There is a difference between making improvements to a vehicle and abandoning the vehicle and its drive train entirely. Do you have a problem with gear box upgrades, rear differential replacement, LED lighting, improved cams, larger valves and radial tires? Do you seriously consider going from points to an EI system akin to throwing out the XPAG for an all electric motor?

Tim
TD12524
Tim Burchfield

Just a joke, folks. But seriously, ask Jeff Schlemmer's (Advanced Distributors) opinion on electronic ignition.
Lew Palmer

It's truly a shame that this thread has become a source of ugly attacks. I'd be happy to share my Pertronix experience through my email address shown above. Bud
Bud Krueger

Bud, what are you referring to as ugly attacks? I seriously don't see any personal attacks in the thread above. If anything I've said is being interpreted as an attack on someone I certainly didn't mean it that way. But then again, my sense of humor is not everyone's cup of tea. If anyone was offended I apologize.

Tim
TD12524
Tim Burchfield

Understood Lew. I'd like to know why Jeff has a negative opinion of the EI system. Anyone have a source for his comments on the subject.

Tim
TD12524
Tim Burchfield

http://mgaguru.com/mgtech/ignition/ig203.htm
Lew Palmer

I generally enjoy reading these threads-but I have not enjoyed this one.

Lionel.
L.F. Thorne

Thanks Lew. Although the article was written in 2004 and the author (not Jeff) never once mentions the condenser. It seems there is a lively discussion from time to time about the poor quality and failure of today's condensers. But the choice of what ignition system is entirely up to each person. I do find that dismissing a system because of one failure and the idea that a 100 year old method of producing spark is superior to modern electronic system rather odd. If anyone is offended by my thoughts I apologize profusely. I may even go out and reinstall the points and condenser just to punish myself.

Tim
TD12524
Tim Burchfield

To each his own. Nothing wrong with electronic ignitions, per se. But there have been some quality issues with some Pertronix units over time. Most people I know that have had them and subsequently removed them have told me Pertronix's tech support is virtually non-existent.

I have a Jeff Schlemmer rebuilt distributor in my TD (and PA and PB) and I have never had an ignition problem with any of them in over 35 years. (With 15 of those years on the rebuilt distributors.)
Lew Palmer

Atually,my question was to the originator of this thread,,,, Bill Reid,, it was just a simple curiousity question that I guess never had a chance to get answered...
Wow,,,


Steve
SPW Wincze

I bought a pertronix system 10 years ago. It is still in the box. The car does not stand still long enough to change out the points system. Someday I will sell the pertronix on eBay. Personal preference to experience these cars as designed and built. I have a Ford Fusion to enjoy all the modern technology.
Regards, tom
tm peterson

I think that like engine oils, silicone brake fluid and various other subjects, EI and particularly Perttronix ignition systems remain one of the arguments that will continue to rage.

Both sides have valid points - when Pertronix works, it is astonishingly good, with precise timing and reliability. When Pertronix stops working, it is by definition inopportune, and the car is dead in the water. Unfortunately, one cannot predict when it might stop working, so having a back-up points plate is a worthwhile thing.

As in life, all the good experiences are usually diminished by a few bad experiences; outrage speaks louder than calm approval. So I think we need to all agree that when Pertronix works it is great, but there is no predictability when or if it might stop working.

Tom Lange
MGT Repair

t lange

I second Tom. My Pertronix is about 10 years old and has been perfect. So was my Crane electronic with separate box before that. One of the three times the car was towed home was when the points rubbing block broke years ago. I do carry spare points plate, phone and AAA card on any road trip so I'm ready for whatever! George
George Butz

Tom, good post. I agree that there is no predictability when an EI system will stop working but that applies to every electrical component on a car and especially the ignition system. I'd wager those using points in they distributors are also carrying a spare set of points and condenser. The complaints about EI systems in general and Pertronix specifically are usually based on older products. If you search the archives for "condenser" and "points" you will find a great deal of conversation about problems and failures. The bottom line is that an EI system is superior to a points system in every respect other than cost. If someone disagrees please tell me how a points system is better. Now I'll just sit back and wait for that free system from Petronix (that's a joke folks).

Tim
TD12524
Tim Burchfield

Most of the debate on electronic ignition so far is amongst our US colleagues who, I understand, do not have to use petrol doped with ethanol (bio-fuel). In Europe we have to use bio fuel doped to at least 5% and often 10% or more. This can have a significant impact on the tickover and road performance of XPAG/XPEG engines because the advance curve needed is not obtainable from a standard weights adjusted advance distributor. Those with the addition of a vacuum advance (like a B series MGB engine) are much more likely to obtain a satisfactory advance curve.

If you subscribe to the UK on-line publication "Totally T Type 2" there is a much more detailed explanation in a series of articles written by Paul Ireland of Manchester University, which should help explain why in Europe there are distinct benefits to using a fully electronic and programmable ignition system. The next edition of Totally T Type 2 will have an article by me describing the problems I found on my XPEG engine, the partial solution of installing a CSI electronic distributor, and backed up with 3 rolling road sessions including printouts of the torque and brake horsepower curves obtained.

Hopefully our American colleagues will understand why some of us in Europe have gone down the electronic route.
N D Wallace

ND actually we do have to use ethanol doped gasoline here in the US. We do have options for non ethanol petrol but they are not available everywhere.

Tim
TD12524
Tim Burchfield

Back in the 70s we built our own Capacitive Discharge Ignition System. It was triggered by the points but there was no current flow so no burning/arcing of points, only wear on the rubbing block.

This meant we could use a plug which when used returned the system to original. We did have a few teething issues, most bothersome was during cranking the battery voltage could drop below what we needed to make it work. We changed a few parameters and it was better.

We used to open the plug gap up an additional 10thou as well.

Could not afford a dyno so no idea if it worked, but points life definitely improved.

Too many years and too many beers later I can't remember how it worked, I do remember one big power transistor mounted to the case as a heatsink.

Peter
P G Gilvarry

I was first introduced to Pertronix through the late Skip Kelsey in December 1999. At that time I was doing some research regarding Hall Effect Transistors. When I saw that the Pertronix Igniter was based upon such a device and that Skip was using one, I had to try it. I installed one into Lazarus in early 2000. I installed it on a separate plate, removed my points plate and put it into my 'just to be safe' box in Lazarus' toolbox. The only time that it has been out of the box has been to demonstrate how quickly I could reinstall it.

I regularly gave tech sessions on the Igniter at Club events, wrote it up in The British Marque and helped a number of folks through the BBS. The only failure that I had related to Igniter was in August, 2010, due to the effect of the magnet collar on the carbon brush in the distributor cap, see http://www.ttalk.info/Failure.htm .
During that time I never experienced the failure of any negative ground Pertronix Igniter from anyone that I dealt with. All of the positive ground failures could be traced to their having been wired incorrectly.

In September, 2014, a posting in the thread "Pertronix Ring Too Tall" was made by Jan Kristoffersen of Norway in which he introduced the existence of a Pertronix Igniter that didn't use the magnetic collar. We then discovered that this was their LS (lobe sensing) series. We also learned that the LS series is a much more complex circuit than the basic Igniter and is sensitive to EMF as allowed by hard ignition wires.

I spent a good bit of 2014 learning how to create hybrid non-EMF ignition wires that would allow themselves to be screwed into our Lucas distributor caps and installed an LU146LS. The first one that I received had a bit of a glitch while accelerating through 2800 to 3200 rpm. I discovered that the rivets holding the module onto its mount were slightly loose. I reported this to a Pertronix engineer with whom I'd been corresponding since 2001. He swapped it for a new one and the problem disappeared. I've been running that LU-146LS since the Fall of 2014 with no glitches whatsoever.

FYI, my original LU146, with its magnet ring, has joined my old points plate in the box for show-and-tell. Have I just been lucky? I think I've just followed basic engineering practices. If someone were to ask me about installing any sort of non-points ignition the first thing that I would tell them to do is to switch to a negative ground system.
Bud
Bud Krueger

Fuel with 5% ethanol isn't biofuel. There are plenty of us in Europe still using points ignition. However electronic points replacement are popular here because they are so inexpensive compared to
Pertronix. Accuspark, Powerspark, Lucas and others offer electronic points replacement at around 35 a go ($50 or so), which is no more than a set of points and capacitor and much less than Pertronix.
Dave H
Dave Hill

Dave are there any of the manufactures you mentioned (other than Pertronix) that offer an EI for the TD series cars? I like the prices you mentioned. Are you saying that people are switching to EI in the UK because it is cheap? Are you in disagreement with N D Wallace's post above?

Tim
TD12524
Tim Burchfield

Bud, thanks, you just explained why the top of my rotor had a black ring on it. I installed an old Pertronix Ignitor while I rebuilt an old distributor. I guess the rotor piece was too high. How was that rectified? I don't want to start grinding without knowing what I'm doing.

Tim
TD12524
Tim Burchfield

I obtained an EI kit from one of them for my TF, but never fitted it because the original distributor was found to be too worn and instead I bought a 45D points distributor set up for my engine by J Schlemmer. I think it was Powerspark I got it from. All I am suggesting is that at the low price these are obtainable for over here, many think its worth a try and little lost if it doesn't work. It also makes carrying a spare affordable. As far as I know there is nothing to choose between brands.
Dave H
Dave Hill

Tim, to the best of my knowledge there has been no effort to work around the issue. It's a total non-issue with the LS versions.

Dave H -- Are you saying that the 45D distributor will fit into a TD/TF? Bud
Bud Krueger

I purchased a Pertronix from Skip Kelsey back in the early 1990's. Still in my TD and running fine (I do have a set up points plate in the tool box). Saying that, I also have put two in my MGB. Both failed. I have Jeff's plate, points, condenser, rotor and cap in the B now.

As long as the one in the TD keeps running, I will keep it. If it fails, probably will put points back in.

The Pertronix is the only modern part I have put on the TD.

Bruce Cunha

Yes the 45D distributor will fit in an xpag with a little modification - mainly swopping the drive gear from the original distributor. If you buy a new distributor from Advanced for your xpag, it will be a 45D.
Dave H
Dave Hill

The EI 123 hasn't been mentioned thus far. I purchased one of these a couple of years ago & have installed same but am yet to fire up the old girl. I expect great things from this item based on the recommendations of others here who have installed it. As Bill (the originator of this post) wants to install an EI perhaps he may want to look into the EI 123. I seem to recall they come from Holland. Cheers
Peter TD 5801
P Hehir

I also have a 45D fitted to my TF, I have also fitted a Boyer-Bransden electronic ignition. This retains the points and gives much better starting and tickover.
I cut a square hole in the passenger foot ramp with a hinged lid and it cant be seen unless you know where to look.In there is the original dizzy plus points,plugs,rad cap,stat and various other bits.
Ray TF 2884
Ray Lee

The Hall effect electronic systems all still rely on the auto advance mechanism of the distributors, namely 2 weights with spring control. My original dizzy was very worn, which started my thinking about a fully electronic replacement for the existing Pertronix, and the more recent research about advance curves, ethanol fuel, combustion chamber design, etc., finally tipped me over into buying a fully electronic system. My decision had nothing whatever to do with Pertronix or points reliability questions.
N D Wallace

For those of you running older EI systems you may want to look at the latest iterations like adaptive dwell, timing changes at higher RPMs and much higher voltages than points or earlier systems. These things just aren't available with the traditional points systems found in our cars. The EI technology is rapidly changing.

Tim
TD12524
Tim Burchfield

This thread was discussed between 19/08/2017 and 23/08/2017

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.