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MG MGB Technical - Ignitor II

There's a lot of info on the site (good and bad) about pertronix Ignitor system. Has anybody tried the Ignitor II or is it just a sales gimmick with little benefits to an MGB setup?

cheers
philip
Philip

Haven't taken the time to order, but plan to do so in the future. I will post any plus or minus data when it is installed. FWIW, I have a 77 B with a 45D4 distributor.
R Hill

I've used them in many different cars to include my B and my C I have never had a problem, but I've "heard" that they fail. But hey what item made by man is perfect?
That said I like the set up and if you are handy and you get stuck its not to hard to reinstall the points RIC
R E L Lloyd

having points along has never been a big deal for me. There are few things worse than being stranded in nowheresville just because of not having a small, portable tool or part.

[I'm sure nobody here knows what i'm talking about...]
Philip

I've never had points or condenser fail in 35 years, and I have carried spares for most of that time. Who is going to carry a spare Ignitor? All it basically saves is having to replace the points every 10k or so, at the risk of total failure without warning at some point (ho ho). That and hiding some distributor problems, where you really should be dealing with the distributor itself. From some reports of fitting this or things like it you *do* have to mangle the points plate which makes retro-fitting points and condenser difficult if not impossible.
Paul Hunt

Philip,
I have the Ignitor I on my 78 B and have the Ignitor II installed on my 80 Spitfire, and I can see no performance difference between the two models. They both look and install the same and both versions seemed to improve the idle and performance slightly in both cars. My B has a Eurospec dizzy on it and the installation was as easy as removing the points and installing the Ignitor in their place. I have had a Ignitor I on my 66 Mustang for around 6 years and have never had a problem with it, yet I carry the old points and condenser in the trunk on all three cars just in case of failure.
R Slice

Phillip
I had a bad experience with the Pertonix unit I installed in my, not even run/broke in MGB engine.
Failed after running for 20 seconds. Well like any good mechanic, I blamed myself for incorrectly installing it. [We all seem to do that]
So I went over and over the installation instructions, called Pertonix and then Moss Motors to see what I'd done wrong.
Apparently nothing. [whew]
Moss graciously sent me a new unit, and a refund on the defective unit.
Installed very carefully and runs like a champ. [MGB's are champs ya' know]
Then after the Morris Estate arrived back from the La Carrerea Panamerica, [Mexican road Race] That my son Brian crewed for, the Second Strike, or MSD like with Rpm limiter needed a new home. And since I was owed some cash, it went into the autox car. ['77 MGB]

Even with just the Pertonix, the idle quality seemed better. Now with the Second Strike, definitely makes more power. And so much fun bouncing off the 6500 rpm limiter at an auto cross in second gear.

Grass Roots Motorsports magazine did a dyno/rolling road test coupla' years back. They determined that the Pertonix did actually give a 2-4 HP increase with a rubber bumper car.
Modern technology. Ain't it great?
Safety Fast
Dwight

Dwight McCullough

On the other side of Paul's arguement; the ignitor doesn't need constantly resetting as the dwell and thus timing varies as the points wear; the ignitor doesn't place a load on the dizzy drive or vary the ignition timing from lobe to lobe of the dizzy cam; idle is always smoother with the ignitor since each cylinder is getting exactly the same timing; and I have had points fail suddenly (physically broken.

So IMHO dump the points and go Ignitor - there is NO need to butcher the plate and retro fit is easy.

The same cannot be said about other electronic ignition systems which, again IMHO, offer little extra over the basic Ignitor.
Chris at Octarine Services

Chris has hit the nail on the head in that the dwell and therefore the timing never varies. My GT idles rock solid with the ignitor system and starting is always first time. I can't say that performance is better because I don't think it is. The downside of all this is that that the unit is so reliable you never go near the distributor so might tend to overlook the need for lubrication and maintenance of the advance weights.

The operation of the tacho can sometimes be a bit funny that's not really a problem
Iain MacKintosh

Iain,

In theory the performance ought to be better - the whole point in blueprinting an engine is to get each cylinder producing the same amount of power and variable timing works against that - you only have to watch the timing mark jumping about on a points equipped dizzy to realise that the variation from one firing of number one cylinder to the next can vary by a few degrees let alone the variation between cylinders!
Chris at Octarine Services

i find myself a little torn between two valid points of view. My car is a proper street B, with just simple 'everyman' modifications. I use it alot, though, and while points haven't ever failed me, i would like to get it running as smooth as possible. Plus, I have a tendency to 'fiddle' too much and EI will force me to avoid that a bit :) Don't worry Iain, I'll not forget to lubricate...

From what i'm gathering, the main advantage of EI is 'steadyness.' As you say, Chris, that is accomplished by the basic ignitor system. Simple is good.

Pertronix claims the ignitor II offers, higher spark voltage and 'automatic dwell adjustment.' the price difference is about 40$, minimal in the life of a distributor. But the unit's blanking plate looks different and i'd hate to get into the sort of mangling that Paul warns about. Besides why do they still make both? Then of course, there's the 'second strike' box that's been working for Dwight.

I'm hesitant to give up the retrofit ability and i'd be terrified of pushing the 6500 mark, so while i'll not be competing with Dwight at the autocross, I still want the most sensible upgrade. I or II?

Philip

We use an Ignitor II in our Vintage race MGB.
It works flawlessly in excess of 8000 RPMs.
I can not tell any difference in the Ignitor I which I had used for years and the II which I installed this year. I have found that if they are going to fail, they will do so in the first few minutes of operation, if they work after that I have never had one fail. I have had several that did fail the initial installation though.Pertronix has always replaced the faulty units for me. They seem very good to work with. I have also had problems with the rotor burning though, but I think this might have more to do with the coil. I change the rotor in the race car every race just in case.
Tom Whitfield
SVRA MGB
Tom Whitfield

Chris,, I can go along with that if there is wear in the dist and a lot of scatter in the timing, however the improvement will vary dependent on this and in my case I really can't say that I noticed a performance difference except for the fact that idling is very smooth even down to 500rpm. My roadster has points fitted and whilst it idles OK it suffers from this problem that when one HT lead is removed nothing much happens. Perhaps the electronic ignition might help this ??
Iain MacKintosh

Iain,

I see it in brand new 45Ds, with new camshafts and drive gears, there is a distinct variation in the timing.

My theory is that the drag of the points heel as it goes over the lobe of the dizzy causes the drive to "flutter" as the backlash is taken up and released.

This drag is totally absent in the electronic system so the drive is constant.

The fact that some cylinders have less effect on the idle speed is more due to mixture variation in the manifold than to ignition issues.
Chris at Octarine Services

Chris, I had always put that down to manifold distribution as well. I agree that there is drag created by the heel of the points and also a side loading on the shaft but it is hard to imagine that this minimal drag could affect the whole drive assembly. I'll have to fit EI on the roadster as well now. Thanks.

Iain
Iain MacKintosh

Well, since I started checking dwell instead of gap, I have never had to adjust points between changes on either the 4-cylinder or the V8.
Paul Hunt

To quote Phillip;
"I'm hesitant to give up the retrofit ability and i'd be terrified of pushing the 6500 mark, so while i'll not be competing with Dwight at the autocross, I still want the most sensible upgrade. I or II? "

OK Phillip, if MGB's came from the factory with a 6000 redline, and now I have the heavy duty valve springs, and a fully balanced engine, what is wrong with running them 500 rpm higher?
I limit my redline with the Second Strike rpm limiter.
I do need to drive this car back and forth to driving events, and want the engine to last for a few miles.
It will!
One of my friends who drove his '70 'B' to over 100,000 miles, and autoxed it regularly.
Hey, MG's are tough!

Oh by the way, the engine wouldn't even run with the original coil.
I had to install the Pertonix coil as well.
Safety Fast
Dwight

Dwight McCullough

The difference between the 2 setups are that the the original Ignitor I needs resistance in the coil and operates at 6V and the II needs no resistance and operates at 12V giving more sparking power as long as a suitable coil is used.
Mike MaGee

thanks mike:)

Dwight...there's nothing wrong at running it at 6500 if your engine feels fine with it. Heck, I imagine racers push 8000. I'm just jealous:)

Being a daily driver for a while now, I've driven my B for over 100k miles as well. That includes 2 cross-country trips and supension-killing NYC potholes. MG's are certainly tough. But Speed=$ and often trouble. If there's anything I hate, it's being stuck on a highway, furthering those @#$ cliches of bypassers going 'ah, English cars. they're always breaking down.'

Still, it's nice to see somebody passing the miatas and I salute you for it.
Philip

I installed a petroix ignitor about 12 years ago in my 1970 MGB-GT. The only time I had to adjust the timing was when I moved from Colorado to West Virginia. No more points or timing to adjust.

Actually it only take about 15 to 30 minutes to adjust.

Kermit Witherbee

Electronic parts tend to have long lives after a high rate of infant mortatlity. I've heard alot of stories of Pertronix that die in the first 5 minutes, replaced, and replacements live long and happy lives. Of couse, Pertronix should test them long enough to assure all mortality occurs before shipping- but that's a different argument.

Another option (off topic) for us boys in the US that may make sense is a Davis Unified Ignition. DUI just offered an MGB distributor using GM HEI guts, so you'll have no problem finding parts in the middle of absolutely nowhere Wyoming. There was a guy up in Oregon who used to build a similiar deal in the 90's but he drifted off into a 'Save the Collies' thing, and got out of car parts.
greg fast

"Save the Collies"?
MMD

It was some sort of group dedicated to saving some kind of dog- it obviously didn't make a huge impression on me.

While I applaud people who sacrifice for what they believe, well....
greg fast

You can get diode switch "electronic systems" for under $15 us. They work great. Nobody advertises them because they are so cheap. There are plans to build them yourself on the net. The diode closes the circuit immediately after the points open. When the points close the system is already charging and there is no juice carried by the points. If the system fails, just cut the one wire to the diode and you are back to the original system. These are often marketed as "dwell extenders". Points last forever and the spark is hotter allowing larger spark plug gaps and/or higher compression without plug problems. The modern transistor systems do the same thing but do their switching based on an an optical or magnetic signal rather than the mechanical opening of the stock points. Dual point distributors by increasing the dwell period increase the time for the coil to charge and produce a hotter spark. The diode closing instantly creates even longer dwell than a dual point system.
All coil based systems produce no more voltage than needed to creat the spark to jump the gap. At higher compression the voltage required to jump the gap is higher because the denser air acts as an insulator to block the spark. A low compression engine can operate relably with a weak ignition system with bad wires, rotor, cap, points, etc. Also, at higher speeds the ignition system voltage typically falls off because there is less dwell "time" to charge the coil, which results in high speed misfire. The higher the compression, and the rpm the more you need a high performance ignition sytem.
As a practical matter a 4 cylinder engine at 7,000 rpm is using the same ignition load as a v8 engine at 3,500 rpm. The MGB has low compression compared to modern engines. The stock system with an electronic set of points is more than adequate for all but all out race engines.
Barry
Barry Parkinson

Dwell extenders, like dual point distributors, are a waste of money on a standard B. Consider that the V8 has twice the number of cylinders and half the dwell time, a V12 three times the cylinders and one-third the dwell. These don't need them making them even less useful on a four cylinder.
Paul Hunt

Paul
The major advantage in my book is no point maintenance. You set the transistor or "dwell extender" ignition and forget it. No periodic messing with the points.
Barry
Barry Parkinson

Since I started checking points dwell at service intervals instead of gap I haven't had to touch mine between replacements either, and in fact I'm still waiting to do the first replacement which is now well past 10k miles. This is on a roadster and a V8. YMMV.
Paul Hunt

This thread was discussed between 22/11/2004 and 07/12/2004

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