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Pertronix Electronic Ignition Question

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HiPowerShooter Avatar
HiPowerShooter Gold Member James Booker
Oshkosh, Wisconsin, USA   USA
1973 MG MGB
So...what's this all mean in practical application? All the gobblygook is fine for those who find it interesting but most just want "real world" answers/application information.

Product A is better because....
Product B is better because...
It really doesn't matter in the application sense...



"One test is worth a thousand expert opinions"--Alvin "Tex" Johnston...Boeing test pilot.

73 MGB. Tires: Round, black, hold air. Oil: Sometimes old, sometimes new...always slippery. Oil filter: Yellow, usually full of oil. Carbs: 2 SU HIF. Distributor: Yes. Headlights: Not that bright but bright enough. A bunch of other stuff most cars have but not really important enough to itemize. Oh, wait...it has a cool sounding exhaust with stickers on the chrome tips. Really slays the ladies...

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ingoldsb Avatar
ingoldsb Silver Member Terry Ingoldsby
Calgary, Alberta, Canada   CAN
1971 MG MGB
Fred - thanks for doing some actual research.

If you ever get your hands on an Ignitor II, I'd be interested to know how it performs (and differs), both with a stock coil and the low resistance coil that Pertronix recommends.



Terry Ingoldsby
terry.ingoldsby@DCExperts.com

pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, Nova Scotia, Canada   CAN
My oscilloscope arrived today... maybe I can add some real data. I'm assuming Fred's data is from a test rig... maybe I can get some data from a running B series?

I just need to figure out how to use it. It came with zero instructions. Not a single shred of info on how to use it. Youtube to the rescue I guess.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

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pinkyponk Avatar
pinkyponk Gold Member Adrian Page
Berwick, Nova Scotia, Canada   CAN
In reply to # 3571180 by HiPowerShooter So...what's this all mean in practical application? All the gobblygook is fine for those who find it interesting but most just want "real world" answers/application information.

Product A is better because....
Product B is better because...
It really doesn't matter in the application sense...

They look pretty much the same to me... if you are lucky enough to get points and condenser as good as Fred tested. Fred's data does not show how the points setup will perform in 2000, 5000 miles etc. It slowly degrades... and the module does not. With the module you also get a bit of a pass on shaft bushing wear, so you might find a result more like the Grassroots article... where points were a bit behind the module if your distributor is anything less than perfect.

Adrian



Home built Eaton M62 Supercharger with 9psi boost, "stock" high ratio rocker arms, 8:1 compression, Piper 270 cam, ported head, matched manifolds, CB Performance computerized ignition.

Chas69 Avatar
Chas69 Karl Mynyk
Orefield, PA., USA   USA
1972 MG MGB
Most manuals can be found in PDF Format on manufactures web site for downloading.

Ex-Calif Avatar
Ex-Calif Gold Member Dan D
Cincinnati, Ohio, USA   USA
1968 MG MGB GT "Bart - Yellow And Naughty"
1977 MG MGB "Red Betty"
2012 Jeep Liberty "Tank"
2014 Hyundai Accent "Skate"
There is "better" and "noticeably better" - like all things automotive these can be angels dancing on the heads of pins (whatever that means)

If anyone could drive 3 MGs back to back and tell me which ones had EB and which ones had points I'd be amazed...

In reply to # 3571180 by HiPowerShooter So...what's this all mean in practical application? All the gobblygook is fine for those who find it interesting but most just want "real world" answers/application information.

Product A is better because....
Product B is better because...
It really doesn't matter in the application sense...



The goal - Reliable summer driver interspersed with mechanical tinkering...
Motto - "Driving fifty in the twisties..."
On Mods - It's your damn car - Do what you want. Haters gonna hate...
On SUVs - Drive your B like a soccer mom is texting her friends about how she wants to kill you...
Red Betty - http://www.mgexp.com/registry/GHN5UH418165
Bart - http://www.mgexp.com/registry/GHD4U146898G

Fred Winterburn Avatar
Ripley, Ontario, Canada   CAN
Dan,
-I would be amazed too if anyone could tell the difference between points and say a Pertronix 1. Except that the pertronix 1 might start a car better if the battery voltage was high, but the starter was weak, because the electronic switch opens quickly no matter how fast the engine is turning while points opening slowly waste more energy and give a weaker spark. But it would take the combination of a slow starter and a good battery to tell the difference and that combination is pretty rare (my Morgan is like that though, but the CDI on my car will provide a full powered spark down to 5.5V and slow opening points trigger the CDI just fine with no energy loss from it). Usually the starter being slow is accompanied by the battery being marginal, in which case as the voltage drops, the points system will provide a slightly better spark than pertronix despite the slower opening of the points.
-What rankles me somewhat is when installing a pertronix 1 or equivalent is called an 'upgrade'. To be an upgrade it needs to produce a quality spark, which pertronix 1 does not provide. It is weaker than a well sorted Kettering system, but it is not an upgrade if it's spark quality that matters. An upgrade should be a system that provides a better quality spark than the Kettering system it replaces.
-I had an interesting email today from a customer with a 71 Ford. Before fitting the CDI a year ago, his engine would not rev above 3800rpm. He thought it was the carburetor initially. With the CdI fitted he was able to attain the normal redline easily with more power throughout the rev range. In cold weather it was almost impossible to start and with the CdI it started like it should. Turns out one year later that he discovered his breaker plate had 3/16" side play, completely worn out. The CDI doesn't care about dwell or bounce, so it was making a spark every time. Pertronics would have masked some of that too, but not nearly as well since dwell could be affected. Pertronics is great for masking some shaft wobble though. I have tested that and it is true. The downside of a system masking a fault, is that the fault gets worse before it is repaired properly. The upside in this case with the Ford was that it proved it wasn't the carb. Fred

In reply to # 3571557 by Ex-Calif There is "better" and "noticeably better" - like all things automotive these can be angels dancing on the heads of pins (whatever that means)

If anyone could drive 3 MGs back to back and tell me which ones had EB and which ones had points I'd be amazed...

In reply to # 3571180 by HiPowerShooter So...what's this all mean in practical application? All the gobblygook is fine for those who find it interesting but most just want "real world" answers/application information.

Product A is better because....
Product B is better because...
It really doesn't matter in the application sense...



'Anyone who likes liver, can't taste it'
'If you want to repair car electrical systems successfully, learn Ohm's Law'.

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ArdsleyTank Peter Taylor
Dickson, Tennessee, USA   USA
1979 MG MGB "Henry"
If I may...

Back when I had a Pertronix, (which was about three weeks ago...), I had this annoying stutter and loss of power, accompanied by my tach going silly every once and a while...

Since I swapped my distributor to a 45D4 with points, it has been smooth sailing. No tach shenanigans, no stutter, just smooth as butter.

Not sure if that helps, but...

Peter

nickj Avatar
nickj Gold Member Nick Jenkins
Novato, Marin Co, CA, USA   USA
1970 MG MGB GT
1972 MG MGB
In reply to # 3571880 by ArdsleyTank Not sure if that helps, but...

Experience is always the best advice.

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Ex-Calif Avatar
Ex-Calif Gold Member Dan D
Cincinnati, Ohio, USA   USA
1968 MG MGB GT "Bart - Yellow And Naughty"
1977 MG MGB "Red Betty"
2012 Jeep Liberty "Tank"
2014 Hyundai Accent "Skate"
Spot on Fred - As always a great post.

I do not view EB as an "upgrade" - To me it is a simplification. Fewer variables and fewer moving parts (usually) translates to fewer failure points, easier troubleshooting and better reliability.

If one has EB and they suspect poor ignition performance then (duh) points gap, dwell, pitting, ground fault etc. can all be ruled out...

I also don't like bending low over the fender adjusting points.



The goal - Reliable summer driver interspersed with mechanical tinkering...
Motto - "Driving fifty in the twisties..."
On Mods - It's your damn car - Do what you want. Haters gonna hate...
On SUVs - Drive your B like a soccer mom is texting her friends about how she wants to kill you...
Red Betty - http://www.mgexp.com/registry/GHN5UH418165
Bart - http://www.mgexp.com/registry/GHD4U146898G

. Hide banner ads & support this website by becoming a > Supporting Member <

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