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Why points are better than Pertronix... since u asked

Posted by B-racer 
B-racer Avatar
Jeff Schlemmer
Minnesota, USA   usa
1950 Willys Jeep Pickup "Ratrod"
1955 Chevrolet Thriftmaster
1958 MG magnette
1971 MG MGB "POS"
1973 MG Midget MkII   → more

In reply to # 2311753 by ohlord Pertronix 30 month warranty. 15000 rpm capable adaptive spark timing at high rpm,1/4 degree timing accuracy,Adaptive dwell maintains peak energy throughout the entire RPM range. Twice the spark voltage with the FT2 coil.
Are you guys stuck in the stone ages? Still using a tube radio in your dash? Running points in your modern driver?
having run a 25D distributor with points on a distributor machine and then installing a pertronix the accuracy was way beyond the point set. And it was a good distributor to start with.
For the purist fine,for someone that drives their B over 10,000 miles a year the pertronix beats points hands down.
You set your timing advance just as you normally would and you can advance it if needed for special tuned engines.
Anyone that complains of looseness ever read the PDF installation sheet?

Your post is why one could say Pertronix advertising is successful. Unfortunately, its not the way things really work. Yes, there may be more energy "available" but the car only needs about 12K volts to run exceptionally well, and unless you gap your spark plugs at .100", you can't produce that kind of voltage. The high quality Igniter II coils made in China or Mexico also won't last but a few sparks under those circumstances. If you wonder why, just ask Pertronix about the company wide coil recall that happened 9 months after I called and complained about coil failures using their product.

The TR6 that made great power actually had no other issues. It was an anomoly for sure, but a great example of a car that ran really well with 99 hp at the rear wheels, but ran exceptional on points. Jack's right when he says most of us will never have our cars tuned the way they were meant to be, because we're happy with the the way they run now and don't want to spend the time/money to get everything out of it we can. Unfortunately, that means the cars won't last as long, running in a mediocre state of tune, some since brand new.

IMPORTANT: The one factor I forgot to mention is RFI noise. If you run a side-entry distributor cap (pre-68 cars) with copper core plug wires, the RFI noise those wires throw off actually blind an electronic ignition from sensing its own signal, randomly. Even with really good plug wires like MSD, Cobalt, or Magnecore, there is some RFI present that can cause a rich misfire from time to time. This will show up as a rich spike on the dyno or a clear misfire on a scope, and causes a significant loss of power. Again, 5-40%. In once case, a TR4 wouldn't run any higher than 1200 rpms before dropping completely dead. Simply changing to a top-entry cap and carbon core wires on that car helped significantly, allowing the car to run with misfires. Adding points cleared it up 100%, as tested in my own personal car and repeated on the customer car in Washington.

Yes, Crane and Allison can have similar issues, but to a lesser extent with healthier electroncis and an optical sensor. The CEI system is great for a daily driver but has an entirely different set of issues due to the way the sensor picks up the signal, and isn't suited for regular use over 5000 rpms.



jeff@advanceddistributors.com

B-racer Avatar
Jeff Schlemmer
Minnesota, USA   usa
1950 Willys Jeep Pickup "Ratrod"
1955 Chevrolet Thriftmaster
1958 MG magnette
1971 MG MGB "POS"
1973 MG Midget MkII   → more

I have a scope I can hook up and run points/electronics on, but the screen is horrible on it (let's face it - scopes are OLD) and its very difficult to read even in perfect lighting. Unfortunately, a photo would simply be worthless. On the other hand, and air/fuel meter WILL show the difference, with a clean even signal versus rich spikes on a system that isn't performing well. I ALWAYS see rich spikes with a Pertronix.

Now in TR6s, the Pertronix kit is made wrong and distributor phasing is out of spec. In the case of the one I quoted above, I had modified the distributor for better phasing so that was out of the picture. The engine builder, dyno owner, and myself were all shocked at the performance increase in the car on points. Literally, it was ONLY a change in triggers that cleared up the car. Everything else stayed exactly the same.

As for dwell, that is another big issue. With points, you have slop in the breaker plate so it can rotate, and that play actually changes point gap at high rpm, which means a change in dwell. I theorize the change in dwell actually helps points perform better than a programmed Pertronix, always fixed at 60 degrees, which actually isn't optimal anyway. I find 57-58 actually runs better. It s a small change, but one you can't make with a Pertronix installed. I could write a book on my experiences with tuning distributors, and tuning engines to run better by simply modifying/controlling the timing but even I'd be bored to death reading it and wouldn't make it past the first few pages.

Sorry for droning on...

BTW, I don't expect anyone to believe me unless you take the time to try points and a full tune-up yourself. Then you'll see why you should have run points all along, unless you really can't/won't adjust points. In that case, electronics are for you!



jeff@advanceddistributors.com



Edited 1 time(s). Last edit at 2013-03-13 07:55 AM by B-racer.

mowogman Avatar
Bryan Frazier
NC, USA   usa

I would be curious to see a graph showing how they compare through the entire rpm range. If one was stronger at say 2500-4500rpm that would be more beneficial to a street car than if they other one only produced more power at WOT.

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underdog Avatar
Jim Underwood
Pittsburgh, USA   usa
1972 MG MGB
1980 Triumph TR8 "Fabulous Trashwagon"
1999 Chevrolet Corvette "Darth Vader"
1999 Chevrolet S10 "Spare Change"
2003 Jaguar S-Type "Eleanor"

I'll admit I have no personal experiance with a Pertronix. I have heard rumblings about some failures. I have used and know others with the old Crane /Allison shutter wheel setups that seem to go forever. 39 HP gain switching back to points?? I'll have to tell my drag racing buddies about this. I'm sure they will be clamoring to ditch their Mag Pickup Dizzys and CD Ignition Boxes.eye rolling smiley

pinkyponk Avatar
Adrian Page
Berwick, Nova Scotia, Canada   can

In reply to # 2311981 by underdog I'll admit I have no personal experiance with a Pertronix. I have heard rumblings about some failures. I have used and know others with the old Crane /Allison shutter wheel setups that seem to go forever. 39 HP gain switching back to points?? I'll have to tell my drag racing buddies about this. I'm sure they will be clamoring to ditch their Mag Pickup Dizzys and CD Ignition Boxes.eye rolling smiley

Exactly. I could have saved a ton of time not bothering with installing a supercharger.

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gooser Avatar
Drake Myers
Danville Va, USA   usa

In reply to # 2311960 by Wray You know what they say about opinions, but it's funny watching some of you guys trying to second guess Jeff Schlemmer, someone who has more direct experience and expertise in this area than anyone on this board, and one of the brightest guys I've ever met.

and he knows how to throw a party.

pinkyponk Avatar
Adrian Page
Berwick, Nova Scotia, Canada   can

Here is a link to a test of 3 types of ignition systems including points. There's even a big ol' chart to look at. http://www.carcraft.com/techarticles/ccrp_9812_ignition_performance_test/viewall.html

It corroborates Jeff's claims of points being capable of producing more hp than electronic ignitions. I had no dispute with that... although 2 or 3 hp more (sometimes less...) on a 400hp engine is not the same as 3 to 10 hp on a 90 hp engine. It's also so close among all three systems tested as to be considered virtually the same whatever ignition you use. (Will the points keep up as they and the distributor wears?)

It's the 39hp claim that doesn't wash. Something else wasn't noticed there... a stuck point plate, a leaky plug wire... who knows? Was a second Pertronix tried at the time to see if it was a defective unit?



Edited 1 time(s). Last edit at 2013-03-13 11:43 AM by pinkyponk.

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LaVerne Avatar
LaVerne Downey
Fruita, Colorado, USA   usa
1952 MG TD ~ For Sale ! ~
1954 MG TF "Green Hornet"
1969 MG MGB

My 20 year experience with the Crane on my MGB is all positive. 6 years with a Pertronix on the TF ...not so much. First of all it is wired funky to accomidate the positive ground. When setting up the static timing I found that test light turns off during the firing phase...would have been nice to know that before hand instead of discovering it on my own. A side effect of this is although you might carry a points plate with you (and I do) it's not a simple swap and go. The wiring has to be reversed and the dizzy retimed so you better be carrying a test light and a clamp wrench with those points.
The collar is a very very tight fit on the shaft, so no issue there but it does cause the rotor to sit to high so that has to be addressed. I understand the new units are triggered with the dizzy lobe instead of a collar but I have no experience with those.

Last year I noticed that the TF wouldn't fire while cranking the engine but fired as soon as I let go of the starter.I thought I might have a voltage drop in the ignition wiring so I bypassed the ignition wiring and wired it direct. That fried the unit...I can't think of any reason why it would , but it did. Battery was going away and had to be replaced about a year later but the bottom line is even if you have enough juice to crank the engine just fine, at some point the voltage isn't enough to trigger the unit. Seems rather odd to me. I replaced it with another Pertronix but found out later that the Crane will work on the TF and I wish I had bought one of those instead.

On the flip side I have points in the TD. I drive it rarely, may sit for months on end. Several times when I get in to go it won't fire. Same problem...over time the points oxidize just sitting there and I have to clean them before I take off or take something else and fix it later.
I remember back in the 70's that it was common to carry a couple of replacement ignition modules in your glove box if you owned a Dodge/Chysler . The Crane was a good fix for the Lucas crappers at the time as well. I like the idea of the electronic fire reliablity but clearly we aren't getting that at 100 bucks.

Speedracer Avatar
Hap Waldrop
Greenville, SC, USA   usa
1967 MG MGB Racecar "The Biscuit"

Jeff, you know I was already sold on your points and rotor button vs Petronix, I always though Petronixs is a mickey mouse set up, if one wants to go electronic, go big, spend alot more money, or go home, and for me on street car, it would always be a rebuit Lucas by you with your points. thumbs up



Hap Waldrop
Acme Speed Shop
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Performance Street/Race engines- modified heads, and DIY engine rebuilt kits
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Ralph 7h Avatar
Ralph Siebenhaar
Viersen, Germany   deu

I'm very satisfied with the points on my Mg's for nearly 40 years now. Only the V8 was changed to a Piranha/Newtronics optoelectronic black box system that worked better than the OEM one.
A few years ago, I tried Pertronix in on of the B's and it failed within a few weeks. Went back to points and all works as it should.
On an other B (also with points), I still have one of the Thyristor ignition switch boxes that were common in the late 70's and early 80's. The dizzy is still on points but the currant they have to switch is only some Milli-amperes. The Thyristor box takes the currant instead. It even has a switch to select points direct, points electronically assisted and an off position as an immobilizer.
On the attached pic, the box can be seen aside the coil.
I'm wondering if this stuff is still available.

Ralph


Attachments:
004.JPG    41.2 KB
004.JPG

ingoldsb Avatar
Terry Ingoldsby
Calgary, Alberta, Canada   can
1971 MG MGB

Quote: 25D or 45D ignitor2 with adaptive dwell. with flamethrower 2 45k volt coil

Okay - before we go any further - are we talking Ignitor I (fixed dwell) or Ignitor II (variable dwell). And what did Moss sell me several years ago? I'm going to have to pull the cover off my distributor and look it up.

The Pertronix catalog is at http://www.pertronix.com/catalogs/pdf/ptx/2012/Pertronix2012.pdf

Jeff - have you compared Ignitor I vs Ignitor II? The variable dwell feature should provide a measurable benefit. Also, voltage is not as important as energy. I agree that the plugs probably fire at less than 10 KV - and once they fire they clamp the voltage. However extra energy can make the spark hotter and better able to ignite the mixture under adverse conditions.

I've got to check if I have the LU142A or the 9LU142A. If it is the former, then I will likely switch to the Ignitor II and keep the Ignitor I in my battery box as a backup.



Terry Ingoldsby
terry.ingoldsby@DCExperts.com

JoeReed Avatar
Joe Reed
Cordova, Tennessee, USA   usa
1978 MG MGB "Kermit"

Interesting that some people apparently carry spare points with them. Why? Maybe it's just because they're so small it's no problem. I'm 64 years old and I've never once had an issue on the road that required a change of points. Had one condenser fail suddenly, but never a sudden points issue.

I also prefer to yank the distributor out and gap the points on the bench. I find it's quicker and easier to do it accurately that way. Having poor eyesight doesn't help...and it's awkward to be fiddling with holding the feeler gauge, keeping the gap correct and tightening the screw while bent over the wing with the bonnet prop rod partially in the way.

Many, many years ago I had a handy little tool that I wish was made for our distributors. It was just a set of rings sized to fit the common US distributors. To set the points, you'd just open the points....drop the ring over the distributor cam....release the points - and adjust them so that the gap was closed. When you removed the ring, the gap was perfect every time. They came in real handy when setting the points on a car where the distributor was in a bad location (think Chrysler slant-6!). Of course, the best was probably the GM distributors where you could adjust the points from outside the distributor using a dwell meter with the engine running...




79mgbv8 Avatar
Gil Price
Constable NY, USA   usa
1971 MG MGB GT
1976 MG MGB
1979 MG MGB V8 Conversion "Rumble Bee"

Hap X 2

I have had 2 Petronix failures that compelled me to seek a better solution --2 25D dist rebuilt by Jeff with points and no problems since in about 5 years. I tried to install the correct Petronix on my Ford V8 distributor and it would not even start --points lasted only 5-6000 miles so now have a Accel electronic module that lasts about 30 k miles. Petronix said nothing was wrong with the unit I sent back --its on the shelf in my shop... Jeff is the man

ltelencio Avatar
LARRY TELENCIO
Naples, FLORIDA, USA   usa

Hap X3

Have benn running Jeff's dizzy for five years, still great!

Larrysmileys with beer

riley1489 Avatar
Bruce Hopgood
Great White North, -, Canada   can
1953 Jaguar XK120
1959 Riley 1.5 "King George"
1973 MG MGB

I currently have 2 B series powered LBC that are using distributors that have been refurbished by Jeff, I have no intention of going away from points, the approach is simmple, inexpensive and being a bit of a 'dinosaur' I can mend them on the side of the road if needed, (never been there!). My mind is made up so don't try to confuse me with the facts.

Take a look here, how one chap sorted his B series engine ..............

http://retrorides.proboards.com/index.cgi?board=readersrides&action=print&thread=37297

Bruce

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