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Distributor problem [a bit weird]

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roscoe

roscoe

Jedi Knight
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I was in the process of installing a Pertronix ignition module in my BN2 and ran into a problem. The location of the post on the breaker plate does not allow installation of the Pertroninx module. The junk distributor I have on the shelf is a DM2 that has a different breaker plate and if it were in on the engine it would accept the Petronix module. So the question is, what do I have on the engine? More important to me is that this distributor is in good shape and has been problem free, I don't really want to change it. I've added some photos to show what I'm talking about. As usual I expect that the vendor I bought it from is not going to exchange it with me unless they are comfy that since I couldn't install it I didn't ever put power on it (I'm waiting to hear). I'd like to figure out what I have and order the correct Pertronix part. My installed distributor stamped data has the part number 40495A, which goes back to a DM2P4 as does the one on my shelf. Has anyone else run into this? The photo on the left is on the engine and the one on the right is showing the breaker plate I would need to use the Pertronix unit I ordered. Thanks.
MY Dist.jpgDM2.jpg
 
I have never answered my own post and I'm not sure it will work but does anyone know if I just need to swap out the breaker plate with the one I have on the shelf. That would make me happy and you'd all hear a big forehead slap.
 
Thank you Steve. Helpful, maybe yes,maybe not so much. His advice was to put the points back in as the Pertronix Ignitor (I) is not recommended with solid core wires and pointed out that the Pertronix web site noted that. It is true that the Pertronix Ignitor II has a caution note that due to the added electronic features such as self adjusting dwell etc. that the Rf interference caused by solid wires may well cook the Pertronix module. The Ignitor I is just a Hall effect switch and is not supposed to be as susceptible to this. There is some risk that Pertronix acknowledges but there are many folks who use it reliably with solid core copper ignition wires. My question about the breaker plates remained unanswered and they are not interchangeable.
 
Jon:
Please clarify what you mean by "Solid Core Ignition Wire "
Personally ,I did not think it was manufactured any more. ???
 
Keoke said:
Jon: Please clarify what you mean by "Solid Core Ignition Wire "
Personally ,I did not think it was manufactured any more. ???
Click to expand...

Pretty sure he means 'stranded copper wire' core ignition wire. I use the term--'solid'--myself sometimes, but of course the wire isn't solid (well, the individual strands are). Many vendors carry it; it's not illegal (yet).
 
Yes, what he said. Copper wire with just the resistance of the copper strands.
 
steveg said:
FWIW I've been using the Pertronix 1 with copper stranded wire for years. I use a non-advancing old-style Sears timing light and it works perfectly.
Click to expand...

Yep Me TOO Steve:

But would you believe it acts up sometimes when i use my more expensive Snap-On light encased all in pretty red plastic.:highly_amused:
 
Bob_Spidell said:
Pretty sure he means 'stranded copper wire' core ignition wire. I use the term--'solid'--myself sometimes, but of course the wire isn't solid (well, the individual strands are). Many vendors carry it; it's not illegal (yet).
Click to expand...

Please note:
Shakespeare is not valid in this case.-:highly_amused:
 
So, I got my question about the distributor answered and some of you probably already know this but there were two styles of 4 cylinder DM2P4 Lucas distributor. An early style with 2 piece contact breakers and a late style with one piece. They have different breaker plates and the vacuum advance connection to the breaker plate is different between them. This info is actually on the Pertronix application guide. I'll be getting the correct Pertronix unit soon. I did speak to a Pertronix rep about this and he did in fact say that although it might work just fine and last a long time, they no longer recommend using any of their Ignitor trigger units with copper wires. That having been said, they have not changed their application guide one iota. I'm willing to take the chance (thank you Keoke and Steve). If I can do it without too much ugliness I just might shield my wires with some braided stainless tubular shielding I happen to have a bunch of. At the least I'll put in some new copper wires because aged, work hardened copper aggravates the Rf issue.
 
I don't know if it makes any/much difference, but I've always used Pertronix and stranded copper secondary wires and resistor plugs. The plugs are a resistance load (duh), and spiral-wound suppressor wires would probably be a somewhat inductive load and it might make some difference.
 
I'm willing to take the chance (thank you Keoke and Steve). If I can do it without too much ugliness I just might shield my wires with some braided stainless tubular shielding .

Jon:

Your thoughtful approach here is valid,

However, DIY shielding of the leads [Particularly with SS material] may simply add to your problem.

Consequently , The use of resistor type Spark Plugs and Bosh Suppressor connectors at the plugs probably is a more realistic approach to a solution.
 
Each resistor element creates approximately 5000 ohms resistance. Therefore either the wire, cap or plug should be resistor, not more than one of those.

I don't have a radio, so no need for any resistor element. Better for my somewhat tired engine that way.
 
steveg said:
Each resistor element creates approximately 5000 ohms resistance. Therefore either the wire, cap or plug should be resistor, not more than one of those.

I don't have a radio, so no need for any resistor element. Better for my somewhat tired engine that way.
Click to expand...

I run a stock looking radio however it is programmable [AM & FM] and of relatively high signal sensitivity.

I also run on both my BJ8's Bosh connectors at the plugs and Bosh WR7dp Plugs'
with out a minutes trouble in engine performance, Radio Off, or EMI Radiation from the ignition.
Similarly, the system is not sensitive to external radiation either.
 
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