Re[2]: {Chrysler 300} Elementary ignition question

Back on wire positions, what threw me for a loop at first was the setup on the G I bought two years ago. P.O. had converted to MP electronic setup with new custom engine wiring harness form the late Greg Leggatt - Mopar electronic VR, dual field square back alternator (like 1973+), and mechanical tach drive racing distributor with no vacuum advance. The electronic VR and dual field alternator setup arguably actually a plus (but not stock), but racing distributor with no advance dumb - terrible fuel economy, fixed mechanical advance too, G is not a race car! But what threw me is PO had wires 180 degrees out - number 1 was where number 6 should be! Resulted in "cleaner" wire routing appearance (but not stock). No vacuum can allows flexibility in what tower is #1 - no vacuum can in the way for distributor positioning! Fix is easy to get correct wire routing - just pull distributor and rotate the rotor 180 degrees, reinstall, and move all wires on towers so #1 is 180 degrees opposite - where it should be! Again, engine doesn't care where wires are on the towers as long as firing order/rotor correct. As the original G dual point distributor was long gone, and I didn't have a spare, I just got a new electronic one on ebay from Rick Ehrenberg (good unit , uses MP orange box or his own box, made in USA, clone of original Direct Connection design from 1980's!). No tach drive, but at least I get vacuum advance, much better fuel economy (relatively speaking - it's a ram!) Also, got a correct wide-fin 1961 alternator for correct appearance, had local old-school starter/ alternator shop rebuild it and convert internally to dual field (not difficult btw, or expensive to do). Retains stock output (35A?) unlike the new ones which are 60A+!

agree ! — wow Carl ,
that is REALLY valuable info from a guy that has obviously been there . I did not know the relationship of points opening and rotor position varied so much within the body machining of various distributors ( and thus the clip location and in turn which tower is #1 !
I have encountered this in many flavors over the years and blamed myself ( must be oil pump drive is off one tooth etc) — and you really do not want to revisit that , so moved wires . Maybe why mopar had the red end (!) Not always the same tower across distributors…

On another related front , I have been working for a year on an electronic circuit that “ closes the points “ electronically , right after the spark far faster than the second set in a dual point . So single point (or dual with second removed ) will gain dwell ( and 1000 + rpm more before falling off—- , improved due to dwell increase at high rpm ,( ,why the 300 has dual points- they had same goal )
Are you aware that all electronic ignitions lose 1 volt in transistor,
so net V to coil set up is say 12V instead of 13 , but energy in coil goes as 1/2 L I sq . 12 sq is144 , 13 sq is 169 , huge difference (the max current follows voltage) . Points make a hotter spark than any electronic (!) by a lot . Why John commented it runs great on single point , and rams pre JK no point going over 5 k . But single point spark energy starts dropping at about 3500,,still ok , but dropping as dwell time shortens
But hemi another story , loves hi rpm hp , needs the spark . Had duals in 51!
The problem with points is dwell is getting too short at high rpm for coil to “ fill up “ ( takes about .002 sec) . We are gonna fix that
Better than dual points , while still keeping points ( so no punting common to full electronic either )

Most 300 dual point are not set right in my experience (in my own 300’s)

really hard to get right with gap measuring it moves as you tighten it , HAVE to use old style dwell meter . ( sears on e bay)
Get it wrong it runs awful . Fighting with that hassle in back with hemi is my motivation ( aka dropped screw)

Hope you do like the idea! will fix all single point any brand.

soon , little box outside dist ! 6500 rpm no problem w single points , and no arc when they do close ( circuit is already closed!) No electronic pickup or mods either
On Aug 1, 2025, at 9:16 AM, John Nowosacki <jsnowosacki@xxxxxxxxx> wrote:

Thanks for this explanation, Carl! Earlier this Spring I removed the dual point tach drive disty from my G to send away for rebuild, and purchased an inexpensive single point unit off of Rock Auto to use temporarily. I was being very careful noting where the rotor was pointed and at which spark plug wire tower as I switched distributors. I was surprised/confused while making the swap when I noticed I would have to have the plug wires 'offset' by one tower on the replacement single point unit as compared to the original dual point. I didn't bother to try and understand why, so I just put the wires where they needed to be and the engine fired right up and ran fine. I'm going to have to reverse the thought process when switching back to my now rebuilt original distributor. I must admit I've had my original back for some time now, but the car is running so well on the cheap $99 Rock Auto replacement (came complete with points/condenser/rotor/cap installed for that price), I haven't rushed to put it back in. Part of the procrastination was in trying to remember the direction of the 'offset' when I made the original swap, and not wanting to mess up and possibly go in the wrong direction going back to the original. Your post explains what I encountered and has helped to refresh my memory so I can more confidently go about re-swapping. ;-) It will be nice to see my tachometer working again in the console.

On Thu, Jul 31, 2025 at 8:25 PM Carl Bilter <cbilter@xxxxxxxxx> wrote:

Didn't work as in doesn't start? Tach drive distributor (F I assume?). Still breaker points, correct? I have found that on this dual point distributor the #1 wire would go on the distributor cap tower that is the second one clockwise from the clip that holds the cap on. Looks like it's attached one tower clockwise (like a single point distributor or an electronic ignition, which has the vacuum can at a different angle than on the dual point). The engine actually doesn't care where the wires are on the cap, as long as the firing order is correct and aligned with the rotor properly. With the tach drive distributors you have to get the vacuum advance can aligned such that it is somewhere between the ram and the radiator hose. -if you are off by one tower in either direction (but correct firing order), the vacuum can will either be way back by the ram (retarded) or cocked way over to the right (advanced) and maybe hitting the radiator hose or the tach cable stretched too tight.. So, once you get the rotor in proper position for #1, figure out which is the best tower to start with #1. Sometimes two towers clockwise from the clip works best for positioning #1, but YMMV. Also, if someone installs a Pertronix electronic module inside one of these dual point distributors it will change the timing a lot and may require moving all the wires one tower clockwise. Make sure to set timing with vacuum advance disconnected and plugged - makes huge difference! - on G vacuum advance all in at idle!

Carl B.
G and J

------ Original Message ------

From "'Jay Williamson' via Chrysler 300 Club International" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>

To "John Grady" <jkg@xxxxxxxxxxxxxxxxx>

Cc "club chrysler" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>

Date 7/31/2025 1:42:08 PM

Subject Re: {Chrysler 300} Elementary ignition question

Well, that didn’t work. Grrr

I put my timing at top dead center so I could look at the rotor and see where cylinder #1 is. From that, I placed plug wires popped off #1. Going on the rotor turning counter clockwise, I placed plug wires #8 to the right of #1. Then followed the rest of the order according to the manual. The only difference is that I have a NOS cap on. What could I have wrong here. I am pointing to where I placed #1 wire.

Thanks for any guidance

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