Some Chrysler Distributor Information and Maintenance

I apologize that these links are not marine specific. However, I feel they may (or may not) offer useful information for repair and maintenance of these older OEM distributors.

First things first!
Automotive Ignition IS NOT A Substitute For Marine Applications.


So this is a " for what it's worth " thread. I assume no liability.

A word of caution:
Read the article first. Make sure you know exactly what you are getting into.
Before you loosen the distributor hold-down bolt I strongly recommend you mark everything.
A digital camera will be useful to help you remember "how it was" before any disassembly.

Starting with a timing check to know where you started from, document your readings. Write them down, then double check them.

Rotate crank damper to 0° (zero degrees) or TDC on the compression stroke. Careful, some dampers could have marks on them 90° apart. The rotor (dizzy) should be pointing to the #1 plug tower of the distributor cap.

Marking the distributor base and the block prior to removal is a good idea for reference on reinstall.

The advance springs may be the same or in fact different. One could be heavier than the other, longer than the other, or whatever. Make sure you document their position before removal.
Don't over stretch the springs when removing or installing. "Just enough" to get them off and on is all you need.

The advance plate may or may not have a number on the bottom face. If it does, that is the total mechanical advance degrees the two slots provide (degrees at distributor) for that distributor.

I see some marine suppliers are replacing Chrysler Part #2586576 advance spring set with Mallory 9-26804 advance spring kit.


The links........................

http://www.classicwinnebagos.com/forum/index.php?topic=3424.0


http://www.hotrod.com/how-to/engine/mopp-0301-mopar-electronic-ignition-system/


an advance limit plate.............

http://www.4secondsflat.com/Mopar Mechanical timing limiter plate.htm

Once again:
Automotive Ignition IS NOT A Substitute For Marine Applications.

Right on! Ditto automotive starters and alternators.

Jeff

Dave, if I may chime in.

Not only is the automotive ignition system un-suitable for Marine use (due to USCG regs), the vacuum advance serves no purpose, and the automotive advance curve will be incorrect for Marine use.
If we were to use the automotive advance curve, and if that curve was too agressive for the Chrysler Marine Engine, we risk detonation damage.


Flyweight return spring replacement:

As we all know, the flyweight system controls the degree of advance and the advance curve. The return springs play a huge role in this.
A slight change in the spring value can make a large change to this curve.
Keep this in mind if you are thinking about replacing return springs!

If you are replacing them, I would highly suggest that the distributor be run on an old school Sun, Allen or King machine as to verify the flyweight system function and the advance curve.

But here's the catch:

No one to date here has been able to find a Chrysler Marine ignition advance curve graph for any Chrysler Marine Engines. I have personally called Mallory and they were not able to show or send me a curve graph.

Given that we still don't have a Chrysler Marine Engine advance curve to use while calibrating the flyweight system, where do we go? :rolleyes:




BTW, Chrysler pioneered VR back in the 70's for their cars/trucks. VR is a great triggering system and it made it's way into the Marine world. Mallory has used VR for many years in their YLM marine series.

If you now have a VR system, I'd stay with it, unless for some reason the system has gone bad beyond repair.




.

All advance in by 2,500 to 3,000 rpms is all you need.

Jeff

First of all, I'm not posting to this thread to get a rise out of anyone, nor to start an argument.
A good debate... sure, if it's done politely!

I want all Chrysler Marine owners to see good performance and long hours from their engines.
I don't want to see anyone suffer engine damage!

fastjeff said:

All advance in by 2,500 to 3,000 rpms is all you need.

Jeff

Click to expand...

Jeff, as discussed, no one to date has been able to find Chrysler Marine's ignition advance specs that have been laid out in terms of numbers that can be seen in graph form.
We can find BASE or Initial advance specs all day long.

As we know, both numbers are necessary in order to check and see just what the ignition system is doing in the progressive range and TA.

Look at this Chrysler 318 info for a moment! Can you make any sense out of it?
I can't!



It's great to know that @ 2,500 to 3,000 rpm we can be "full in", but what's missing is the full in advance data.
IOW, what is the advance in degrees suppose to be @ 2,500 to 3,000 rpm?

IMO, if we don't have both numbers, the info is rather meaningless..... yes/no?

Examples:
Let's say that the BASE advance is 6*.
Let's say that we know that the full in RPM is 2,500 to 3,000 (I'd still like to see this via a Chrysler Marine spec sheet).
Let's say that the owner's ignition system advance is worn and is offering 29*.
If he adds in BASE advance of 6*, he ends up with a TA of 35* @ 2,500 to 3,000 rpm.

I will tell you that 36* @ 2,500 rpm is a potential recipe for detonation.

To be fair:
Let's say that the BASE advance is 6*.
Let's say that we know that the full in RPM is 2,500 to 3,000.
Let's say that the owner's ignition system is worn and is offering 25*.
If he adds in BASE advance of 6*, he ends up with a TA of 31* @ 2,500 to 3,000 rpm.

I'd still think that 31* @ 2,500 rpm is risky!

And this doesn't even address or acount for incorrect flywieght return springs, nor rust compromised flyweight return springs!

So in essence, aren't we are back to the drawing table again?


**************************************

Rhetorical questions:

How many owners have experienced piston damage and/or valve damage, and have just chalked it up to bad luck?
How many owners with the above scenario have actually considered that Ignition Induced Detonation may have played a role in this?



To those reading this thread, I'll suggest that when we set ignition advance, that we not only set/adjust for BASE, but that we take it further and also take a good look at what the progressive and TA are doing!

If this wasn't so important, we'd just simply set BASE advance and walk away.



.

One thing that's working in our favor is that the motor was designed to run o 86 octane fuel (per my owner's manual). Seeing we use overpriced 89 octane marina fuel, that allows a few more degrees of advance. In my boat's case, the motors are not working hard at all, so that too allows a bit of leeway.

Jeff