Logo

prestolite dist springs

I'm sure that Mr. King, Mr. Allen and Mr. Sun all began with something very similar to that.



You can acheive the same results on-egine by using a full array of degree markings on either the flywheel or the harmonic balancer.
The timing light can just as easily read #2, 3, 4 thru #8 cylinders, as it can #1.
In fact, you could strobe using the high tension coil wire for the timing light triggering sensor, and probably strobe all 8 cylinders.

But... these guys wanted an easy method for watching, plotting, adjusting, etc.
And what better way than to have the distributor at bench height right in front of you, full RPM control, etc?
Stop... reach in... adjust... start..... watch... stop/adjust again, etc.
Very cool.

These men were truly pioneers in this industry.
.
 
Can't wait until someone finds a source for the Chrysler Marine 318 advance curve....I've searched the internet with no luck :confused::confused::confused::confused: Running new Pertronix distributors with a factory curve of (about)5@1000, 11@1500, 18@2000, 25@2500 (all in). I've attached the file for my Pertronix to show spring curve set up.

Need to chart curve with my advance timing light to confirm advance....What I really need is the OEM Chrysler advance curve....but :confused: :confused: :confused: :confused:.

Crossing my fingers and taking it easy around the lake until I get better info for the correct curve. :mad:
 

Attachments

  • billet.pdf
    135.5 KB · Views: 100
Sorry; I was speaking of outboards.

One CAN buy a set up to eliminate the distributor's ignition function, however: It uses a magnet in a plate attached to the damper pulley and a 'black box' to administer the timing. The distributor is used to send the sparks to the plugs and run the oil pump. Common drag racing set up.

Jeff
 
Can't wait until someone finds a source for the Chrysler Marine 318 advance curve....I've searched the internet with no luck
Running new Pertronix distributors with a factory curve of (about)5@1000, 11@1500, 18@2000, 25@2500 (all in). I've attached the file for my Pertronix to show spring curve set up.

Need to chart curve with my advance timing light to confirm advance.... What I really need is the OEM Chrysler advance curve....but .

***Crossing my fingers and taking it easy around the lake until I get better info for the correct curve.
Yes, you sure do need to do this!


I too wish that someone would find an OEM advance curve for both the 318/360 and the 440 Marine. I find it hard to believe that Chrysler has not provided this somewhere.
How the hell to you properly set up a Chrysler Marine engine without this information???? Dang! :mad: :mad:


My take on your numbers, although I'm much more into the Chevy's:

5* @ 1,000 rpm would be BASE or Initial only.
We should see no mechanical advance prior to 1k rpm. There's no need for it.
If we see the mechanical system begin to advance much below this, we call also expect to see irratic idle rpm in some situations.

11* @ 1,500 rpm is reasonable.


18* @ 2,000 rpm is a 7* increase in only 500 rpm.


25* @ 2,500 rpm (all in)
IMO, I see no issue with the Full In of 25*, but full in at 2.5K rpm seems a bit early to me.
2.5K RPM is a prime RPM for marine load detonation.
I'd say to use caution if tossing 25* in at 2.5K rpm.


NOTE: Any timing specs, or flyweight spring recommendations, that show an illustration of an automotive distributor with a vacuum diaphram advance unit, is most definitely an automotive curve and information.
Again..... use caution.

***Automotive street performance engines pass through the RPM (where detonation is a potential) rather quickly.
In our marine scenarios, we have a potential of holding at this RPM much longer (i.e., higher cylinder temperatures).
Add to this that at 2.5k rpm, must boats are not yet at planing attitude, so engine loads are excessive.
IOW, either travel at hull speed, or get her up on step and avoid holding at this lower rpm range for any duration.


I've posted just lately in two different threads (different forums) where the guys engines suffered from detonation damage.
In both cases, neither mechanics bothered to check what the ignition was doing prior to tear-down.

BTW, both were SBC's using the silly full dished pistons. :mad:

.
 
NOTE: Any timing specs, or flyweight spring recommendations, that show an illustration of an automotive distributor with a vacuum diaphram advance unit, is most definitely an automotive curve and information.
Again..... use caution
I purchased the Marine approved version (they use same directions:confused:)

Ricardo,
What would your WAS (wild %$# guess) be for my engine ('85 318) curve? (since that's all we have. Thx Chrysler Marine:mad:

I have a few set of springs that came with the new Marine Pertronix distributor http://www.pertronix.com/prod/ig/flame/dist/billet_marine.aspx#MarineESTDistributors

Spring chart for Pertronix here http://www.pertronix.com/support/manuals/pdf/billet.pdf

Mix and match springs to get curve that I need using advance snap on timing light. :D
 
Last edited:
Let me chime in here since I was involved in this thread earlier. I am having no luck at all finding the correct numbers for the 440. The guy with the distributor machine who is going to spin mine cannot find anything either. I have made many stops at some old line marinas who were once Chrysler dealers and all I can get is the "deer in the headlight looks" when I ask the question.
 
chrysler 318 advance curve.jpg

Dave Hurrikain of http://www.hurrikain.com/ was kind enough to send this to me. What do you guys think:confused: The second set of part numbers is for a Chrysler Marine '74-'84 distributor. We may FINALLY have the advance curve for Chrysler.

Sure seems like advance coming in fast...my engine idle at about 750 rpms...according to the info given, I would have 15 deg advance in at idle :confused::confused::confused::confused:

My boat is an '85 with electronic ignition, but I think the curve should be the same.

How do you guy decipher this info????
 
Remember distributor rpms are half of crankshaft rpms. The info says distributor rpms...

The curve is

Crankshaft rpms

5* base timing

900/2* (7*)total advance
1200/7* (12*)
1400/10*(15*)
3200/13*(18*)
4400/15*(20*)

Doesn't make sense to me... help me out someone :mad:

Looking for advance curve '85 318s electronic ignition....THE BIG MISTERY...]:confused:
 
Tundrarules, the first red flag for me with the Pertronix information, is the distributor shown in the illustration.
Take a look for yourself.
http://www.pertronix.com/support/manuals/pdf/billet.pdf

If this was truly Marine information, they would not be showing an automotive ignition distributor!
I think that they would be illustrating a Marine Ignition Distributor.

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

I don't know if I mentioned this in this thread, but the High Performance auto engine passes through the most critical RPM range (the range where detonation may be a greater risk) rather quickly. Whereas our Marine engines may sustain this RPM for a longer duration.
Wrong curve, wrong TA at the wrong RPM, and Bingo....... possible detonation!


I could easily make some SBC suggestions for you, but I'm not confident that the 318/360 requires the same curve and/or TA.

I do know that:
No marine engine is going to like anything more than BASE or Initial advance at idle.
No marine engine requires any mechanical advance (or EST influence) prior to 1k RPM.
There's simply no need for it.




In the info shown below:

The numbers here are goofy to me.
It's easy enough to convert the distributor RPM into Crank RPM..... that's not the issue.
The issue is when you plot this out in graph form.

Let me explain that:
Note the key words "Distributor Degrees at Distributor RPM".
Distributor turns one half crankshaft RPM... or 2 crankshaft revolutions per 1 distributor revolution.
1 distributor degree = 2 crankshaft degrees.... or 2 crankshaft degrees is 1 distributor degree.

In my world, ignition timing has always been done at Crankshaft angle.... not distributor angle.

If we take that information literally, here's what you have.
Chrysler specs in Blue text.
Actual crankshaft data = 2 x's distributor degrees and distributor RPM in Brown text.

First set of numbers:

0* @ 275 to 425 = 0* crankshaft angle @ 550 to 850 crankshaft RPM....... If this is minus BASE advance, this is reasonable.
0* to 7.5* @ 425 = 0* to 15* crankshaft angle @ 850 crankshaft RPM........ Add BASE of 5*, you have a potential of 20* @ 850 RPM. This is not reasonable.
6* to 8* @ 550 = 12* to 16* crankshaft angle @ 1,100 crankshaft RPM....... Add BASE of 5*, and again, this in not even close.

12* to 16* @ 1,100 RPM and we have not yet added BASE..... ??? :eek:


Let's look at the second set of numbers:

0* to 2.5* @ 450 = 0* to 5* crankshaft angle @ 550 to 850 crankshaft RPM..... If this is minus BASE advance, this is over the recommended 5* BASE.

5* to 7* @ 600 = 10* to 14* crankshaft angle @ 1,200 crankshaft RPM...... This is a huge jump in just 200 to 400 RPM and we haven't even considered BASE.
8* to 10* @ 700 = 16* to 20* crankshaft angle @ 1,400 crankshaft RPM...... That's a 2* to 4* jump in just 200 RPM and again, we haven't even considered BASE.

11* to 13* @ 1600 = 22* to 26* crankshaft angle @ 3,200 crankshaft RPM....... Add a BASE of 5*, and this becomes 31*.
31* may be realistic for the a Good Quench Built SBC.... just not sure about the Chrysler 318/360.

13* to 15* @ 2200
= 26* to 30* crankshaft angle @ 4,400 crankshaft RPM........ Again, add a BASE of 5*, and this becomes 35* @ 4.4k RPM.
At 4.4k RPM, we're likely over the OEM WOT RPM.
At even near 4.4k RPM, we should be well up on plane where engine loads should be reduced some.
However, seldom do we see progressive Marine Cruiser engine curves ranging up to 4.4K RPM.

attachment.php






My limited Chrysler Marine experience conclusion:
In spite of this info, we still have a mystery on our hands! :mad:


.
 
Last edited:
Remember distributor rpms are half of crankshaft rpms. The info says distributor rpms...

Crankshaft rpms

5* base timing

900/2* (7*)total advance
1200/7* (12*)
1400/10*(15*)
3200/13*(18*)
4400/15*(20*)

Looking for advance curve '85 318s electronic ignition....THE BIG MISTERY...]:confused:

NOTE: "Distributor Degrees at Distributor RPM".

In your numbers above, you must also double the distributor degrees to acheive crankshaft angle in degrees.
Look at your numbers and compare to how I did the conversion.


Just an FYI: whether mechanical points w/ mechanical advance, electronic triggering w/ mechanical advance, or an EST ignition, the advance curve will be very similar for Marine use.

.
 
Last edited:
I'm failing to see how the mystery is yet solved.

Have you purchased or downloaded the service manual?
If so, would you be so kind as to post the Marine Ignition timing specs for the 318/360?
Not the automotive, and not just the BASE advance specs, but the Marine Engine progressive advance and the TA and TA RPM!
Those are what we need to see!

Much thanks if you do!

.
 
I do not have the service manuals. Someone sent that info to me via email pdf.

If someone has a 80s Chrysler Marine Engine manual, please look up this info for all of us. :D
 
I have an idea, but there's a caveat here.

ME.com sells these manuals, and would like it if we purchased from them..... sounds only fair......, agreed?

You 318/360 Chrysler guys would no doubt buy the manual if this Ignition Curve/Limit information was included in the manual.... correct?

What say I email Andrew, link him to this thread, and ask him to pull a manual from inventory.
Ask that he take a quick look to see if more than just BASE advance is listed for the 318/360 Marine Engine.
I mean a real curve that is different from these silly numbers that we've been seeing thus far!

Fair nuff?

If included in the manual.........., there ya go! :D


Edit:
I just fired an email to Andrew.
His ears are probably burning this very minute. :D


.
 
Last edited:
I just looked at the PDF file and found the 440 info.
It looks like a repeat of what we've already discussed.

440 Marine:


0 @ 275 to 425 = 0* @ 550 to 850 rpm at the crankshaft. This makes sense because it would be BASE only.


0 - 7.5 @ 425 = 0 to 15* @ 850 rpm at the crankshaft. Add BASE, and it makes no sense at all.


6 - 8 @ 550 = 12* to 16* @ 1,100 rpm at the crankshaft. Again, add BASE, and it makes no sense at all.


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

Kim, here's my take from my limited knowledge and years of having been away from using a Distributor Machine, of which is where we really get to see how these springs affect advance!

BASE advance is a result of the distributor housing position or indexing since no mechanical advance is seen during BASE mode.
So try to think of this as though the flyweights are being held closed during BASE mode.
We simply adjust the distributor housing to achieve BASE advance.
IOW, we could hypothetically achieve BASE advance with a completely frozen distributor advance mechanism.

On that note, rusty or weak flyweight springs are often why we'll see an engine surge or hunt for an RPM while at idle.
We want zero mechanical advance until approximately 1k rpm.


Each flyweight is capable of advancing the timing.
The light weight spring allows one flyweight to give the first linear line of progressive advance.
The heavier weight spring (effective at a higher RPM) allows the other flyweight to give the second stage of a linear line of progressive advance.

Either of these lines are above/beyond BASE advance.


5* @ 900 rpm would be considered BASE (no mechanical yet).
15* @ 1,400 rpm would be too much/too early, IMO.
20* @ 4,400 rpm would be Full-In.
(A) 20* is rather low for a Full-In number, even with BASE added.
(B) this is a rather high RPM to show an advance number for Marine use, IMO.


For me, the mystery continues, so I'll be making a phone call to London.
cornell_holmes_glass.jpg


.
 
I'll gladly pay the $3 if the info is all inclusive and correct. However, I am highly doubtful.


My name is XXXXX XXXXX X will be helping you today. Most questions will involve troubleshooting, and usually take many posts back and forth. Post back with as many questions as needed.


Hi there,
I have the factory Chrylser manual on this. And I gave it a look through and they only list a specifcation for your idle ignition timing. they do not give a chart or list full advance.

I have access to all of the aftermarket Seloc manuals as well, I took a look in there for you, and again there is only a spec for base ignition idle timing.
There are no charts and no printed spec for full advance.

Will the base idle timing be sufficient for you, or you you really need some kind of chart for this (of which I don't know where you would find one, so I would opt out of the question)

Unfortunately I do not think a chart exists, and I've never seen a spec for full throttle advance timing.

I ran through my automotive database just for the heck of it. Even the trucks
from the 70's and 80's with the 318 do not give a full throttle timing spec, all they give is the base.

I will opt out just incase another expert has something I do not have. But I wouldn't hold your breath on this one. To be honest with you I just don't think the chart (or even the spec) that your looking for exists.


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

I just sent this to the Ask a Marine Mechanic

The Chrysler 318/360 advance curve in graph from, including a varying range of progressive advance numbers and corresponding rpm, apparently does not exist in the form of Chrylser Marine Corporation information.
Please, NO Seloc and NO Clymers information.
Many have posted what they have thought to be advance numbers, but these have been incorrect.

To see an example of what these men are looking for, take a look at the ignition advance curve for the Marine SBC.
You can also find a curve for the 5.0L and 5.8L Ford engines.

293953.jpg

or
http://www.marineengine.com/discus/messages/12487/293953.jpg

Rick @ RicardoMarine


.
 
I'm as skeptical as you are Rick...just stumbled across that post, saw it was current, and figured I'd share.

Now, based on lack of OEM spec's, I figured a trusted aftermarket would be the best place to start. Our good friends at Mallory, yes the Unilite builders, said their replacement distributors for the 318's are provided with 24 degrees, at 3200 rpm...and say they have had no issues using this curve. May not be Factory values but their performance kind speaks for itself...my two cents
 
I'm as skeptical as you are Rick...just stumbled across that post, saw it was current, and figured I'd share.

Now, based on lack of OEM spec's, I figured a trusted aftermarket would be the best place to start. Our good friends at Mallory, yes the Unilite builders, said their replacement distributors for the 318's are provided with 24 degrees, at 3200 rpm...and say they have had no issues using this curve. May not be Factory values but their performance kind speaks for itself...my two cents
Yes, I believe that is correct. Add BASE of 5* and that's 29* TA @ 3,200 RPM.

I had called Mallory a few weeks ago and posted what I was told (same numbers, BTW), but I can't remember which thread that was in.

If you also recall, I plotted out those silly OEM Chrysler numbers in post #32 in this thread a while back.
When plotted out, the curve really looks goofy.
http://www.marineengine.com/boat-forum/showthread.php?395819-m440x-timing/page2

Yes, I caught the Unilite comment! :D :D :D

That's fine unless you cruise at 2,500 rpms, which I do!

Jeff
If this is a planing hull, and if 2.5K rpm gets you fully up on step, that would work if the progressive advance is correct for that RPM.
However, if 2.5K rpm does not get you fully up on step, that could be a rather dangerous rpm to be cruising at, IMO.
Perhaps not only dangerous, but you're certainly waisting fuel as well.

If we're going to detonate an engine, it will be more likely to detonate at/near 2,500 rpm while pushing lots of water, than if operating at a higher rpm with less hull friction.


.
 
Last edited:
Back
Top