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Timing a 318

Jfreeman1412

Regular Contributor
Hey guys thought I would start a new thread to tackle how to time this 1973 318. I found the rubber flap on the bell housing and seen the flywheel. However is there suppose to be stationary marks in there?

I also heard someone say something about the Harmonic Balancer. Where is that located?

Here is a picture of the front of the motor to show that i have no stationary numbers up there.

IMG0031-M.jpg
 
The pulley at the bottom of the image is your harmonic balancer. On some engines there is a timing tab above the balancer on the right. Your engine doesn't have one. Mine don't either.

You have to use the marks on the bellhousing. If you remove the rubber cover you should see an arrow or some pointer mark on the bellhousing. Use a flashlight to look for it. It can be dirty, rusty, and faded. Use some whiteout or a white paint marker to brighten it up.

There should also be a painted mark on the flywheel. It's either a dot or a triangle or a line. When you line up the flywheel mark and the bellhousing mark you're at Top Dead Center.

-JJ
 
I believe that some I/B's did use the flywheel for ignition timing. The Chrysler guys can bring you up to speed on that.

The problem is, no where can anyone find anything but BASE or Initial advance numbers for these Chrysler Marine engines.
We've pretty much beaten that horse to death here.
We can easily find OEM numbers for the Chevrolets and Fords.

Setting BASE or Initial is one thing, but your more important numbers will be the progressive advance and the TA RPM.
I'm hopeful that someday, someone will find and post this Chrylser Marine info.

.
 
I believe that some I/B's did use the flywheel for ignition timing. The Chrysler guys can bring you up to speed on that.

The problem is, no where can anyone find anything but BASE or Initial advance numbers for these Chrysler Marine engines.
We've pretty much beaten that horse to death here.
We can easily find OEM numbers for the Chevrolets and Fords.

Setting BASE or Initial is one thing, but your more important numbers will be the progressive advance and the TA RPM.
I'm hopeful that someday, someone will find and post this Chrylser Marine info.

.

What more than this would you need? Factory Chrysler manual:
 

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Great so will there be stationary numbers/degrees on the bell housing or flywheel in which I will know how far advanced it is when i get the RPM's up? OR how will I know what degrees It is firing without any stationary numbers?
 
What more than this would you need? Factory Chrysler manual:
Excellent, Mr. Tahoerover! :)
You are the man of the hour, the week, the month and perhaps the year......, and I am experiencing a rather healthy dose of shock and awe!

Where did you find this, and what engine are these specs for? (the top hase been cut off!)
Are these for the 318 and 360 engines?????



The numbers that will be more useful for setting timing, will be these.
 

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Excellent, Mr. Tahoerover! :)
You are the man of the hour, the week, the month and perhaps the year......, and I am experiencing a rather healthy dose of shock and awe!

Where did you find this, and what engine are these specs for? (the top hase been cut off!)
Are these for the 318 and 360 engines?????



The numbers that will be more useful for setting timing, will be these.

I have never owned a small block, I have manuals for crown , ace, hemi, and RB Big blocks. I no longer have a hemi, but still have the manual.
 
Excellent, Mr. Tahoerover! :)
You are the man of the hour, the week, the month and perhaps the year......, and I am experiencing a rather healthy dose of shock and awe!

Where did you find this, and what engine are these specs for? (the top hase been cut off!)
Are these for the 318 and 360 engines?????



The numbers that will be more useful for setting timing, will be these.

I have never owned a small block, I have factory manuals for crown , ace, hemi, and RB Big blocks. I no longer have a hemi, but still have the manual.
 
RicardoMarine said:
Where did you find this, and what engine are these specs for? (the top hase been cut off!)
Are these for the 318 and 360 engines?????
I have never owned a small block, I have factory manuals for crown , ace, hemi, and RB Big blocks. I no longer have a hemi, but still have the manual.
Jfreeman, if I'm understanding Tahoerover, those numbers are NOT for the 318, so I'd NOT use them!

Dang it .... back to square one! :mad:



.
 
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Great so will there be stationary numbers/degrees on the bell housing or flywheel in which I will know how far advanced it is when i get the RPM's up? OR how will I know what degrees It is firing without any stationary numbers?

No, the bellhousing won't have stationary numbers. It will just tell you when you're at TDC. Therefore, you need to borrow/buy a timing light that has advance adjustment capability. For example, when you set the light for 5* BTDC you'll see the markings line up like you're at TDC. The adjustable light basically delays the xenon strobe to fire depending on what degree BTCD you set it to.

You can use a light like this to measure you're timing throughout the entire rpm range.

-JJ
 
No, the bellhousing won't have stationary numbers. It will just tell you when you're at TDC. Therefore, you need to borrow/buy a timing light that has advance adjustment capability. For example, when you set the light for 5* BTDC you'll see the markings line up like you're at TDC. The adjustable light basically delays the xenon strobe to fire depending on what degree BTCD you set it to.

You can use a light like this to measure you're timing throughout the entire rpm range.

-JJ

Thanks you. That is what I needed to know.

What does 5 degrees BTC mean?
 
BTC-M.jpg

So what does this mean? in correlation to the timing procedure? Is there where you start? Sorry for the lack of knowledge on this subject and thanks for your help.
 
This is pretty much what everyone has come up with so far.
Without the progressive numbers, it's rather meaningless, IMO.
We fire up, idle on, fire up and idle on BASE.... and I can't think of what else we do on BASE advance. :rolleyes:
(that's sarcasm towards Chrysler Marine....... not any of us!)






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

Yep...... we've been down this road also.
Try to make a curve out of these numbers, and note that these are distributor degrees, not crankshaft degrees.
I did this a while back in one of the 440 threads, and the numbers do not work out.
attachment.php




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

I just scrolled through the Factory 318/360 manual that Tahoerover posted a link to.
I could not find anything pertaining to ignition advance, other than a BASE of 2 and 5 degrees.
Chrysler Marine must make a huge assumption that nothing within their mechanical advancing system will change due to rust or corrosion, nor will it require varification in the future.
How can you verify if there are no numbers to verify against?
Set BASE, and call it a day?????

There's got to be some numbers out there somewhere.... and numbers that make sesne.... not this giburish stuff!

.
 
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Why can't you make a curve?
You can make a curve from those numbers, but take a look at how it plots out!

I tried this in the "M440X timing" thread from November last year.

I'm fairly up to speed on Marine Ignition advance, and I can't make any sense of those numbers.


Edit:
It's possible that I made a mistake when I plotted this out.
If anyone wants to take another shot at it, by all means please do.


.
 
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Adjust your idle to 500-600 rpm and set your timing to 5* BDTC. That's your base timing.
When you're done, adjust your idle back to 750-850 rpm.
JJ, that's all fine and dandy, but aren't you curious to know if your XX year old advancing system is working correctly?
I sure would be!

Here's an example of rusty and compromised flyweight return springs:
(of course this is assuming that the mechanism is showing some signs of wear over the years)

Do these gain spring tension, or do they loose spring tension?
Answer.... normally they loose spring tension... not gain!
If they loose spring tension, does the advance come on late, or early?
Answer... too early!
What occurs when a Marine engine under load receieves too much spark lead too early?
Answer.... detonation potential!

Now, if the advancing system simply becomes sticky and offers limited advance, we suffer performance only.
IOW, normally there is no engine damage.

I'm not argueing with anyone per se', and I have no dog an any fight here.
I'd just like to see some real usable numbers for the Chrysler guys.
So far, I've seen none! I've seen BASE advance numbers only.

Most all other manufacturers will list a curve that shows the progressive advance, and where the TA is Full In.
They must be giving some importance to this!

.
 
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JJ, that's all fine and dandy, but aren't you curious to know if your XX year old advancing system is working correctly?
I sure would be!

Here's an example of rusty and compromised flyweight return springs:
Do these gain spring tension, or do they loose spring tension?
Answer.... normally they loose spring tension... not gain!
If they loose spring tension, does the advance come on late, or early?
Answer... too early!
What occurs when a Marine engine under load receieves too much spark lead too early?
Answer.... detonation potential!

Now, if the advancing system simply becomes sticky and offers limited advance, we suffer performance only.
IOW, normally there is no engine damage.

I'm not argueing with anyone per se', and I have no dog an any fight here....., I'd just like to see some real usable numbers for the Chrysler guys.
So far, I've seen none! I've seen BASE advance numbers only.

Most all other manufacturers will list a curve that shows the progressive advance, and where the TA is Full In.
They must be giving some importance to this!

.

Yes, I would like to know but since the data is not readily available I'm not going to sit at the dock and NOT take the boat out. All I can do is set my base and determine if I think my engine is running properly. If my advanced ignition timing was off enough to cause damage or lack of performance, I think that I am knowledgable enough to diagnose it. At that time, I will investigate further. For now, I'm setting my base and taking her for a cruise. If she performs well and there's no engine hesitation or funny noises then she's good to go.

-JJ
 
JJ, I understand, and that's what most do. You sound like you're on top of it.


For those in general, understand that ignition induced detonation is not always audible, and in particular in a marine application.
Pre-Ignition and Detonation are two entirely different phenomena.
 
Checking the advance is easy but you need a timing light with the adjustable readout feature. I check mine every year and it only takes a minute. Set the base timing as described earlier and then rev the engine to about 2500 rpm then you push the buttons on the timing light until you have lined up the timing marks at 0 then read the degrees shown on the timing light, 22-25 seems normal for the boats I have owned, if it's low the advance isn't working.

Dan
 
I am reluctant to use a digitally advancing timing light for Marine. Its just too dang important to me.
One user error, or one equipment algorithm error, and it can cause a costly mistake.

I use the degree markings on the balancer, and I view ignition timing in Real Degrees and in Real Time.
Very little risk of error this way.

But that's just me!

.
 
Checking the advance is easy but you need a timing light with the adjustable readout feature. I check mine every year and it only takes a minute. Set the base timing as described earlier and then rev the engine to about 2500 rpm then you push the buttons on the timing light until you have lined up the timing marks at 0 then read the degrees shown on the timing light, 22-25 seems normal for the boats I have owned, if it's low the advance isn't working.

Dan

Rick wants to see an advance curve with readings to the nearest tenth of a degree. He doesn't care about anything you have to say unless you can produce this curve.

-JJ
 
I am reluctant to use a digitally advancing timing light for Marine. Its just too dang important to me.
One user error, or one equipment algorithm error, and it can cause a costly mistake.

I use the degree markings on the balancer, and I view ignition timing in Real Degrees and in Real Time.
Very little risk of error this way.

But that's just me!

.

Being an engineer in the medical device field, I evaluate product risk on a daily basis. I can tell you that I'd feel more comfortable using that digital algorithm than the timing tab on your engine. How do you know the tab is aligned properly? How do you know that the monkey who owned the boat before you didn't replace it with the wrong timing tab?

In my case, my stbd motor doesn't even have a timing tab.

Comparing an adjustable timing light to a timing tab is like comparing a scientific calculator to an abacus.

-JJ
 
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