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Twin chrysler firing order & wrong intake manifold causing idle/start issues?

FstaRockr Burns

FstaRockr Burns

Regular Contributor
Hi all - thought Id start a new thread for this issue. Spent a few hrs today working on the starboard motor in a 68 bertram.. For the life of me I could not figure out what the heck is happening with the multiple timing marks all over the flywheel, one stripe, 4 stripes, 2 stripes! And no 0 - only on the engine plate is there a 0..

I removed plug #1 and buzzed starter till I was on the compression stroke (verified 3 times).. There were 4 marks and a trailing single mark - NO IDEA which one is the actual marker.. Anyway - I tried my best and set the timing by rotating the dizzy against the rotor till I got a good idea of where the spark wd be.

I set the timing according to the intake manifold and it would NOT run.. I tried reversing the firing order stamped on the manifold - and it took almost instantly..

Now my 2nd issue - on BOTH motors the firing order says 1-8-4-3-6-5-7-2 however that firing order does not work on the counter clockwise motor.. The flywheel (as seen from rear looking fwd) rotates clockwise and the rotor moves counter clockwise -




Here is a pic of the intake of the stbd motor (using reverse firing order seems to work much better):

DSC_6191.jpg

Could using the wrong manifold cause these issues? Stalling / hunting at idle? When I give it throttle is has a smooth sound and seems very powerful.

Here is a pic of the motor - not sure what size? At read of intake there is a big A after the Chrysler..

DSC_6190.jpg


Here are the confusing timing marks on the flywheel:

DSC_6189.jpg



Can anyone shed some light? The stbd carb went thru the ultra sonic cleaner, blew out - installed a kit.. and on the starboard motor it still struggled to idle.. hunted a little here and there (vac ports plugged).. When I put it on the port motor it ran MUCH better.. the plugs are burning a tan and for the life of me struggling to figure out what the issue is -

Im wondering if someone didnt erroneously install a regular rotation intake manifold on the counter rotation stbd engine and if it wd cause issues?
 

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FstaRockr Burns said:
Hi all - thought Id start a new thread for this issue. Spent a few hrs today working on the starboard motor in a 68 bertram.. For the life of me I could not figure out what the heck is happening with the multiple timing marks all over the flywheel, one stripe, 4 stripes, 2 stripes! And no 0 - only on the engine plate is there a 0..
Theoretically (and only if these marks are correct), the single notch (when aligned with the zero) will indicate #1 TDC.
However, keep in mind that #1 TDC comes around twice.
When setting up your spark plug cables, you will want to stop the crankshaft @ #1 TDC on the C/S only.


I removed plug #1 and buzzed starter till I was on the compression stroke (verified 3 times).. There were 4 marks and a trailing single mark - NO IDEA which one is the actual marker..
If in doubt, you will want to perform a PPS procedure.
The PPS procedure is the only method for determining true TDC on an assembled engine.


Anyway - I tried my best and set the timing by rotating the dizzy against the rotor till I got a good idea of where the spark wd be.

I set the timing according to the intake manifold and it would NOT run.. I tried reversing the firing order stamped on the manifold - and it took almost instantly..
Yes, the OEM firing order that is cast into the intake manifold would be for a Std LH Rotation Engine.


Now my 2nd issue - on BOTH motors the firing order says 1-8-4-3-6-5-7-2 however that firing order does not work on the counter clockwise motor..
Yes..... that would be correct.

NOTE: the forward-most cylinder is always #1.
For a REV RH Rotation Engine, you will still begin your firing order with #1, and then you will follow that with #2, #7, #5 etc.


The flywheel (as seen from rear looking fwd) rotates clockwise and the rotor moves counter clockwise -
All Engine Rotation is determined as though viewing the engine from the Flywheel End.
(see image below)

A Std LH Rotation Engine flywheel turns CCW, whereas a REV RH Rotation Engine flywheel turns CW.
But again..... this is as though being viewed from the flywheel..... not from the front of the engine!




Here is a pic of the intake of the stbd motor (using reverse firing order seems to work much better):
Do not forget the importance of obtaining the correct Progressive and Total Advance for the Marine Engine.

View attachment 16788

Could using the wrong manifold cause these issues? Stalling / hunting at idle? When I give it throttle is has a smooth sound and seems very powerful.
I'm not a Chrysler Marine Engine expert, but I highly doubt that there is a difference between a LH and a RH rotation engine intake manifold!


Here is a pic of the motor - not sure what size? At read of intake there is a big A after the Chrysler..

View attachment 16789


Here are the confusing timing marks on the flywheel:

View attachment 16791



Can anyone shed some light? The stbd carb went thru the ultra sonic cleaner, blew out - installed a kit.. and on the starboard motor it still struggled to idle.. hunted a little here and there (vac ports plugged).. When I put it on the port motor it ran MUCH better.. the plugs are burning a tan and for the life of me struggling to figure out what the issue is -

Im wondering if someone didnt erroneously install a regular rotation intake manifold on the counter rotation stbd engine and if it wd cause issues?
See above.
Click to expand...




As viewed from the flywheel end:
The first image shows the operating direction of a Std LH Rotation Engine.
Second image shows the operating direction of a REV RH Rotation Engine.
 

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Hi ric thanks - I know the compression stroke is where u set timing.. I do have a piston stop but have no clue what size the chrysler socket is-ill take a few large ones with me and the breaker bar, I have literally been moving the motor via the flywheel teeth exposed under the timing cover on the rear transmission case.

I think I have it about as spot on as I can.. Only other idea is perhaps the pcv valve is faulty and thre is another leak on the carb.. above idle she sounds awesome - but hunts down low.

Its my first carter build and I noticed the small rubber oring that sits between the carb body and choke - so made sure its sealed. Ill try again in about 3 hours and see.

I do have a piston stop as well - ill go and make some checks today.. Either way she does run.

Lastly - what volts "should" i get on the coil + when running? currently its around 5-6v which is very low, I was under the impression it shd be around 8-9v (after resistor)..? Maybe the resistor wire is bad and not supplying enough power due to overloaded resistance (bad wire/connection)

Anyway - Ill report back later. Just odd why they would stamp the wrong firing order on the intake (unless this is intentionally done so they wouldnt have to make more castings/save cost)
 
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FstaRockr Burns said:
Hi ric thanks -
You are welcome.

I know the compression stroke is where u set timing..
Correct!
Several degrees ahead of #1 TDC C/S is where ignition advance begins.

I do have a piston stop but have no clue what size the chrysler socket is-ill take a few large ones with me and the breaker bar, I have literally been moving the motor via the flywheel teeth exposed under the timing cover on the rear transmission case.
Use caution if using the front crankshaft bolt. These can be broken if not careful!
A strap wrench would be much safer!

I think I have it about as spot on as I can.. Only other idea is perhaps the pcv valve is faulty and thre is another leak on the carb.. above idle she sounds awesome - but hunts down low.

Its my first carter build and I noticed the small rubber oring that sits between the carb body and choke - so made sure its sealed. Ill try again in about 3 hours and see.

I do have a piston stop as well - ill go and make some checks today..
If you have not used the PPS and degree wheel before, don't hesitate to ask!

Lastly - what volts "should" i get on the coil + when running? currently its around 5-6v which is very low, I was under the impression it shd be around 8-9v (after resistor)..? Maybe the resistor wire is bad and not supplying enough power due to overloaded resistance (bad wire/connection)

Anyway - Ill report back later. Just odd why they would stamp the wrong firing order on the intake (unless this is intentionally done so they wouldn't have to make more castings/save cost)
Correct!
These engines originated in the automobile world, so there is no need for a REV firing order to be cast into the manifold.


Hang in there........ you'll get it!
Click to expand...
 
Hi- so popped in new plugs yesterday and the motor is idling smooth as can be. (fyi I had the timing spot on - starts instantly). My innova light broke after 5 months of very light use so Ill re-verify but anyway..

I appreciate the replies Ric - thanks!

Another issue I ran into was those steel filters before the carbs - Im thinking of removing them to be honest.. There already is a large filter BEFORE the pump and lines are metal (no rubber bits! apart from diaphragm failing).. I can upgrade to a 5/8 steel filter (by adding 2 couplers to the 5/16 flare nuts). Another option is to remove old lines and replace with A1 rubber hose straight from the pump output - is this a better option?
 
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FstaRockr Burns said:
Hi- so popped in new plugs yesterday and the motor is idling smooth as can be. (fyi I had the timing spot on - starts instantly).
Keep in mind that BASE is BASE. We fire up on BASE and we idle on BASE....... and that's it.

The more important aspect of ignition advance will be the "Progressive" and the "Total Advance" @ a given and pre-scribed RPM!
In other words, I would not only check/set BASE, I would look further to see what the system is doing once passed BASE!

Unfortunately, this is when we need to look at the illusive and non-existent Chrysler Marine OEM ignition advance curve!
Without this curve graph, we toss the dice.... so to speak!



I appreciate the replies Ric - thanks!

Another issue I ran into was those steel filters before the carbs - Im thinking of removing them to be honest.. There already is a large filter BEFORE the pump and lines are metal (no rubber bits! apart from diaphragm failing).. I can upgrade to a 5/8 steel filter (by adding 2 couplers to the 5/16 flare nuts).
The marine cartridge style primary filter is more than adequate.
Your carburetors should be fitted with inlet filters that would capture any fuel pump related debris.
In my opinion, the small automotive in-line filter media is way too small.
Plus, (even through the pressure is only 4 to 7 psi) these should not interrupt the pressure side of the fuel line.

Another option is to remove old lines and replace with A1 rubber hose straight from the pump output - is this a better option?
With the correct length/size barbed fittings and with the correct band clamps (Euro style) the A1-15 fuel line is approved!
Click to expand...




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Sounds good. I have all the parts to make up fuel lines. Ill re check to see if the inlet fittings had the carb filters in or not.. I think Rochester ones fit inside carter carbs - so ill order 2 plus springs if I need to..
 
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So glad to hear your up and running smooth!!!!

Its like living it all over again!! Took me a day to figure out the intake marks are standard rotation only, no such thing as a counter rotation intake.. both dist run in same direction. Only mechanical difference is crank (oil grooves on journal), cam gear/lobes, and starter

Your timing assumptions are right on 5*, 10*, 15* you see why I recommended the yellow marks.

have you run them up and tried to start hot yet?

those look like FWC big blocks is that right, do you have a casting number from block?

Please make sure your running 20-50VR-1 and add zinc, you will absolutely ruin your flat tappet cam and lifters if not. I learned the hard way.

you can have a backup Mopar box from NAPA for $30 and use epoxy filled coils because they get super hot on the intake like that.

have those dist matched and rebuilt it will make a huge difference.
 
have those dist matched and rebuilt it will make a huge difference.
Click to expand...


I fully agree. This can be done to most any old school mechanically advancing ignition system. New shaft bushings, adjusted flyweight system and flyweight return springs, and so on.

However, there is an issue that we may not have considered.

At the risk of being redundant, and as I said earlier, no one to date has been able to find a Chrysler Marine Corp ignition advance curve graph for any Chrysler Gasoline Marine engine.
We can find what Chrysler suggests for BASE advance..... but we find ZERO showing the Progressive and TA.
Without this curve graph, a shop who owns and operates an Old School Sun, Allen or King ignition distributor machine will not have the info needed to bring the curve back to within Marine Engine specs.

Secondly, most of the shops who are equipped with a distributor machine are automotive shops.
Automotive techs and Automotive enthusiasts tend to know much more about the automotive ignition advance curves than that of the Marine Engine advance curves.
The Auto curve may be more aggressive.
The Auto TA may also be higher!
These engines do not undergo the same extreme and constant loads, and if we put these specs into a Marine Engine scenario, we may have trouble!!!!!!

Also, if using BASE advance numbers alone, keep in mind that any change to BASE is an Equal change to the Progressive and TA.
Example:
If we adjust BASE to 5* BTDC, our TA will be XX* BTDC.
If we change the BASE from 5* to 10*, our TA will now be XX + 5* BTDC.
A 5* shift in TA can make the difference between NO Detonation and Detonation.
This would be Ignition Induced Marine Load Detonation, and can be very destructive.

Point being..... I would strongly suggest that we DO NOT haphazardly set up ignition advance without the aid of a proper curve graph for a particular Marine Engine!

Somewhere out there, there has to be something that was provided by Chrysler Marine........ we just simply can't find it!


If a Chrysler Marine Corp engine ignition curve graph is to be found, it will look similar to this GM curve.

 

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RicardoMarine said:
I fully agree. This can be done to most any old school mechanically advancing ignition system. New shaft bushings, adjusted flyweight system and flyweight return springs, and so on.

However, there is an issue that we may not have considered.

At the risk of being redundant, and as I said earlier, no one to date has been able to find a Chrysler Marine Corp ignition advance curve graph for any Chrysler Gasoline Marine engine.
We can find what Chrysler suggests for BASE advance..... but we find ZERO showing the Progressive and TA.
Without this curve graph, a shop who owns and operates an Old School Sun, Allen or King ignition distributor machine will not have the info needed to bring the curve back to within Marine Engine specs.



Secondly, most of the shops who are equipped with a distributor machine are automotive shops.
Automotive techs and Automotive enthusiasts tend to know much more about the automotive ignition advance curves than that of the Marine Engine advance curves.
The Auto curve may be more aggressive.
The Auto TA may also be higher!
These engines do not undergo the same extreme and constant loads, and if we put these specs into a Marine Engine scenario, we may have trouble!!!!!!


Also, if using BASE advance numbers alone, keep in mind that any change to BASE is an Equal change to the Progressive and TA.
Example:
If we adjust BASE to 5* BTDC, our TA will be XX* BTDC.
If we change the BASE from 5* to 10*, our TA will now be XX + 5* BTDC.
A 5* shift in TA can make the difference between NO Detonation and Detonation.
This would be Ignition Induced Marine Load Detonation, and can be very destructive.

Point being..... I would strongly suggest that we DO NOT haphazardly set up ignition advance without the aid of a proper curve graph for a particular Marine Engine!

Somewhere out there, there has to be something that was provided by Chrysler Marine........ we just simply can't find it!

UNDERSTOOD! SO LETS GET TOGETHER AND FIGURE THIS THING OUT. IVE BEEN READING FOR 5 YEARS ABOUT YOU JUMPING UP AND DOWN ABOUT CHRYSLER MARINE TIMING. IT MUST BE OUT THERE SOMEWHERE?!!?

RIGHT NOW YOU MUST USE AN OPERATIONAL OEM DISTRIBUTOR FROM A MOTOR AND FIND THE TOTAL ADAVNCE(MECHANICALLY LIMITED EASILY FOUND WITH THE RIGHT EQUIPMENT) THEN MAKE YOU BEST EFFORT TO MATCH THE REQUIRED TA RPM. ALL THIS HAVING BEEN SAID YOUR WAY BETTER OFF REBUILDING WITH SOMEONE THAT KNOWS MARINE CURVES AND HAS A DUAL DIST MACHINE THAN LEAVING A 40 YEAR OLD BROKEN SPRING RUSTED OUT POS WHICH MOST HAVE IN THE HOLE OF A MOTOR THAT LOOKS LIKE THESE ONES DO...


If a Chrysler Marine Corp engine ignition curve graph is to be found, it will look similar to this GM curve.

TWO THINGS STRIKE ME AS ODD IN THIS CURVE
1 THE TOTAL ADVANCE IS ONLY 25*
2 ITS NOT ALL IN UNTIL 3700 RPM!!?

-tony
Click to expand...
.........
 
In answer to the OEM curve dillema here is one I found. So quit saying they aren't around. Just have to look. Pretty useless, no wonder they are non-existent or lost. I have an unused 4142738 and a good used 3675974 that are similar internally that I can use. I may run them on a machine to establish my base.
 

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Tony - it seems the graph is in fact all in by 3500/3700.. Also - when using old 60s 70s timing, drop a few degrees off to be on the safe side, newer fuels take a little longer to burn anyway so even sticking at stock base will put u in a safe margin. #2 - 25 max is a safe enough margin for anyone, most marine engines have a cool suppl of water unlike a radiator - further decreasing the chances of pre-ignition imo-

The fact that curves arent available doesnt seem too much of an issue really, a v8 will run like most v8's - 28 degrees max and base of 5-8 and you will be doing causal boating for decades.
 
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603dad said:

Rick said:
Somewhere out there, there has to be something that was provided by Chrysler Marine........ we just simply can't find it!
Click to expand...

UNDERSTOOD! SO LETS GET TOGETHER AND FIGURE THIS THING OUT.
Be my guest!
When /if you do find an OEM Chrysler Marine Corp ignition advance curve for the OP's engine, please let us know!

IVE BEEN READING FOR 5 YEARS ABOUT YOU JUMPING UP AND DOWN ABOUT CHRYSLER MARINE TIMING. IT MUST BE OUT THERE SOMEWHERE?!!?
I do not recall jumping up and down regarding this.
However, due to the importance of this, I have posted to this effect more than several times.

RIGHT NOW YOU MUST USE AN OPERATIONAL OEM DISTRIBUTOR FROM A MOTOR AND FIND THE TOTAL ADAVNCE (MECHANICALLY LIMITED EASILY FOUND WITH THE RIGHT EQUIPMENT) THEN MAKE YOU BEST EFFORT TO MATCH THE REQUIRED TA RPM.
No disagreement there.
With a Sun, Allen or King machine, the operator would be able to see the existing curve, and would be able to plot it out.
However, if the existing curve is incorrect (due to old age and advancing system wear), that would render the info rather useless...... yes/no?

ALL THIS HAVING BEEN SAID YOUR WAY BETTER OFF REBUILDING WITH SOMEONE THAT KNOWS MARINE CURVES
Again, no disagreement...... but where is the OEM curve that this person would be using?????

AND HAS A DUAL DIST MACHINE
I guess that I'm not familiar with a Dual Dist Machine.
Would you please explain?



Rick said:


If a Chrysler Marine Corp engine ignition curve graph is to be found, it will look similar to this GM curve.
Click to expand...

TWO THINGS STRIKE ME AS ODD IN THIS CURVE

1 THE TOTAL ADVANCE IS ONLY 25*
Look more closely at the verbiage to the left side of the vertical scale.......
Most all curve graphs are minus BASE advance. When BASE is added, you will see the correct TA.

2 ITS NOT ALL IN UNTIL 3700 RPM!!?
Look more closely at my comment just above the image that I posted.
This is an example ONLY of a Marine Engine ignition advance curve....... it is NOT a curve for the OP's Chrysler Marine engine !!!!!!!
[FONT=Tahoma, Calibri, Verdana, Geneva, sans-serif][/FONT]
.........
Click to expand...
 
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FstaRockr Burns said:
Tony - it seems the graph is in fact all in by 3500/3700..
I must ask..... What graph?
The curve graph that I posted was to be an example ONLY as to show us what we would be looking for in a Chrysler Marine ignition curve graph!


Also - when using old 60s 70s timing, drop a few degrees off to be on the safe side, newer fuels take a little longer to burn anyway so even sticking at stock base will put u in a safe margin. #2 - 25 max is a safe enough margin for anyone, most marine engines have a cool suppl of water unlike a radiator
Remember, a lazy ignition advance makes for a lazy LPCP.
A lazy LPCP makes for less torque.

- further decreasing the chances of pre-ignition imo-
Our concern would be Detonation..... not Pre-ignition!

The fact that curves arent available doesnt seem too much of an issue really,
Then again, I must ask....... how does a Chrysler Marine engine owner maximize his engine's performance?

a v8 will run like most v8's - 28 degrees max and base of 5-8 and you will be doing causal boating for decades.
You must associate a Total Advance with an RPM. Otherwise, TA numbers are meaningless!
Click to expand...

Here is another example ONLY of a Marine Engine ignition advance curve.
NOTE: this is an example ONLY.... repeat..... this is an example ONLY.
It is not a correct ignition advance curve for the Chrysler Marine engine.
I am posting this image as to show us an example ONLY of what we would hope to find IF Chrysler Marine has made such a graph available.

NOTE: the line graph advance degree values are minus the BASE or Initial advance value.
NOTE: when strobing the timing marks dynamically, the BASE/Initial degree value can't help but to be included in what we see.
 

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Ok..... it looks as though we are getting somewhat away from the original topic ...... but since we're here, let's further the importance of a correct ignition advance for a given gasoline powered internal combustion engine!

Engineers have spent countless hours testing to determine what ignition lead works best for a given engine and at a given engine RPM.
Each combustion chamber design, piston profile, camshaft design etc, are all rather unique. This means that not all ignition curves will work across the board for all engines. This can easily be seen if we were to compare the Ford, GM, Volvo Penta ignition advance curves from one engine to another.

Let's also understand that Pre-Ignition and Detonation are not the same phenomena.


We also need to understand what LPCP is.
LPCP = location of peak cylinder pressure.
According to most engineers, LPCP is most effective when it occurs at/near 12 to 14 degrees ATDC (crankshaft angle After Top Dead Center).
This is true for any piston style lawn mower engine, aircraft engine, motorcycle engine, boat engine, etc.

Baring that all else is correct, the ignition lead is given the last word in the placement of LPCP.
(variables would be fuel quality)


Sounds easy to accomplish this..... right?
Not so due to other contributing factors! Quench -vs- no quench, poor combustion chamber design and so on!


An ignition lead for one engine that gives us a great LPCP may not work so well in another engine. This is why each engine manufacturer has established their own OEM ignition advance curve. Chrysler Marine engineers certainly established a curve, but it would appear that they neglected to make it available to the end user.

So, in an effect to further this, let's use the correctly built SBC Marine Engine for an example.
This SBC will use a Q/E style piston..... not the GM full dished piston that we all too often see! :mad:

The BASE or Initial ignition advance will be in the range of 8* to 10* BTDC.
The Progressive advance will be somewhat linear.
The TA (total advance) will be at/near 30-32* BTDC @ 3,200 rpm (Q/E SBC only..... the GM version will be less).
The RPM at which this occurs is extremely important!
Too soon, and it may cause the cylinders to undergo Detonation.
Too late, and the LPCP becomes lazy, leaving the much needed torque on the table!

Again, baring that all else is correct, the ignition advance @ 3,200 (example only) rpm will place the LPCP at/near the desired 12* to 14* ATDC, all while avoiding Detonation.

Ford, GM, PCM, Marine Power, Volvo Penta, etc, all offer an ignition advance curve for each engine so that the technicians are able to verify that the ignition system is doing what it's suppose to be doing.


This leads me to the question...... "Where is Chrysler Marine's OEM ignition advance curve?????" Not just BASE alone......... we're talking about the Progressive Advance and the Total Advance @ an OEM prescribed RPM!

I would love to see one, as I'm sure that you would!


Edit:
If the above makes sense to you, you should now be able to understand why I have a concern for the Chrysler guys!




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