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Q engine ignition issues.

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CarlJ

New member
Hi everyone!
New poster here long time follower though. I have a 1973 30' CC Express bridge with twin 307Q's that have been re-powered to 350 ci long blocks (retaining all 307Q accessories). I have been having a re-occuring stalling issue with the port engine where after 10 minute warm up or extended running it will stall and not re-fire for several minutes. I've replaced the cap, rotor, points and condenser (Mallory flat cap, single point) and coil (external resistor). My fear is that I may be doing harm to the coil because I'm on the second one in two weeks now. Iv'e seen posts regarding the external resistor and assume that if it's bad, that could be causing the coil to overheat? And eventually go bad? Also is it an actual resistor or a wire with built in resistance.

Thanks
Carl
 
Take a voltage reading at each side of the ballast resistor.
Make sure that the ignition coil requires the ballast resistor.

You may find this to be a good read.
It pertains to automotive, however, short of advance curves, much can be used to help with our conventional Marine systems.



This testing procedure is valid for most automotive coils (this should include our conventional marine systems):

Using an ohmmeter, check the resistance between the side terminals of the coil.
Do this with all of the wires to the coil disconnected.
You should see 0.75 to 0.81 ohm of resistance.
Then check the resistance between either side terminal and the center high tension terminal. The reading should be 10,000 to 11,000 ohms.
Any significant deviation from these numbers would indicate that the coil is defective.



Side note:
Your 1973 standard points type distributors are nearing 39 years old.
39 years of use may have caused worn shaft bushings, worn advancing system flyweights, worn flyweight return springs, etc, etc.
This can all add up to incorrect igntion triggering, and/or progressive ignition advance.
Worn shaft bushings can cause the dwell to fluxuate, and at all/any RPM.

Perhaps it's time for an ignition system upgrade.
Not the Pertronix kits :mad: :mad: :mad: .... we're talking about a real upgrade that involves a complete replacement!

Food for thought! ;)


.
 
Rick,
Thanks for the awesome information. The quick refresher course was needed. I agree that the distributor could be worn to the point of replacement and it is something that I want to do. Now I must reiterate my concerns. The coil is one that requires a resistor. Thats a fact. Both engines have coils on them that say "with external resisitor". Once again, would that resistor being bad cause a coil to go bad? Also I can't find a resistor mounted anywhere. Could it be a wire that has the resistance built in? My CC engine manual has a schemetic but there aren't any resistors called out on it or listed in the parts list. One last thing. Other than being defective, what could cause my dwell/tach/voltmeter to give me an rpm reading off the scale at idle, and low voltage readings?

Thanks
Carl
 
Carl, if a resistor wire is being used in lieu of a ballast resisitor, it should show up when doing a voltage reading on the ignition circuit.
 
RicardoMarine said:
Carl, if a resistor wire is being used in lieu of a ballast resisitor, it should show up when doing a voltage reading on the ignition circuit.
Click to expand...
Had similar problem with a 350 Q and L engine in a Catalina we purchased last year. Went through 2 coils resister type. Points would pit A short time into the season and would have to be replaced. Changed to Mallory electronic ignition for both distributors 5 weeks ago. So far the engines hve never run so well. Start right up and run strong. I believe the wrong coils were on the engines to start with, the manual was not clear on what type of coil the engines should have, nor was there any resister wire or ballast resister found. I had to replace the coils when installing the new electronic system including new coil wires, but like I said she runs great now.
 
Tim,
If you could please point me in the direction as far as part numbers and such of the ignition system that you installed. Sounds like the way to go.

Thanks
Carl
 
Hi Carl
heading to the boat shortly. Do you have the Mallory flat top distributors? I went with the Mallory electronic ignition because they updated for their own units. I will get the part numbers for you. I also called Mallory prior to ordering with the engine info and they told me what I needed for the conversion.
 
Timvail said:
Hi Carl
heading to the boat shortly. Do you have the Mallory flat top distributors? I went with the Mallory electronic ignition because they updated for their own units. I will get the part numbers for you. I also called Mallory prior to ordering with the engine info and they told me what I needed for the conversion.
Click to expand...
Sorry Carl, yes you do have the flat top caps. Will get back with part numbers shortly.
 
Ok Carl, here are the numbers. E-Spark Breakerless Conversion Kit for Mallory point Distributors.
Part Number 61005m for 8 cylinder point distributors that use a flat cap part number 221 or 221B
the kit must be used with a ballast resister or loom resistance wire to prevent damage to the module.
On my application I did not have any of the above so I used the Mallory coils part number 29219 or 29450 or 30450 which are internally ballasted. I crossed referenced the numbers at napa and saved some money on the coils.
finally, the lead from the coil to the cap needs to be carbon and not a solid steal cor such as copper, very important.
instalation for the first engine was about an hour. Second engine was about a half hour including a call to the help desk to confirm a couple of things. Overall very easy to follow instructions with help number available. And the best part is everything seems to be good after 5 weeks of running strong. Good luck.
 
I'd suggest steering clear of the Hall Effect conversions if/when possible.

Here's the Mallory MAL9-26311 with the crab style cap (not same as the old YL crab cap distributor).
This was formerly the YLM566AV for the Chevy 327Q, 350Q LH V-8 ChrisCraft application.
The YLM is a VR unit (magnetic triggering). Good stuff, IMO.

MAL9-26311.jpg
 
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Hi Rick. Yes I had a look at the other two main players who provide the conversion using the magnetic effect. The optical system(infrared) that Mallory provides for their own distributor was a perfect fit in their distributor. I know this technology is fairly new compared to the magnetic system, but the reviews appear to support the quality and overall sustainability of this product. The only maintenance is to wipe the optical eye if it gets dirty. I'am told this may happen in year round salt water use, if at all. I'am lucky if we get 5 months of use before we hall out for the winter.
we wll see how it stands up, but for now my boat has never started or run as well as it does now, including 10 percent savings in fuel. As in most updates in the marine environment, time and use will tell the tale.
regards
tim
 
Tim, I know of two means of magnetic triggering that we'll find being used in the Marine Ignition Distributors.
One would be VR (variable reluctor), and another would be Hall Effect, such as what Pertronix uses.
I won't use Pertronix version of Hall Effect, although Hall Effect intrinsically is a great means of triggering.
I just don't care for the cheezy way in which Pertronix fabricates their magnetic wheel.

Mallory's YLU is photo-eye, using the optical beam and beam breaker for triggering..... and these are very accurate!
However, the photo-eye units can fail, and when/if they do, you're DITW.
I steer clear of photo eye when possible..... but that's just my take.

The Mallory YLM is VR (variable reluctor) using the magnetic reluctor and sensor.
This has been tried and proven since the early 70's by Chrysler motors.
Mallory has been using VR for years.
I'd have to say that the VR failure rate is minimal.

Either will work.

.
 
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Hi Rick. I agree, in my early days we used a variety of electronic ignitions on the market to convert old systems on trucks to electronic, and yes some would fail for a variety of reasons. The Mallory optical beam system seems like a good choice for my application. And yes if it happens to fail while out on the water, well, that's why I have a spare kit sitting in the spare parts box on board, I like redundancy.
tim
 
Hey guys thanks for all the support and advice. Unfortunately I have first hand experience with the Mallory Unilite ignitions. I had one on my 1967 Camaro drag car and was well aware of the tiniest electrical no no that could blow that eye...and it did. And at just over $100 for that module it was prudent to buy the insurance that Super Shops offered for it. Any way, until I can get around to the ignition upgrade I have to live with what I have. My big concern still is keeping that coil alive which means digging around the engine until I find that resistor. One final question that I have is why doesn't my firing order match the manual? and to help sort that out which cylinder is number 1? On my chevrolet cars number 1 was always drivers side front which on my boat would be aft starboard side (flywheel forward). Any thoughts? Thanks
 
Timvail said:
Firing order doesn't reflect the manual you have?????????
Click to expand...
To my knowledge, all Standard LH rotation SBC's use the same firing order.


Std LH rotation engine;

sbc-firing-order.jpg



The Reverse RH rotation SBC firing order begins with #1, but is reverse of the Std LH firing order.
Reverse RH rotation engine;

1 2 7 5 6 3 4 8


The oil pump and distributor, for both LH and RH engines, rotates CW.
 
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Well I've figured out the firing order vs. chris craft manual debacle. The plug wires were on wrong. now that they have been rerouted correctly she runs like a top. Problem now as originally stated is after prolonged running the engine won't re-fire. a mechanic suggested that the voltage regulator was bad. I have the Mallory distributor so there isn't a resistor. do you guys concur?
 
CarlJ said:
I have the Mallory distributor so there isn't a resistor. do you guys concur?
Click to expand...
Which Mallory?
The YLU and YLM triggering unit will work with either resisted or non-resisted voltage.
See the Mallory instructions.

The ignition coil will determine whether or not external resistance is required.


.
 
well let me just say that the coil says external resistor on it but there isn't anything mounted on the plate on the side of the engine except the voltage regulator. The resistor must be in the voltage regulator.
 
Correct. The 12 volt coils usually say "No external resistor required" where as the ones that run with a ballast resistor (at around 9 volts) say "External resistor required".

Jeff
 
CarlJ said:
.............. and to help sort that out which cylinder is number 1? On my chevrolet cars number 1 was always drivers side front which on my boat would be aft starboard side (flywheel forward). Any thoughts? Thanks
Click to expand...
The "Front" of an engine is always the end oposite from the flywheel end.... or typically where we'll see the harmonic balancer, pulleys, timing chain, etc........ regardless of flywheel forward or V-drive installations.

The #1 cylinder is always the Forward-Most cylinder in relationship to the front/rear of the engine.... not the engine installation orientation.

And while on topic, Engine Rotation is always determined as though viewing the flywheel end of the engine.
Standard LH rotation will turn CCW when viewing from the flywheel end (or CW when viewed from the front).
Reverse RH rotation will turn CW when viewing from the flywheel end (or CCW when viewed from the front).


CarlJ said:
well let me just say that the coil says external resistor on it but there isn't anything mounted on the plate on the side of the engine except the voltage regulator. The resistor must be in the voltage regulator.
Click to expand...
Some engine harnesses will use a resistor wire in lieu of an external resistor.
Take a voltage reading on the ignition coil power lead.




.
 
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Quick update! The plug wires were on wrong. That's what I get for trusting someone else's work. Now that this is corrected I'm on to the next issue. Thank you to everyone who posted and or replied on here. I'll post back soon with updates.
 
CarlJ said:
Quick update! The plug wires were on wrong. That's what I get for trusting someone else's work. Now that this is corrected I'm on to the next issue. Thank you to everyone who posted and or replied on here. I'll post back soon with updates.
Click to expand...


Hi Carl,

I know it's been a number of years since you posted on marineengine.com about an apparent ignition problem on a 350Q rebuild.

I have a 23 lancer that we just repowered with a new engine and bolted all the chris craft parts on it to "350Q" it, including the intake manifold (new Sierra 350Q distributor)

I'm having the same experience you had where it will run for 10 or 15 minutes before misfiring and eventually stalling. Seems ignition and temperature related.

Was wondering if you ever nailed down what the problem was? I didn't see a continuation in the thread
 
While there are not rules against this.... you have posted to a thread that was started in August of 2012..... roughly 8 years ago.
Typically, if the OP has not posted since then, it's unlikely that he will now.
You will have better luck if you were to start a new thread.
 
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