1947 Chrysler Windsor

[caddy60s]

My 47 Chrysler will not start, due to no spark.  We have gone thru  a lot of the electrical and do not see any thing out of order.

 

My question is  if the timiming chain is the problem (and this might be a stupid question)  would there be no spark?  

 

Bruce

[TerryB]

If you manually open and close the distributor points, that is, start with the points closed and then open them, making sure the key in the on position of course, you can create a spark from the coil assuming all wiring is correct.  The battery voltage needs to present at the battery terminal of the coil and the points need to be connecting that voltage to ground to start the process.  It’s the opening of the points that creates the spark from the coil.

 

To answer your question, remove the distributor cap and turn the engine over with the starter.  If the rotor does not move during this engine cranking process you have mechanical problems.  If the rotor does turn while cranking you most likely have electrical issues.

[caddy60s]

T

 

I thank you for your reply and good information.  Reading between the lines, if the rotor does not move during the engine cranking the mechanical problem then could be the timming chain or other mechanical problems?

 

Bruce

[TerryB]

3 minutes ago, caddy60s said:

T

 

I thank you for your reply and good information.  Reading between the lines, if the rotor does not move during the engine cranking the mechanical problem then could be the timming chain or other mechanical problems?

 

Bruce

Yes, mechanical problem.  I can’t say if it’s timing chain or if the engine end of the distributor is the problem as I’m not familiar with how the distributor is turned by the internal engine mechanisms.  I will do some research and see if I can determine how it works.

[TerryB]

So it looks like the distributor shaft is driven by a gear on the oil pump.  If the rotor does not change position when the engine is turning over there is a big problem that needs to be diagnosed.

[caddy60s]

 

2 minutes ago, TerryB said:

So it looks like the distributor shaft is driven by a gear on the oil pump.  If the rotor does not change position when the engine is turning over there is a big problem that needs to be diagnosed.

 

[caddy60s]

Terry,

 

Thank you again for the iformation, it is important to look at all the options that could be the link to not having any spark

 

 

Regards

 

Bruce Watson

[c49er]

When you crank the engine over long enough do you have oil pressure?

If yes the timing chain and cam drive gear are OK.

If the distributor still does not turn....

.....distributor drive tang/shaft that fits into the oil pump is damaged.

.....the correct distributor is not fully inserted down into the block hole and tightened down properly

.....The 3/8" shorter Plymouth or Dodge distributor has been installed...won't reach the oil pump drive

Maybe none of the above is even the issue.

 

[caddy60s]

Iwill have to get back to you on the oil pressure etc It may be a few days before I can  do some of the tests.

 

 

Thanks again

 

Bruce

[keithb7]

You may hear many suggestions on how to troubleshoot for no spark. Folks often jump to make suggestions, assuming the basics are all working. 
 

Best to strip things right down to basics. Remove distributor Cap. Is there a rotor in there? Leave the distributor cap off. While the battery and starter are cranking the engine over, is the rotor turning? If not, look into the placement of the distributor.

Is the distributor assembly snug and in place? Bolted down to the block with the timing lock down bolt? Yes, but rotor still not turning? Likely distributor needs to come out of block for further investigation. 
 

If the rotor is turning when engine is cranking over, remove the rotor. Now you can easily view the points. Are the points opening and closing while the engine is cranking over?

 

If you are working alone, you may want to loosen/remove all spark plugs. No compression will be generated. You can then easily turn the engine over by hand. By simply turning the fan at the front. Fan is bolted to the water pump.  Lean over the fender. Driver side. Then you can watch the rotor and points moving (or not) while you turn the engine over by hand. 
 

If movement of points and rotor is confirmed and appears good, next steps likely involve a digital multimeter. To check for voltage and ground continuity at various connections. 

[c49er]

I would bet your distributor most likely does rotate when cranking the engine over..I've never seen a MoPar flathead not rotate...

[TerryB]

Bruce, post your findings and questions here, we are always glad to give help.

 Remember those contact points in the distributor are a key component in the process. Corrosion on their contact surfaces is a very common source of no spark issues.  

[caddy60s]

At this stage I have gone thru most of the suggestions offered.  While cranking the en.gine the ROTOR dose turn ,the Points open and  close, the gap is correct according to the manual.

If the timming chain is broken or has jumped some notches should you still be able to get a spark?

 

Many thanks for all your input it really helps,

 

Bruce

[TerryB]

Yes, as long as the points open and close, and you have battery voltage to the coil and a good grounding of that current flow though the coil when the points are closed and a decent condenser, you should get a spark at least out of the coil.  

[TerryB]

The timing chain controls the opening and closing of the intake and exhaust valves by rotating the camshaft. The lobes on the camshaft open the valves when the cam lobe puts pressure on the end of the valve stem. When the lobe continues it’s rotation it then takes away the force on the valve and the valve spring then holds the valve closed.  

If the valves are not opening and closing as they should be, the engine will not start.  There will be spark however if the points open and close and everything electrical and mechanical associated with the coil and points is working as it should.  The spark at the spark plugs has no gas mixture to ignite in the cylinders so the engine will not run if the valves are not functioning. 

[Bud Tierney]

Unless I missed it in reviewing the thread, I don't see any info re' history...

Is this a running car that suddenly quit on you???

If so, fif it develop any running problems before ir quit completely??

Or id this a barn or field car, not run for ???years, that you;re trying to resurrect to drive home??

[c49er]

Yes ...

We need to know whatwhen and how this problem occurred.

These flatheads are really simple.

You need compression, fuel and good spark.

Close timing and the engine should run.

[keithb7]

Next steps involve a multi-meter. Do you have one? Know how to use it?

[keithb7]

You may want to watch these videos I made. 
 

 

 

 

[49-P15]

these old engines are pretty much bullet proof.  There are a lot of good suggestions on how to verify that the timing stuff is operating and that the rotor is turning.  Oddly enough the condenser (Capacitor) is critical to getting a spark.  I dicked around for a week with everything out of the car on on the bench but no spark.  I didn't think the condenser was necessary.  I still know 't know why, but it is. 

 

They are cheap and plentiful.  

[Oldtech]

To attempt a simple answer about the condenser. The condenser is an electrical shock absorber.  When the points open and the magnetic field in the coil collapses, it sends a pulse back to the points, which would cause a spark at the points. We don't want that, so the condenser absorbs that pulse.. About that time the spark occurs and the pulse on the points actually depletes to nothing. The condenser releases the energy that it just stored and adds to the coil primary, giving a better spark. If you have no condenser you will usually get 1 spark when you first rotate the distributor, then almost nothing after that.  So yes, you need a working condenser.  Hope this is an understandable explanation without the engineering lesson. 

[halifaxhops]

On 10/22/2021 at 9:36 PM, Oldtech said:

To attempt a simple answer about the condenser. The condenser is an electrical shock absorber.  When the points open and the magnetic field in the coil collapses, it sends a pulse back to the points, which would cause a spark at the points. We don't want that, so the condenser absorbs that pulse.. About that time the spark occurs and the pulse on the points actually depletes to nothing. The condenser releases the energy that it just stored and adds to the coil primary, giving a better spark. If you have no condenser you will usually get 1 spark when you first rotate the distributor, then almost nothing after that.  So yes, you need a working condenser.  Hope this is an understandable explanation without the engineering lesson. 

Great explanation.  I rebuild just Mopar distributors and the "new" parts store parts suck bad.  The condensers either open or short out shortly after installation and the points have really weak spring tension.  I only use NOS/NORS parts.  Simple check on the condenser take the lead off and crank it to see if you have spark.  Do not run it that way you will burn the points out quickly.  Also make sure the contact area of the points is flat and clean.  Just FYI