Points,,any advantage with smaller plug gaps?

[Turboomni]

Found out my car was setup all wrong. Vacuum advance on manifold vacuum,,4 degrees base timing. In any case she has now a new ballast resistor ,condensor,points , a new 6 volt coil, wires and vacuum advance now on ported vacuum on the Edelbrock 1406. Base timing is now at 12 +. She has never run better. Wondering if it can't hurt or help to reduce the plug gap from 035 to 030 to keep the points happy without hurting performance,,,or does it matter>?
Figuring a 6 volt coil and points would be happier with the smaller gap.
I remember reducing gap on my Omni when running 20 psi but my 440 is a low compression engine and is why I ask. Will a smaller plug gap help point life and will it hurt power? I figure with a low compression engine a spark is a spark.
Thanks

 

[Davea Lux]

A smaller plug gap will have no appreciable effect on point life. Points wear on the contact surface from electrical arcing each time they open and close. When the points are open, ground is removed to the coil which collapses a magnetic field. and a spark is produced and this is independent of the plug gap. A tighter plug gap will create a shorter, more intense spark. This will tend to cause the plug electrodes to erode more quickly than they otherwise would. The other effect with a tighter plug gap is that fuel is less likely to be ignited due to the smaller surface area of the spark arc. This can lead to a misfire which will adversely affect performance.

Automotive companies spent a good deal of engineering time and money trying to create ignition systems that had good life in the real world, and by and large, they did a pretty good job, so I would not recommend altering the factory settings or components unless one is going to do a full electronic ignition conversion. Electronic ignition is nice to have when it works, but it can fail suddenly and leave one stranded. I kept points in most of my Mopars and carry a spare set in the glove box, that I know I can fix on the road.

Dave

Corrected

 

[CBODY67]

(440 with a "6 volt" coil?)

 

[Turboomni]

(440 with a "6 volt" coil?)

I heard using a 12 volt coil on a points ignition would not work very well unless you removed the ballast resistor. Without the ballast resistor the points would burn out quickly.

 

[Turboomni]

Thanks Mr Lux. Now that I think about it even if the plug gap was too big or small the load going through the points doesn't change.

 

[Turboomni]

When the points are closed, ground is supplied to the coil which collapses a magnetic field.

I thought it was the opposite? When the points open and disconnects the ground to the coil the field collapses and creates the spark? Maybe I have it backwards.

 

[Davea Lux]

I thought it was the opposite? When the points open and disconnects the ground to the coil the field collapses and creates the spark? Maybe I have it backwards.

The old school way to test a coil was to disconnect the distributor lead from the coil. Use a pair of alligator clips one to the negative (Distributor) side of the coil. The other lead is touched momentarily to ground and the coil should spark every time the lead hits ground. Been 40 years since I was taught the theory of operation, so I do not remember if the field collapses as the ground is supplied or removed. I will look it up and report back later.

Dave

 

[Davea Lux]

I heard using a 12 volt coil on a points ignition would not work very well unless you removed the ballast resistor. Without the ballast resistor the points would burn out quickly.

The factory circuit to the coil is a two path system. One lead goes to the ballast resistor, this is the lead that is active with the ignition in the "run" position. The other lead provides 12v to the coil when the ignition is in the "start" position. Automakers used this system to prolong point life as the engine needs less spark once it is running and the lower voltage going thru the points at run causes less metal to be eroded from the points. The other benefit was that less windings were required to build the coil at lower voltages. That saved the automakers money and kept the coil from overheating running at 12v. I always suspected that the automakers probably made this choice during the transition from 6v to 12v to save having to redesign all of their ignition systems.

Dave

 

[70bigblockdodge]

Coil works off of winding ratio. Amperage creates magnetic field, opening circuit (no electron flow) the field collapses over the secondary windings (no electrical connection) causing the high voltage low amperage spark, to jump the spark plug gap. Can be visualized using the right hand rule for electromagnetic field, look it up.
Coil can run on either voltage the amperage is what causes the coil to get hot, example is car will run hot wired to the battery. Amperage is regulated by the ballast resistor voltage drop to not beat the hell out of the points, also allows coil to run at it's designed voltage when starter is engaged by bypassing the ballast resistor. In Mopar electronic ignition the coils remained the same because they worked. Of course if your a giant like GM you can change stuff and the aftermarket must keep up.

Short answer is no it will not help your points or make it run better. If your ignition is working, that's it you lit the fire, job done.

 

[Turboomni]

Coil works off of winding ratio. Amperage creates magnetic field, opening circuit (no electron flow) the field collapses over the secondary windings (no electrical connection) causing the high voltage low amperage spark, to jump the spark plug gap.

So your saying when the points open and the ground to the coil is disconnected and nothing is going through the coil the field collapses and the other separate winding sends a high voltage to the plug.
That's how I understood it.

 

[70bigblockdodge]

So your saying when the points open and the ground to the coil is disconnected and nothing is going through the coil the field collapses and the other separate winding sends a high voltage to the plug.
That's how I understood it.

Yep, technically it transforms the low voltage, high amperage current into high voltage, low current. Opposite of what happens on the utility pole out in front of your house (or nieghbors), the there high voltage low current is turned into your 110( low voltage) high current to power your wife's hair dryer.
They don't need points to break the circuit and collapse the field, the 60 cycle alternating current does it for them.

 

[Davea Lux]

The points opening causes the field to collapse, you had it right.


Dave