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Installing Sport Coil - Help Please

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DerekJ

DerekJ

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Hi guys

I am ignoring the "if it aint broke dont fix it" rule for some "preventative maintenance".

Im installing a new Lucas sport coil but I dont like electrics!

The old coil terminals are marked CB & SW whereas the Sport Coil is marked + and - .

The CB terminal takes the black & white wire to the distributor. Qustion is - On the sport coil is this the + or - to the distributor?? /ubbthreads/images/graemlins/confused.gif

My car is still POSITIVE EARTH.

BTW the old coil appears very old! The aluminium casing is very battered and pock marked. The coil has a red screw-in top and stamped on the bottom is

HA 12
45054
5 58

My car was made in 1958, is it possible this is the original coil!!!
 
Hi Derek,
Since the coil was built in 5/1958, it's likely to be an original. They seem to last forever.
(-) would correspond to (sw) & be connected to the switch. (+) would correspond to (CB) & be connected to the points. V/S for a negative ground car. Sport coils of the era were marked DLB105 & had CB & SW markings & a red top tower. Later versions may well be marked (+) & (-).

Actually, the only benefit of a correct connection as opposed to reversed is that with the correct connection, the plugs will require a bit lower voltage to fire. (A thing related to current flow direction & plug electrode temperature.)

I still have a perfectly good HA12, marked 45075D, 8 58 that I replaced with a Pertronix # 40611 just because of the coil's advanced age & the fact that I was switching to Pertronix ignition. I did mount the coil on the foot well instead of the engine, just for a cooler & more vibration free location, & to avoid the tight quarters for the vacuum advance line.
D
 
Thanks Dave,

Here is another question. I did some list searches and read that its necessary to route a new wire. Something to do with the Ballast system being different in the new coils. Is this correct and if so what is it I have to do?

I just know I'm going to regret this change ... If it aint broke.....

thanks again
 
Hi Derek,
I'm not sure what you are reading. No new wire that I'm aware of.
Healeys do not have a ballast resistor. They should use a coil rated for use WITHOUT a ballast. A proper coil for the car would have a primary winding resistance of 2.6 to 3.3 Ohms.

Some of the coils which are suitable for use on a stock non-ballasted Healey:
Lucas HA12 with 3.1 Ohms primary resistance
Lucas Sport DLB105 with 2.6 Ohms
Lucas LA12 with 3.3 Ohms
Lucas 11C12 with 3.0 Ohms
Pertronix 40501 with 2.8 Ohms
Pertronix 40511 with 2.8 Ohms
Pertronix 40611 with 2.8 Ohms

Coils suitable for use with a ballast only (NOT HEALEY):
Lucas 16C6 with 1.3 Ohms
Lucas DLB102 with 1.5 Ohms
Pertronix 40011 with 1.2 Ohms
Crane PS20 with 1.4 Ohms

Use of a coil that has less than about 2.6 ohms & without a ballast will burn the points in short order. But since many coils are available for use on non ballasted systems, there is no need for a low resistance coil with it's required ballast.

Not to say that you could not use a low resistance coil by adding a ballast & associated wiring changes but I see little gain in doing so.
D
 
I'll add my 2 cents worth. An ignition coil has two [2] internal windings and just three [3] terminals, two [2] low voltage and one [1] high voltage output. The 'SW'[switch] terminal is internally common to both coils, a] the primary winding which has thin wire with many turns and produces the magnetic field, and b] the secondary winding which has heavier wire and few turns. The 'CB'[circuit breaker] terninal is connected to the other end of primary winding. The centre high voltage terminal is connected to the other end of the secondary winding. When the voltage is applied to the SW terminal and the contact points are closed current flows through the primary coil producing a magnetic field. Once the point open the magnetic field collaspes producing a current in the secondary winding which is directly proportional to the ratio of the number of windings in each coil thus the high voltage output out the centre termial. But remember that in order for this high voltage energy to be directed to the spark plug, electricity is lazy, it must have a pusher, and this is where the internal connection of the other end of the secondary coil via. the 'SW' terminal provides. Reversing the connection provdes too much resistance to give the big push necessary.
I installed a Pertronics on a friends MGB, and it worked find for 2 years. Went to Watkins Glen last Sept for the festival, car would not start. Worked almost four [4] hours to try to get it running - fuel system OK, air OK, spark was there but weak, would shock you if you held the lead, a false signal. After rechecking everything, carbs off & apart etc. I tried to get the spark to jump to ground a snap, but it would only jump a 0.100" gap without any punch. Not sure how the internals work but in theory they put the Pertronics to interupt the power feed, to the 'SW' terminal and ground both primary and secondary windings - no push. In deperation I reinstalled the old point system, which once removed was put into a baggy and stored in the glove box - first turn of key and it fired right up, however too late to take in the festivities. The Pertronics is still on the shelf collecting dust, replaced this spring by a $5 set of new points.

Regards, Bob
 
RF, Me thinks you need a refresher in tranformer design.Keoke /ubbthreads/images/graemlins/yesnod.gif
 
If it aint broke don't fix it !!!! /ubbthreads/images/graemlins/lol.gif

What did I tell you. Went down to the car just before dinner, what could be simpler than installing a coil, a few simple nuts and everything is easily accessible.

Started up no problem.....until I then heard a strange clicking noise. This appears to be coming from the distributor. Everything looks ok... same as before so whats happening....is the extra voltage doing something to the points. I'd no time to check so I shut her down. Should I open the points gap? What else could make that noise? /ubbthreads/images/graemlins/confused.gif
 
Well Derek, I can not be sure, but it sounds like you may have tracking in the distributor cap but it should show up as a miss also. Be sure you have the coil connected properly as Dave indicated earlier.If by chance you got it the wrong way around the higher break down voltage cold also cause the problem and check the carbon post in the center of the Dist cap and be sure it bears down correctly on the rotor. Might give the rotor a good look at and be sure it is fitting correctly too.Yes the points can be opened up to about 0.030-to-0.035"---Fwiw---Keoke
 
Hi Derek,
Check for contact between the rotor tip & the inside distributor cap contacts. Sometimes if the rotor is not completely seated down, it will be held high enough or off center enough to contact the cap terminals. Also make sure that the cap is firmly seated & centered.
D
 
[ QUOTE ]
I'll add my 2 cents worth. An ignition coil has two [2] internal windings and just three [3] terminals, two [2] low voltage and one [1] high voltage output. The 'SW'[switch] terminal is internally common to both coils, a] the primary winding which has thin wire with many turns and produces the magnetic field, and b] the secondary winding which has heavier wire and few turns. The 'CB'[circuit breaker] terninal is connected to the other end of primary winding. The centre high voltage terminal is connected to the other end of the secondary winding. When the voltage is applied to the SW terminal and the contact points are closed current flows through the primary coil producing a magnetic field. Once the point open the magnetic field collaspes producing a current in the secondary winding which is directly proportional to the ratio of the number of windings in each coil thus the high voltage output out the centre termial. But remember that in order for this high voltage energy to be directed to the spark plug, electricity is lazy, it must have a pusher, and this is where the internal connection of the other end of the secondary coil via. the 'SW' terminal provides. Reversing the connection provdes too much resistance to give the big push necessary.
I installed a Pertronics on a friends MGB, and it worked find for 2 years. Went to Watkins Glen last Sept for the festival, car would not start. Worked almost four [4] hours to try to get it running - fuel system OK, air OK, spark was there but weak, would shock you if you held the lead, a false signal. After rechecking everything, carbs off & apart etc. I tried to get the spark to jump to ground a snap, but it would only jump a 0.100" gap without any punch. Not sure how the internals work but in theory they put the Pertronics to interupt the power feed, to the 'SW' terminal and ground both primary and secondary windings - no push. In deperation I reinstalled the old point system, which once removed was put into a baggy and stored in the glove box - first turn of key and it fired right up, however too late to take in the festivities. The Pertronics is still on the shelf collecting dust, replaced this spring by a $5 set of new points.

Regards, Bob

[/ QUOTE ]

Hi Bob,
You are fairly correct up to the part where "once the points open the magnetic field collapses". Actually for the field to collapse, there must be a return circuit for current flow. This return circuit is provided by the condenser/capacitor that is in parallel with the points. The "collapse" path would be from battery negative through the coil primary winding, through the condenser, to the battery plus side, ground. The plug spark path is from battery negative, switched 12 volt terminal, the coil secondary winding, the plug gap, back to battery positive through ground.

Also the collapsing primary magnetic field generates a voltage much higher than the originally applied 12 volts, due to the very high rate of magnetic field collapse. Typically, somewhere around 100 volts may be generated in the coil primary due to the rapid magnetic field collapse. This voltage is transformed by the coil winding ratio of typically 300 to one, & becomes somewhere around 30,000 volts.

In theory, the point of common connection between primary & secondary coil windings would slightly affect coil secondary output voltage. With one of the possible connections, the "wrong" one, coil output voltage would be about 200 volts less than the theoretically correct connection. Insignificant as compared to 30,000 volts. To recap, it makes little difference whether the HV & LV windings are commonly connected on the supply side or the points side.

The Pertronix functions the same way as the points, except that the points & condenser functions are accomplished by electronics.

The fact that the Pertronix in question worked well for two years would indicate that there was nothing wrong with the basic design or connections. It is certainly possible for the Pertronix to fail, as apparently happened. The most common way is to leave the ignition switch on with the engine not running for an extended period of time.
Regards,
D
 
Just a couple of minor points regarding the previous posts in this thread...

The primary (low-tension) windings in the coil are fewer in number and use a heavy gauge wire. Secondary (high-tension) windings are made with lots turns of fine-gauge wire.

Condensers/capacitors are not conductors, they are storage devices. When the power is disconnected from the coil by opening points, current does not flow through the capacitor but the energy is stored across its plates. This is important as this action is responsible for storing the energy which otherwise would manifest itself as an arc across the points. However, the condenser doesn't have to be there for your car to run... you can remove the condenser and the car will run but with a new set of problems and quickly burned points.
 
Hi Doug,
Quote:
"Just a couple of minor points regarding the previous posts in this thread..."

"The primary (low-tension) windings in the coil are fewer in number and use a heavy gauge wire. Secondary (high-tension) windings are made with lots turns of fine-gauge wire."
--------------------
That's where the 300/1 turns ratio that I mentioned, comes from.
-------------------
Quote:
"Condensers/capacitors are not conductors, they are storage devices. When the power is disconnected from the coil by opening points, current does not flow through the capacitor but the energy is stored across its plates."
-------------------
Capacitors DO conduct current as long as the voltage level across them is changing. If it were otherwise, capacitors would never work on alternating current circuits, while in fact, they are regularly used to block DC but permit AC to flow. The coil primary charging through the points, & discharging through the capacitor is a form of alternating current. The built up coil primary voltage is collapsing to zero through the capacitor. If the capacitor were not there, the voltage change, due to magnetic field collapse, would flow through the points as an arc. Very inefficient.
-------------------
Quote:
"This is important as this action is responsible for storing the energy which otherwise would manifest itself as an arc across the points. However, the condenser doesn't have to be there for your car to run... you can remove the condenser and the car will run but with a new set of problems and quickly burned points."
-----------------
In this case, the capacitor does not store energy, it provides a path alternate to the points for the primary collapsing (changing) field voltage, to provide a quicker field collapse fhan the arcing points would, & reduces point arcing. The more quickly this field collapses, the more quickly the magnetic field cuts the coil secondary turns, & the higher the coil output voltage. It's all about di/dt.

The ignition will not work worth a darn without the capacitor. The only return path for the collapsing primary magnetic field is by an arc across the points & possibly some stray capacitance in the associated circuits. The rate of primary coil field collapse via the arc is very slow, with the resulting coil secondary voltage being very low. Kettering discovered this a very long time ago.

I have deliberately left out the mathamatical formulae & references for the sake of clarity to folks who are not familiar with engineering terms.
D
 
IF IT AINT BROKE. /ubbthreads/images/graemlins/lol.gif.......UPDATE

Went down to the car tonight and examined the distibutor in detail, Nothing apparantly wrong. I removed and replaced the carbon peg which was the only thing that has really been touched in the installation.

The loud tapping was still there although the engine was not misfiring...then I got big sparking out of the #6 plug cap.

Shut her down and carried on looking...then I noticed that both of the 'towers' on the coil had split and a piece was missing. Was this the problem?????

I replaced the old coil and started her up no problem. There is a faint clicking (more like ticking)which I think is probably normal, what do you guys think? I imagine you must be able to hear some small noise when the distributor is working, but I honestly cant say I really noticed before.

BTW I dont want to see one of those sport coils ever again.

Firstly, even allowing for my ham fisted installation how can it break like that when the old one survived 50 years!!

Secondly, they are a ridiculous colour like a cheap christmas tree ornament, it has no place in a Healey engine bay.

One piece of good news. My indicators work...traced the problem to a cunningly disguised broken wire at the fuse which at first glance was unnoticeable. I'll chalk that one up as a success! /ubbthreads/images/graemlins/thumbsup.gif

time for a beer /ubbthreads/images/graemlins/thirsty.gif
 
Dave, my mentioning the primary/secondary windings was not in reference to your post.

Regarding caps/condensers, we are saying the same thing and using different terms. When people discuss capacitors in an ac circuit they say that they "pass ac and block dc". In terms of actual current flow, the current is not going through the cap. You are filling the bucket and emptying it, out of phase with the ac voltage waveform. Current, amps, electrons, call it what you will, do not physically flow through the capacitor and across its plates. (OK, there is leakage current but it's insignificant to the overall picture here). If the cap actually passed current across the plates it would have compromised the dielectric and the capacitor becomes a wire. The current flow in an ac circuit is sinusoidal as is the voltage. Let's not add reactance and its formulas to the discussion.

I don't disagree with your rate of change statement. I stand by my comment that the condenser suppresses the arc that could form across the points. We both stated that the ignition won't work well without the capacitor. I just made the additional statement that it would run with problems and arcing. I never suggested the condenser wasn't necessary.
 
[ QUOTE ]

Regarding caps/condensers, we are saying the same thing and using different terms. When people discuss capacitors in an ac circuit they say that they "pass ac and block dc". In terms of actual current flow, the current is not going through the cap. You are filling the bucket and emptying it, out of phase with the ac voltage waveform. Current, amps, electrons, call it what you will, do not physically flow through the capacitor and across its plates.

[/ QUOTE ]
Apples, oranges, terminology differences. I said I was trying to keep it simple. I guess the cap dielectric could be viewed as a flexible rubber diaphragm in a tube. What goes in one side causes something to come out the other side as the diaphragm flexes. Of course current does not pass directly through the dielectric. However, current does flow across it. The EFFECT is the same as if the changing current were flowing through the dielectric. (Disregarding the 90 degree phase shift.) Same with a transformer with electrically isolated windings. The current impressed on one winding is magnetically coupled to the other winding, even if no current is directly passed through the dielectric. But you know this. The minute details of how this works are academic as far as how the ignition works. Enough, I hope.
D
 
[ QUOTE ]
There is a faint clicking (more like ticking)which I think is probably normal, what do you guys think? I imagine you must be able to hear some small noise when the distributor is working, but I honestly cant say I really noticed before.

[/ QUOTE ]
Hi Derek,
That clicking maybe a spark arcing somewhere. Try running the engine in the dark to check for any fireworks. /ubbthreads/images/graemlins/eek.gif I had that noise when I broke a plug wire on my Ford Ranger. Fortunately, the engine has 2 plugs per cylinder so I could still drive to the autoparts store.
 
The faint clicking/ticking might just be one of the valves (valve clearance). Use a largish rubber tube to listen around the valve area to see if that's where the noise is coming from. Watching for the fireworks in the dark is good suggestion too.

cheers,
John
 
Just don't inadvertently stick the end of the hose in the fan or belt. I Know what happens.
D /ubbthreads/images/graemlins/blush.gif
 
Guys

The faint ticking is definitely coming from the distributor. Its very consistant and regular and 'fast', not intermittant. Is that not just the normal sound the rotor makes as it revolves?

Would the broken coil towers have been causing the previous louder noise and also the sparking at the plug cap? The noise is definitely not now the same and I do not now see any evidence of sparking

thanks
 
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