Ferret plugs, coil and dizzy stuff

[fv1609]

Andrew ok. I relented & reinstated the ballast short circuiting arrangement as I had some cold starting problems. The whole point being is that whilst cranking the voltage available is going to drop depending how well charged your batteries are & every chance should be given to get as good a spark as possible under these circumstances. Incidentally I have now disconnected my choke as it is no longer needed.

 

Yes splicing into 'R' seems fair enough. It was easier on the Humber as I fed this wire through a pipe that was the vent from the distributor to the crankcase breather but instead I have directed it off towards the switch panel.

 

He was keen to sell me a high performance coil. I don't know if a matching ballast resistor was suggested for use on 24v. But I have reservations about using such a coil on the B60.

 

As I understand it the HT that you derive from the coil is dependant on the magnetism you can build up in the coil before the magnetism collapses as the points open.

 

The magnetism built up is determined by the current allowed to flow into the coil which then has to be switched off by the points. There is a practical limit to how long points can last continously switching a current of several amps. So the design of conventional coils is limitited by the ability of the points.

 

Once you dispense with points & switch the coil current on & off electronically then greater currents can be used. This means a coil can be made to produce more HT by carrying a greater current in the primary winding.

 

A conventional coil in the B Series will have a resistance of 3.8 ohms, whereas a high performance coil intended to by used with electronic ignition might be 2.5 ohms.

 

BUT if you use the existing ballast resistor you will have reduced HT!

 

In the normal setup the coil resistance = ballast resistance, so that the coil receives 12v from the 24v supply.

 

This ratio changes when you have a high performance coil with accompanying lower resistance. It means more current will flow, but that will mean more voltage drop accross the ballast resistance so there will be less voltage to the high performance coil. So that it will then give less HT than you were expecting.

 

If you have a matching ballast resistance to the new fancy coil then that will be fine. Incidentally I would be interested to know what the resistance is for the new coil. If you want to use the new coil you will need a ballast resistance with the same resistance as the coil. But a replacement is unlikey to have the temperature characteristics of the original ballast resistance combination that presents a lower resistance when the engine is cold to provide a bit more HT when it is needed.

 

Incidentally don't follow his advice about increasing the sparking plug gap, if you have RSN13P the platinum contact will ping off if you try to adjust it.

[fv1609]

This is how I got the 24v + supply to the module, by feeding it through & re-routing the distributor breather tube.

 

[Andrew S]

Clive,

Thanks for the info. Turns out I am missing a matched resistor for the coil which is now on its way.

Does the breather tube still breathe ok in its new position? Did you have to add conduit to the tube to get beyond the engine compartment?

 

I am hoping to make a connection from the junction box to supply the coil and jolley plate with 24 v. The coil will have resistors in series to cut voltage to 12. I guess it would not hurt if I made a small hole in the breather tube and branched off from it to get to the junction box with the Jolley plate power lead. That would at least get me out of the distributor with the wire.

 

Andrew

[fv1609]

Andrew, pleased some good has come from my ramblings. It surprised me that a new fancy coil was supplied without a matching ballast resistor for 24v operation.

 

I would be interested to know the resistance of it & the price! I would also be interested to know the resistance of the secondary winding, they normally seem to be in the order of 7 kilohms.

 

The values of electronic ignition coils is even lower than I had imagined. Looking in a SEME instructional booklet, it quotes a conventional 12v coil primary as 3-5 ohms & an electronic ignition coil as 0.6 - 0.9 ohms.

 

That should give a significant boost to the HT output. Although with this will come a greater chance of insulation break down somewhere in the screened system & the distributor with voltages it was not originally designed for. I have noticed that the leakage even on a NOS rotor arm can be halved by leaving it out in the sun on a hot day. Although in practice a hot engine would sort that out, assuming you can get it to run initially.

 

The breather pipe had an awkward bend in the end termination to connect to the crankcase. As it was too short for its new role, I replaced it with a proper electrical lead with a termination that matched the distributor. But even so that was too short & you can see the join halway along its length.

 

There is enough gap for it to breathe as it wants through the end. The crankcase breather port is just open. As I'm not doing deep wading, I just left it open.

[Andrew S]

Clive,

Actually the resistor was meant to be included but got left out of the package. Now one is on its way in the mail.

 

Having thought about this a bit I think this is what I might try to do.

 

Remove the old coil but leave the end part where the wires to hold the end of the new coil and also to take advantage of the wire conduits attached to it. I have a bracket to hold the body of the new coil in place.

 

I will move the ignition wire from the ignition post to the R post to eliminate the ballast resistors. This will serve to power the coil and the jolley plate.

 

I will see if I can thread the red wire of the jolley plate through the braided conduit the negative wire to the coil from the distributor lives in. I will then splice power for the jolley plate and the coil from the original ignition wire connected to R in the junction box. (putting the new resistor in series for the coil)

 

Only tricky part will be to see how easy it is to get the second wire down from the distributor to the coil through the braided conduit.

 

If I remember right the coil cost about 40 pounds sterling (at least cheaper than a NOS original coil)

I also bought a NOS rotor arm so I will start fresh with that.

 

I do have a digital multimeter so hopefully I can take a few meaningful measurements.

 

Andrew

[fv1609]

Andrew yes the top of the coil assembly lends itself to transplanting to another coil. Where were you intending to put the new ballast resistor? I'm intrigued to find out what this will be & where you are going to mount it, if you are trying to make it as descrete a conversion as possible.

 

If the fancy coil is a really powerful one then its going to be as little as 1 ohm. If its a 12v coil the ballast resistor must also be 1 ohm, therefore a current of 12A will flow. Therefore the resistor must have a dissipation of 144 watts, which is going to be quite something.

[Andrew S]

Clive,

I am not sure what shape or size the resistor is. I am hoping It migh mount beneath the coil somewhere out of sight.

Andrew

[Andrew S]

Clive,

Where did you get the extra braided wire conduit? I was thinking of using a spare port inthe ignition coil head part to connect another braided wire to take power to the new resistor (maybe in a small box) and then also back to the coil. That way to the untrained eye it will look like it was meant to be that way and it will leave me leeway on where I mount the resistor.

 

Thanks,

 

Andrew

[Andrew S]

Andrew yes the top of the coil assembly lends itself to transplanting to another coil. Where were you intending to put the new ballast resistor? I'm intrigued to find out what this will be & where you are going to mount it, if you are trying to make it as descrete a conversion as possible.

 

If the fancy coil is a really powerful one then its going to be as little as 1 ohm. If its a 12v coil the ballast resistor must also be 1 ohm, therefore a current of 12A will flow. Therefore the resistor must have a dissipation of 144 watts, which is going to be quite something.

 

 

Clive,

It is still a work in progress. I think I can mount the new resistor easily under the oil cooler so it will be out of site. Here is a photo of where it will be (oil cooler removed.) the resistor is the T shaped thing. Not bolted tight in the photo.

 

I also found the braided wire conduits are made only for one wire. I am getting a spare & will try drilling the hole in the end bigger to accomodate more wires.

 

Andrew

 

 

[fv1609]

Andrew, well the resistor looks fairly robust. Although I said it must dissipate 144 watts, in reality it will be less than that as the current is only flowing when the points are closed of course. I would be interested to know its actual resistance.

 

I assume you have removed the lead that shorts out the ballast resistor when the starter motor runs? Otherwise that would be quite a current for the new low resistance coil to handle.

 

For my module supply I used similar looking screened cable from some other application.

[Andrew S]

Hi Clive,

 

My understanding of the install from my discussion with Frank Jolley is as follows.

 

The new coil plus is connected through the new ballast resistor to 24v. I am assuming this indicates the coil is designed to work at 24v. The new ballast resistor is 1.82 ohms.

The old ballast system is completely out of the circuit.

 

The Jolley plate is also connected to 24v.

 

So in essence I am completely bypassing the old ballast resistor setup. I did this by placing a wire from the R terminal to the ignition wire terminal in the junction box. In my case I was not sure if the old coil or the ballast reistor were the cause of my ignition problem.

Now I have taken the cover off the junction box I am thinking it may have been the old ballast resistors as they are pretty corroded. The photos show the corrosion on the resistors. Also the red wire is the jump wire I put in to bypass the ballast resistors. I checked the voltage with the jumper in place and I am getting 24v now on the ignition wire. I would have liked to replace the junction box with another one I have which is in good shape but it looks like too much of a pain to swap it out. I think the wires are ok so it probably does not matter.

Another problem I had was changing out the connector on the coil HT wire. The ferret had a screw in cap. I got a rubber boot to fit and made a new contact to fit as well.

 

Andrew

 

 

[fv1609]

Andrew, oh well yes I see why there were problems with the ballast resistors. Certainly wise to side step that lot & keeping the new resistor away from the wiring in there, so that the BST wiring doesn't short the new resistor out during start up. A new junction box would be worth looking out for if at some stage you decide the fancy coil is more trouble than it is worth.

 

Looks like it's been letting the moisture in for some considerable time. Were the lid screws not fully tightened, as the rubber gasket looks quite stained?

 

So is the new coil 1.82 ohms as well?

[Andrew S]

Clive,

Fortunately I have a spare junction box so I could replace it whenever. Unfortunately looks like a pain to remove as I would have to remove the air intake pipe to get at it fully. The o ring seal seems dry but it was quite tightly screwed down. I had to pry it apart once I removed the nuts. I think I will reseal it with some dielectric grease or silicone liqid gasket to keep moisture out although the wires and connectors look ok it is just the ballast resistors & the conncecting bar that look bad. Wonder why they did not use brass or copper? I cleaned off the terminals as best I could around the ballast resistors & covered the metal with dielectic grease to protect it although iit will no longer be needed in the circuit.

I bypassed form the R terminal to the ignition wire and I am getting a 24v reading from the ignition wire so it looks good. If I am correct on the wiring the ballast bypass circuit will not make any difference as it will all be 24v. My new resistor is going to be wired into the ignition wire downstream anyway so it will always ne in the circuit. I am just waiting on a new braided conduit I bought so I can find a way to get more wires through it without messing up the original. I am being very careful to make everything I do completely reversible if I ever wanted it back to stock.

 

If I am measuring right the coil has a resistance of 3.3 ohms. Not sure exactly the physics behind the coil reistance and the new ballast resistance.

 

Andrew

Here is a primitve diagram of what I am doing. The ignition wire will be my connect to 24v and I will have that supply the resistor/coil and the Jolley plate.

The pos and neg wire to the Jolley plate will hopefully go in the braided conduit from the distributor to the coil housing where the connections will be made. I will make a hole in the conduit to branch a wire to and from the resistor.

[fv1609]

Andrew, your circuit looks fine. Seems odd that the ballast resistance is now about half that of the coil. The advantage of the old system was that by loading the circuit with a resistance equal to that of the coil it offset some of the effect on the inductance of the coil.

 

In that 12v plus equal ballast resistance gives more effective HT output than a 24v coil alone. Some of that advantage has been lost now that the resistance added is only half the resistance of the coil. Although the coil now will be receiving not 12v but more like 18v. So it will be drawing more current so maybe that wil be sufficient to compensate?

[fv1609]

Seems odd that the ballast resistance is now about half that of the coil. The advantage of the old system was that by loading the circuit with a resistance equal to that of the coil it offset some of the effect on the inductance of the coil.

 

In that 12v with equal ballast resistance gives more effective HT output than a 24v coil alone. Some of that advantage has been lost now that the resistance added is only half the resistance of the coil. Although the coil now will be receiving not 12v but more like 18v. So it will be drawing more current so maybe that wil be sufficient to compensate?

 

[Andrew S]

Clive,

I emailed Frank for tech specs on the coil/reisistor but did not hear back yet.

 

On a postive note I got the system installed and it runs great. I ended up mounting the resistor on a bracket nect to the coil attatched to the original coil head housing.. The only visible alteration to the engine is the new coil itself, the reisistor and a new wire to the resistor all of which are hidden fairly well by the oil cooler. The resistor is on a bracket that runs parallel to the body of the coil about 2 inches away.

 

 

 

 

The distributor side does not have any visible changes. Aside from the standard spark plug connectors.

 

 

Andrew

[fv1609]

On a postive note I got the system installed and it runs great.

 

Andrew thats good news. I have to admit that I'm still intrigued by the design voltage intended for this coil & that it will be getting much more than 12v. The time constant will be higher than in the original RR setup as that is dependant on the inductance divided by resistance. So although this coil may be drawing more current to create a greater magnetic field, if the time constant has increased, at the highest speeds the magnetic field would not so readily collapse as in the RR design with a ballast resistor equal to the resistance of the coil.

[john fox]

has Jolley addressed the overheating problem for the new coil?

 

IIRC one of the Americans who fitted the "electronic" coil in the original housing found it failed very quickly, which was diagnosed as inadequate cooling for the coil, and feedback from Jolley said it should not be fitted in the housing but should be mounted outside?

 

then again I do have the distinct feeling that we are doing his product testing for him and anyone who bought an earlier model of his kit would not get the same now, as he incorporates the latest feedback on why their earlier version failed (but does not pass that on to the original customers).

Yes I have an original kit, but I have not used it yet, I await your user "trials" results with interest !

[Marmite!!]

IIRC one of the Americans who fitted the "electronic" coil in the original housing found it failed very quickly, which was diagnosed as inadequate cooling for the coil, and feedback from Jolley said it should not be fitted in the housing but should be mounted outside?

 

 

On the B-Series engines the coil is mounted on the outside, it's only the top of the coil that is enclosed, can't see how you would get overheating problems with just the top covered..

 

then again I do have the distinct feeling that we are doing his product testing for him

 

Isn't that the same with a lot of new products??

 

Photo from Clive's http://www.hmvf.co.uk/pdf/IGNITIONMATTERS.pdf

Edited June 11, 2010 by Marmite!!

[Andrew S]

has Jolley addressed the overheating problem for the new coil?

 

IIRC one of the Americans who fitted the "electronic" coil in the original housing found it failed very quickly, which was diagnosed as inadequate cooling for the coil, and feedback from Jolley said it should not be fitted in the housing but should be mounted outside?

 

then again I do have the distinct feeling that we are doing his product testing for him and anyone who bought an earlier model of his kit would not get the same now, as he incorporates the latest feedback on why their earlier version failed (but does not pass that on to the original customers).

Yes I have an original kit, but I have not used it yet, I await your user "trials" results with interest !

 

John,

I had thought about the cooling issue but it is only the very end of the coil ( The lip at the end of the coil and the terminals), that is enclosed. The rest is open to the air to cool so I cannot imagine it would be a problem as 95% of the coil is exposed. The part that is enclosed is mostly plastic. The rear bracket is metal and should conduct heat ok. I guess if it became an issue I could remove the end cap of the housing as well. Then it would all be open to air. Maybe Frank Jolley thinks the whole coil is encased by the housing? The original coil is in a thicker casing to waterproof it.

 

I did some short test runs today and seems to run great. I have not checked my spark plug gaps yet to see if they are the recommended spec.

 

Andrew

[Andrew S]

On the B-Series engines the coil is mounted on the outside, it's only the top of the coil that is enclosed, can't see how you would get overheating problems with just the top covered..

 

Isn't that the same with a lot of new products??

 

Photo from Clive's http://www.hmvf.co.uk/pdf/IGNITIONMATTERS.pdf

 

Lee,

Just saw your post. Basically what I am saying too! The only modification I made to make my coil fit the housing was I put a small collar of neoprene to make it fit snug but it is not very wide so not much of a heat issue. I suspect some are thinking the coil is more enclosed than it is.

 

Andrew

[fv1609]

Introducing more inductance than resistance with the new fancy coil & its ballast resistor will bring about a disadvantageous time contstant which will reduce HT output at higher speeds.

 

We have now an arrangement that undoes some of the advatages that were so carefully designed into the system in the first place.

 

Looking at the DC activity of the new system we have a new fancy coil with a resistance of 3.3 ohms with a ballast resistance of only 1.82 ohms. This gives a total resistance of 5.12 ohms, when supplied with 24 volts by Ohms Law it means a current of 4.7 amps will flow through the coil. The power dissipated (heat) in this coil is 73 watts.

 

This a cautious calculation, because when the system is in normal running & charging the voltage supplied will not be be 24 volts but 28.5 volts. Working out the power dissipated it comes to 102 watts. This is a lot of heat to dissipate on a very hot engine.

 

Applying the same calculations to the original RR installation at 24 volts the power dissipated in the coil is 38 watts & when on 28.5 volts the power dissipated rises to 53.6 watts.

 

So we are introducing a system that now has a coil in it that is creating double the amount of heat (102 watts) compared with the original coil that dissipated 53.6 watts. I have no doubt that "it works" in delivering HT, but no wonder it gets hot!

 

I am intrigued as to the design working voltage of the new fancy coil. In the proposed set up with the ballast resistor supplied the coil will be working off 18 volts. I was unaware that coils are made for a strange voltage like this. Ignoring the inductance/resistance time contstant issue for screened miltary systems, my understanding is that coils for use with a ballast resistance were purely for an "easy start" voltage. A coil might be designed to run off say 10 volts with a ballast resistance in series the system would normally be supplied with 12 volts.

 

At start up the starter motor may cause the nominal voltage to drop to 10 volts. The starter switch would short out the ballast resistance so there is no detrimental drop in HT output when it is most needed. The RR system applies the full 24 volts to the coil bypassing the ballast resistances during the start up phase, but allow the resistances back into circuit once started.

 

So we need to know the design working voltage of the new fancy coil. If it is not designed to work on 18 volts & is in fact a 12 volt ( or I hope not a 10 volt) coil why doesn't the ballast resistance match the coil resistance? Because not only is the time constant disfigured from the original design but the fancy coil is dissipating double the heat of the earlier coil.

 

Ballast resitances in civilian ignition systems are for improved cold starting & although this feature is incorporated in the RR system, the important issue for a screened HT system is the improved time constant to allow the magnetic field in the coil to collapse & deliver the maximum spark.

 

As yet I can see not benefit in providing a poorer time constant & coil that now gets twice as hot. Having said all that, the electronic ignition module itself is a superb device in terms of ingenuity & its contstruction. I have bought two such modules & am very pleased. I would strongly advise others with B Series engines to take advatage of the module, which although is expensive will prove to be a very worthwhile modification. But on the present evidence a new coil & its ballast resistance seems a mod too far.

[Andrew S]

Clive,

Not sure about the physics of it but it seems to run great. No problems so far. That being said I only drive it 10-15 miles at a time so can only attest to performance to that point.

 

Andrew

 

 

Introducing more inductance than resistance with the new fancy coil & its ballast resistor will bring about a disadvantageous time contstant which will reduce HT output at higher speeds.

 

We have now an arrangement that undoes some of the advatages that were so carefully designed into the system in the first place.

 

Looking at the DC activity of the new system we have a new fancy coil with a resistance of 3.3 ohms with a ballast resistance of only 1.82 ohms. This gives a total resistance of 5.12 ohms, when supplied with 24 volts by Ohms Law it means a current of 4.7 amps will flow through the coil. The power dissipated (heat) in this coil is 73 watts.

 

This a cautious calculation, because when the system is in normal running & charging the voltage supplied will not be be 24 volts but 28.5 volts. Working out the power dissipated it comes to 102 watts. This is a lot of heat to dissipate on a very hot engine.

 

Applying the same calculations to the original RR installation at 24 volts the power dissipated in the coil is 38 watts & when on 28.5 volts the power dissipated rises to 53.6 watts.

 

So we are introducing a system that now has a coil in it that is creating double the amount of heat (102 watts) compared with the original coil that dissipated 53.6 watts. I have no doubt that "it works" in delivering HT, but no wonder it gets hot!

 

I am intrigued as to the design working voltage of the new fancy coil. In the proposed set up with the ballast resistor supplied the coil will be working off 18 volts. I was unaware that coils are made for a strange voltage like this. Ignoring the inductance/resistance time contstant issue for screened miltary systems, my understanding is that coils for use with a ballast resistance were purely for an "easy start" voltage. A coil might be designed to run off say 10 volts with a ballast resistance in series the system would normally be supplied with 12 volts.

 

At start up the starter motor may cause the nominal voltage to drop to 10 volts. The starter switch would short out the ballast resistance so there is no detrimental drop in HT output when it is most needed. The RR system applies the full 24 volts to the coil bypassing the ballast resistances during the start up phase, but allow the resistances back into circuit once started.

 

So we need to know the design working voltage of the new fancy coil. If it is not designed to work on 18 volts & is in fact a 12 volt ( or I hope not a 10 volt) coil why doesn't the ballast resistance match the coil resistance? Because not only is the time constant disfigured from the original design but the fancy coil is dissipating double the heat of the earlier coil.

 

Ballast resitances in civilian ignition systems are for improved cold starting & although this feature is incorporated in the RR system, the important issue for a screened HT system is the improved time constant to allow the magnetic field in the coil to collapse & deliver the maximum spark.

 

As yet I can see not benefit in providing a poorer time constant & coil that now gets twice as hot. Having said all that, the electronic ignition module itself is a superb device in terms of ingenuity & its contstruction. I have bought two such modules & am very pleased. I would strongly advise others with B Series engines to take advatage of the module, which although is expensive will prove to be a very worthwhile modification. But on the present evidence a new coil & its ballast resistance seems a mod too far.

[fv1609]

Clive,

Not sure about the physics of it but it seems to run great. No problems so far. That being said I only drive it 10-15 miles at a time so can only attest to performance to that point.

 

Andrew

 

Andrew well that's good news. How hot did the coil get & have you had a chance to measure the voltage being applied to the coil? Has Mr Jolley responded to the points raised about the differing resistances of the coil & that of the ballast resistor? One is tempted to wonder how much things would have improved anyway by just replacing the ballast resistors with non-corroded ones.

 

But who knows you may now have a more potent HT source than the rest of us. Will you be bringing it to W&P as it would be interesting to measure the HT at differing speeds. I made up this to allow me to capacitively couple to a HT lead.

 

 

So that I could use this.

 

 

In the 1,000 rpm range mine runs around 12 KV.

 

 

Obviously the speed, mixture, state of plug etc will have an effect on the resultant HT. The highest voltage being with the plug disconnected I was getting 27-30 KV

 

 

I would be interested to compare readings on other B60s with & without electronic ignition to get a feel of how things should be. If I had more time I would like to put in a non-screened system to try to measure how much HT is actually lost due to the capacitance of the screened cables.

[Andrew S]

Hi Clive,

Unfortunately W&P is too far for me to bring my Ferret as I live in USA. I emailed Frank to see if I can get some specific data to share. One other thing I am going to do is replace the original ignition wire. I had Frank make me a set for the coil and spark plugs. This will give me a better connection to the coil than the connection I made myself.

Too bad I cannot make W&P would be great to have you figure out the specifics on the coil.

 

Andrew