Electronic ignition in a Ferret

[Manylandrovers]

Dear All, some advice please. For some time I had been thinking of converting my Humber 1 Ton to electronic ignition using the innards of a cvrt distributor. Now that the Humber is gone, I have replaced it with a Ferret I would like to test out my theory. With a spare distributor base I have swapped the electronic module into it, lengthened the cables and am preparing to swap it in. I’m pretty sure I can run a second lead inside the screened cabling from the ignition junction box, through the filter into the coil to join with the red cable coming back from the ignition module. This second lead provides the 24 volt supply to the module and will be taken off the terminal in the junction box, before the ballast resistors. 

My question is do I need to Earth the black lead from the module which is the limiter circuit for the ignition or can I do without it (rumour has it the Army often used to take the fuse out (isolating it from earth) to prevent the limiter circuit operating anyway - at the risk of overrevving clearly. ) I don’t think I will be needing it, in any case it would be set to high for the B60.???? 

I don’t think using the ignition module in reverse will be a problem.

Anything I have overlooked? If it doesn’t work I will simply swap the original back in.

Andrew

[fv1609]

Andrew the speed limiter operates when the engine speed exceeds 4750 rpm

It seems to work via a delay circuit triggering a thyristor connected across the coil primary.

I can't see that black needs to be connected to anything for the chopper module to function in its normal manner.

I have a diagram if you want.

 

 

[Manylandrovers]

Thanks Clive - I got hold of a cvrt REME electrics training publication some time ago which has the diagram, not that I understand it. Electronics I never understood at school.... 

[Richard Farrant]

The J60 in the Fox did not use the speed limiter function, so no issues there, just go along with Clive’s advice.

[Manylandrovers]

Thanks Richard - am half way through. Doing a bolt on - bolt off swap with every component that needs to swapped.ie screened leads from junction box to coil and from coil to distributor. 

[Manylandrovers]

Well it fired first time - so that’s good news. You can’t see the difference. A tad fiddly at times - it’s a lot easier with the oil cooler removed.

it hasn’t got rid of the underlying problem of only idling and not being able to rev above about 800 revs though. I’m now onto my third carb. I think I’ve work out exactly what special tools I need for this. A couple of modified spanners I think...

[Diana and Jackie]

The speed limiter has a fuse, on Belgian CVRT the fuse holder is separate to and close by the ignition coil. On British CVRT it's usually cunningly under one of the cable inlets to the ignition coil.
Unscrew the cable inlet cover and pull the fuse thus disabling the limiter, which often these days can be faulty.
Diana

[Manylandrovers]

Many thanks. I did transfer over the plug with the ceramic connector for the wire (usefully is had a separate pair of terminals which I used to connect the 24 volt feed from the ign junc box to the module, rather than a single long length of wire).

the limiter works at 4850 revs I believe which is a tad high for the b60. I might see if the OEM rotor arm will fit as that has a useful limiter built into it but at a lower speed. 

[fv1609]

Andrew I'm sure you are aware of this, but just in case, the speed limit stamped on the rotor arm is the speed of the distributor which is half the engine speed.

[Manylandrovers]

Yes but Clive it’s going the other way so should be a minus figure...

[Richard Farrant]

Have you used a complete J60 distributor or put the module in the original Ferret one? If this is a J60 dizzy  the centrifugal advance will not work due to turning  the opposite direction.

[Manylandrovers]

It’s a B60 base unit Inc weights and springs. - the drive dogs are not the same...But yes I guess you could have swapped the springs and weights from the cvrt over - I didn’t. 

[Manylandrovers]

While in the subject of electrics I see on eBay people selling Ferret Ammeters, but none of the diagrams I have show them. Were they fitted to later mks perhaps? 
im going to fit one from a landrover shunt box as I quite like monitoring the output of the generator, plus I’m going to have a BV, with the relay circuit taken from a gen + line somewhere.

Edited August 10, 2020 by Manylandrovers

[fv1609]

2 hours ago, Manylandrovers said:

While in the subject of electrics I see on eBay people selling Ferret Ammeters, but none of the diagrams I have show them. Were they fitted to later mks perhaps? 
 

Saladin had a separate illuminated ammeter panel

[john fox]

advice please...

long time ago I bought one of the first Jolley kits for a Ferret. Sadly he was still learning himself at that time and did not supply an "electronic" coil as he said the original one was OK.

I am aware that now he says you must replace the coil.

My question is: what coil should I use with the Jolley electronic system?

I am loathe to ask him as I feel he short changed me on the original deal, so don't wish to make him richer for having misled me and now needing to correct it at my additional cost. 

[Manylandrovers]

Mm, I can’t see why that it is necessary.. I don’t know if cvrt coil units were changed when they introduced electronic ignition. The housings changed as they will have had to incorporate the fuse for the rev limiter, but the coil itself? Clive will no doubt be able to tell us:-)

[fv1609]

I can see no reason to buy a new the coil. I have fitted two of these kits to Humbers without issues. At the time there was an encouragement to use a new coil but I couldn't see the point.

The purpose for me to fit electronic ignition was to improve reliability & performance by doing away with the points improving reliability & having a reliable co-ordination of the switching. The abrupt opening of the primary circuit electronically provides a higher HT output than if there is some deterioration in the condenser or points that are pitted or have an unsatisfactory gap.

The search for greater HT output seems unnecessary if the module is working as above. Greater HT can be a two-edged sword as it increases the chance of insulation breakdown with a system running at a higher voltage than it was designed for. You only have to measure the insulation of a rotor arm stored in a damp environment with the insulation measured when it has been left out in the Sun for a day when it has dried out, to see the vulnerability of components to leakage just with dampness.

Old ignition leads by now run the risk of breaking down with increased HT & once a spark has found a path established what were previously safe voltages may no longer pass without failure.

Some years ago I remember being in correspondence with someone faced with the new coil dilemma & the advice he had received but ISTR there was some fallacy I felt in the case put forward. I'll see if I can find that correspondence.

PS ISTR the advice accompanying suggestion of new coil that carries a higher primary current (because the electronic switching can handle this, which was previously limited by the maximum current the points can switch) is that a higher HT can be provided. With this increased voltage the advice was to increase the gap on the sparking plugs.

If you have RSN13P plugs do NOT try to adjust the gap as you run the risk of snapping the side electrode or worse still weakening it so that it breaks off inside the engine.

[Manylandrovers]

I agree Clive. One of the reasons I fitted mine to the Ferret was to do away with the worry of mis-synchronised points. One of my early problems in getting the Ferret to run was that it was only running on the front 3. I discovered eventually that the “bridge” between the terminal post coming in from the coil and the post for the fixed contacts (ie the bridge that runs under the baseplate) had fractured and although I soldered it I wanted to do away with that hassle. The cold staring characteristics of the electronic ignition, from my experience of J60s, is excellent. As it is, the conversion seems to have gone well. Although as I mentioned above hasn’t cured my inability to rev. (I now believe the latter is down to a seized transmission....)

The conversion took me a while to do properly - routing a second wire (made up of that rather good, thin Cvrt red LT wiring) through the armoured cabling and ignition filter (just enough space ). You wouldn’t ever know the difference. I’m going to try a conversion on My B80 using a second hand Jolley unit...

Edited August 12, 2020 by Manylandrovers

[teletech]

I'm in the process of fitting an electronic ignition to my Ferret and was wondering about the best way to set the timing.  I have read that the usual process of using a timing light isn't helpful so unsure how to proceed.

The user's manual has information about setting pint gap but noting about timing apart from "don't fool with the point synchronization" which isn't particularly helpful.

[teletech]

What worked:I used the fan to rotate the motor and looked through onto the flywheel to find the TDC marks.

Then opened up the distributor and set it to just be triggering.  Then I measured the timing with a timing light by unscrewing a plug wire and putting a metal rod in the circuit so I could use a timing light pickup.  Setting the static timing to TDC-ish yields 7 degrees of advance at 700RPM.  It idles great but I can't speak to how well it runs as yet since I'm having fuel issues so running really lean if I try to accelerate, but it's nice to have some way to measure things.