Ignition cables and connection for the elderly.

[Smallfry]

Here's a thing for the more "mature" forum members. I have a new to me old Wolseley, and am working through all the bodgery !

It has been many years since I have had a petrol vehicle, let alone one with a distributor !

Picture shows the ancient ignition coil, marked CB and SW. Not seen that for years, been marked + and - for years now ! It was a screw in, rather than push in fitting. Screwed into the top of it, is an in line suppressor, with a chunk of carbon in it, the original leads would have been non resistive, and there was no such thing as resistor spark plugs back then (I think ?)

There were two lengths of screw in fittings, and this coil requires the longer one. The suppressor is the short one, SO there is a gap of about 8mm between the contacts, which obviously isn't right.

The king lead then screws into this suppressor. Older viewers will recall that the lead threaded through this fitting, the lead then had the insulation stripped back, then was passed through a brass washer and folded over. This then screwed up tight into the coil or suppressor to make the connection.

However, this has not been done, and a push in ferrule fitted to the king lead has been jammed into the screw fitting. This is not in far enough, so leaves ANOTHER gap of about 8mm between the connections, which again, isn't right.

ISTR back in the day, that if one was having trouble starting an engine, the plug leads were pulled off the plugs and left loose, which often resulted in being able to start it ? How would this work ? Increased resistance ? This car has electronic ignition fitted in the distributor and the spark easily jumps these gaps, so my question is, How do you think all this would affect the running of the engine, and the long term condition of the HT system ?

 

[voipio]

A petrol engine wouldn't normally start, nor run, after pulling all the HT leads off the plugs. It might have been used as a diagnostic test, pulling one plug lead off at a time, to find a faulty cylinder/plug/valve, and then troubleshoot from there.

The gaps in the HT wiring don't seem right. There's normally a small gap in the distributor, between rotor arm and contacts, or course.

 

[Bladevane]

I'm an old boy also. I seem to remember (maybe incorrectly) that any increase in HT gap, i.e. by pulling leads off spark plugs and leaving them loose etc. actually strengthened the spark, therefore enabling the engine to start easier. Can't figure out why this is the case because if taken to an extreme (very large gap) the spark would be unable to jump the gap. However, I think that an 8mm gap is excessive and would definitely affect the running of the engine. Could be way off the mark here as its been donkeys since I fiddled with distributors such as yours.

 

[Cobbler]

From what I recall, the small gap forms a sort of capacitor & allows the current or voltage to build up allowing it to fire a wet or fouled plug.

 

[jack-daniels]

I remember when I was a lad (early 80's), my dads mate had a series one Land Rover with the HT leads cut in half and the conductor wrapped each side of a insulated disc to make the spark jump across.

He said it was to make it start easier. Quite the sight at night which he delighted in always showing people.

I have never seen anything like it since and would think having a gap in the coil like that won't do it much good!

 

[Cobbler]

I remember when I was a lad, my dads mate had a series one Land Rover with the HT leads cut in half and the conductor wrapped each side of a insulated disc to make the spark jump across.

He said it was to make it start easier. Quite the sight at night which he delighted in always showing people.

I have never seen anything like it since and would think having a gap in the coil like that won't do it much good!

I recall that being done with a button, the wire wrapped through the holes to provide the gap. Never tried it, but there used to be all sorts of things on sale that went into plug leads to give you 100mpg & save you a fortune. Don’t think any worked & made a difference!

 

[Misterg]

How do you think all this would affect the running of the engine, and the long term condition of the HT system ?

The 'leaving the leads loose' thing (and the button in the HT leads) is/was a dodge to get a more powerful spark by increasing the voltage needed to jump all the gaps.

IMHO: I wouldn't leave your setup as it is - may well work now, but the spark will probably start 'tracking' across the the coil insulator on the next damp day (or when it gets a little dirt on it) due to the higher voltage. Once it does this for any length of time, little carbon tracks develop that will short out the spark more often - only cure is a replacement coil.

 

[jack-daniels]

I recall that being done with a button, the wire wrapped through the holes to provide the gap.

YES! Your right, thinking about it, it probably was buttons!

 

[Nomad]

Most of my "retro" cars were Fords etc from 60s/70s, alomst all had Lucas coils with blade fittings bolted on top see photo, easy to fit the same connectors on your coil.

For the screw in HT connectors look at British bike suppliers, I've seen both long and short screw connectors on older magnetos etc.
The matching HT leads would have been copper cored.

Reliability and availability of parts are more important to me than originality so I normally swap out the complete ignition system (coil, HT leads & caps, plugs..) and fit modern - with either an integrated electronic ignition unit or an aftermarket electronic ignition kit.
* If you prefer originality ignore this suggestion

 

[Farside]

Reliability and availability of parts are more important to me than originality

Same here.
First thing I used to upgrade was the wheezy old dynamo and fit a Lucas alternator*.
Next thing was an electronic ignition system.
After that, halogen bulbs.

*Sometimes this included making it a neg-earth system.

I really , really don't understand the 'originality' freaks, who will revert changes to the crappy ancient parts.
I wonder if they'd be really happy with rubbish 50s brakes, too.

 

[Smallfry]

Same here.
First thing I used to upgrade was the wheezy old dynamo and fit a Lucas alternator*.
Next thing was an electronic ignition system.
After that, halogen bulbs.

*Sometimes this included making it a neg-earth system.

I really , really don't understand the 'originality' freaks, who will revert changes to the crappy ancient parts.
I wonder if they'd be really happy with rubbish 50s brakes, too.

Car has 50's brakes, and seem more than adequate to me, apart from the inherited poor adjustment, and the add on brake servo non return valve being installed the wrong way round. What I really dont like though, is the single line brakes.

 

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[Jack_K]

Solid core leads can cause issues with electronic ignition systems. Inductive core leads should be used but they obviously don't fit the Lucas screw HT terminals correctly but I've still done it.

I don't see how leaving the leads loose would improve anything, it reduces the energy available to the plug but does increase the voltage.

Make sure the distributor is in excellent condition (bushes, advance curve etc) otherwise you'll be constantly having problems. I just dealt with a worn out Lucas DKY2A distributor, all the shafts I could find were worn. I was getting up to 10 degrees different timing at the crank on one cylinder. Due to good two cylinder parts being unavailable, I had to modify a newer four cylinder reluctor type distributor.

Don't be tempted to chuck in a new distributor, most have random curves and will result in engine damage unless they are corrected.