SPARK INTENSIFIERS ????

[lambrettalad]

Hi this is a new one on me "The Norton ignition converter" does any one know what they were or are and did they work?

bumph says "Gives better starting ,running and economy ...............?????"

[dalebrignall]

if its a king lead with a plastic cottenreel thing in the middle saying it is a multispark device dont bother its full of ballbearings and washers and will burn out your ignition system .

[autolycus]

"Burning out" an ignition system is an interesting concept. The total energy available per cylinder firing is limited by the coil, the condenser, and (sometimes) by the time available to "recharge" the coil, so I'm not sure what would burn out, or why.

I mentioned the auxiliary spark gap business in another thread today, having watched the effect on a 6-cylinder engine yesterday. I'd got the engine hooked up to a Crypton tuner (my new toy) and identified one cylinder as not pulling its weight. Disconnecting the HT lead showed only about half the rpm drop that I was getting with the other cylinders, but when I held the plug cap about a tenth of an inch away from its fully clipped-on position, the engine revs picked up, only to drop again when the connection was fully made. I concluded that the extra spark gap was helping that cylinder to fire properly. I know there's always an extra gap in that the HT current jumps from the rotor arm to the distributor contact, but for whatever reason, it improved matters. This plug turned out to be carbon-fouled from a period of idling with a very rich mixture.

So if the "Norton Intensifier" is essentially an extra spark gap, it may help in some circumstances. Perhaps one day I'll try to have a look at HT waveforms on the Crypton to see what's really happening, but for the moment I'd better keep draining the swamp, i.e. getting this wretched car running on 6 every time.

Kevin

[bmcecosse]

Yes a gap is a way of clearing a fouled plug......obviously the Norton is a great device - everyone should have one......

[RobThomas]

From Morris 8 days...if you get a shirt button, cut your ignition lead, cut back the rubber surrounding the copper, install the wires in opposing thread holes in the shirt button...hey Presto...you have a spark gap intensifier.

Worked for me on a plug in an oily cylinder. It would somehow make the plug fire even though it was getting masses of oil on it. Got me home!

[bmcecosse]

Great tip!

[autolycus]

So Rob knows it works; Roy knows it works; I know it works; the world and his brother know it works: but how does it work? Why does the spark jump a 25 thou gap when previously the energy was being dissipated in the layer of partly-conducting fine carbon?

Kevin

[bmcecosse]

Just because it has to 'build up' before it can leap the first gap -and then it immediately leaps across the second gap. If no first gap - the HT builds up slowly and leaks away across the contamination on the plug. I have cleaned up 'oiled' plugs just by holding the cap a few mm away from the spark plug for 20/30 seconds. But I don't think it will make any difference to a good running engine..........

[autolycus]

But why is it the extra gap that makes the difference? There's already the significant gap between the rotor arm and the "contact" in the distributor. Come to think of it, I'm not really sure how serial spark gaps work at all, because the intermediate cable, in the simple case the HT lead between distributor cap and sparking plug, is neither at ground potential, to give a pd between rotor and "contact", nor at HT potential, until one spark gap or the other is ionised and conducting.

Since most of the messageboard members seems to be students, aren't any of them reading physics? They're certainly not reading English or Classics.

Kevin

[bmcecosse]

" They're certainly not reading English or Classics. " Hahahahahaha - surely ' There not reeding....' is the speling upseting you Kevin??

You are right - there is already a gap - I can only the offer the explanation above - nothing else makes any sense! It does work on fouled plugs But I don't see any advantage with good plugs.

[RobThomas]

The ignition will only dump the energy down to the sparkplug once there is enough 'juice' to jump the biggest gap. Small plug gap (25,000 volts across 25 thou) will now have to wait for the big gap (40,000 volts over 35 thou) to be jumped before the spark will flow.
If you have copper leads, plain caps and non-resistive plugs you will fire the spark at too low an energy level and thus get weak sparks. Ideally you need 5000 ohms between the dissy cap and the tip of the plug to get a fat, juicy spark. NGK plugs with an 'R' (eg BPR6ES) have 5000 built in, their caps are marked 5000 ohms and standard carbon plug leads are about 5000 ohms per foot.


If that doesn't make sense, imagine flushing the bog before it has filled the cistern. You won't get more than a little swish of water until enough water gets punched into the syphon mechanism. An 'extra gap' in this anology would be a system that prevented a flush motion from beginning until 50 gallons of water had built up in the cistern and the handle had already been pulled, even if it had been pulled a few minutes before. Then you'd get a 50 gallon flush, enough to wash away even the BIGGEST....errrr.

[bmcecosse]

Good explanation there........ I think R plugs with carbon leads can lead to weak sparks too. Only ever come across it with the NGK plugs - mates MGB just would not start..... Put in an old set of Champs from my bag - started right away.

[RobThomas]

Problem seems to be when you have a need for 40,000 volts to fire across an oily plug and the coil/condenser can only charge up to 35,000 volts, if you see what I mean. The ignition will fire the spark as soon as it has enough EMF generated to cross the biggest gap but at high rpm on a V8 engine you might not get enough charging-up of the condenser to fire it and hence they fit V8s with dual point distributors, high energy coils and electronic ignition etc.

With R leads and carbon wires you might perhaps get so much resistance that you lose amps (V=IxR)? Dunno.

I tend to think of the 5000 ohms as being like the new type Ketchup bottle with that little 'bum-hole' pourer nozzle on it. It waits until you've built up enough force (ie squeeze strength or voltage) to trigger the pulse with enough ooomph to fire the (spark or sauce) the required distance. Not enough force and it won't 'fire', not enough strength in the sphincter and it will fire off at just a dribble.

[RobThomas]

Wow. 'Bum-hole' gets through the obscenity filtering!

[MarkyB]

We need an unpleasant metaphor filter.

[Thaya]

Hi all,

Recently experienced the same symptoms explained here in my moggy engine cylinder number 4. Upon removing the plug, it didn;t seem "oil fouled", but was wet. Other 3 plugs were slightly sooty (but dry), which I'm thinking of fixing by making the mixture a flat or two leaner.

1. On cylinder 4, when I hold the HT about 1/2 an inch away from spark plug top, the idle speed revs up slightly and engine runs smoothly. Completely removing the lead or affixing it to the plug lowers the rev down to the inital level. When held slightly away and I move the HT lead towards the plug top it still throws sparks.

2. I have champion N9YC on all four cylinders. Next I connected timing light to every HT lead and on cylinder 4 I have a very irregular flashes with dead periods upto couple of seconds.

3. Holding a tissue paper covering the exhaust shows irregular suction coinciding with a jerk (momentary lowering) in engine RPM

4. There was a light rattle at accelerated RPMS when going in second gear

Removed plug attached to cylinder 4 and replaced with a NGK BP6ES that seemed to have a slightly larger gap and was clean.

1. Engine runs very smooth and noticeable power while driving.

2. Timing light flashes more regular

3. Very occasional suction at the exhaust

4. Rattle vanished

5. Exhaust now drips water during idle.


Planning to run for a while and see what happens. Could it be worn piston rings? / valves? in cylinder 4.
No black smoke at the exhaust though.

[MarkyB]

Sounds like a duff plug which you have diagnosed and cured.
Water from the exhaust is normal.
Black smoke is from rich mixture, blue from buring oil.

[Thaya]

Thanks Mark.

I'm sure I never saw blue smoke. Thats a big relief. Will run for a while and see. Didn't get a chance to do a reasonable run at cruising speed. Only short trips which I'm sure wouldn't have helped cure the wet plug.

Previously I tuned the engine with Gunson Colortune and according to my percpetion flame was dark blue during idle and yellowish only during fast acceleration, which I thought was correct.

Btw, Happy New Year to everyone!

[bmcecosse]

Check the valve gaps - but as above - probably oiled up from worn bore/piston rings.

[Thaya]

Yep. Will make it a point to check valve gaps and status of bore / piston.

Have deferred all engine related repairs to be done together.

The plug is not oil fouled, it just happens to be super wet. The engine oil is 20W50 Castrol Mineral Oil

When it fires well, there is noticeable power increase and ability to climb the same slopes in higher gears that was not possible earlier. Unfortunately I don't own the gadget to do a compression test and see. My perception of increased performance had been relative and I didn't have an absolute reference as to what the performance of a standard 948CC A series should be until recently I drove the Morris of my friend and realized mine was not up to the mark.

Thanks for all the suggestions.