Question about ignition wires

[Yakov]

Does it make a difference as to what kind of ignition wires to use for the plugs and coil to distributor?
I ask this because my original wires and the replacements I got from HaflingerTechnik have next to zero resistance, while modern ignition wires have comparatively high resistance.
When I ran with modern wires, I had some trouble with the ignition, and I was always changing plugs. Then again, I never tried brand new wires, just ones I had lying around. So maybe my experience isn't conclusive.

What sort of plug wires do you guys use? Theoretically, should the resistance of the wires make any difference?

[AustHaflinger]

I must admit that I thought that with the exception of hi performance engines all basic ignition and HT leads were pretty much the same far as performance goes. For sure construction varies - older tend to be copper and new seem to be carbon but in my experience all work OK.

My leads for my V12 Jag are generic leads from the auto shop as are my V8 Rover engine. When I got my Haffie it had a hi tech electronic ignition with wasted spark coil pack and modern leads. I then went to standard points and coil but kept the same ignition leads and had no issue - have now a Petronix and still running the same leads.

So - in my view any modern lead (will be silicon insulated carbon core (suppressed) bought at any old auto store should suffice. My old 57 landrovers originally had copper cored leads and they work fine with modern carbon cored leads.

Not sure but I think modern leads have higher resistance as they are noise suppression leads and it is the resistance that provides the suppression.

Just my thoughts.

Garry

[heinkeljb]

Old style solid copper leads work well but you need a resistance suppression cap to make the connection to the plug, unless you want to annoy al those around you with the whine you get on your radio which varies with engine speed!

New HT lead, are as Gary has said, carbon cored. The problem with these is that like the old copper cored versions, they can break internally. Carbon cored HT leads are already Radio suppressed so you don't need special HT caps to go on the spark plugs. I can still buy copper cored wire here in the UK, but I don't know if you can get it where you are. A good motor bike shop specialising in old bike will probably have copper cored HT wire by the metre.

Brand new HT leads of which ever sort should work - Have you tried a different HT Coil? They do fail and most fail by producing a miss-fire when HOT due to the internal insulation breaking down. Gary purchased one not that long ago. I can't remember if he listed a suitable replacement there or not.

I purchased a pair of modern HT leads for Lurch when I found one of the originals had been eaten down to the core by some furry animal. It would start and tick over, but the moment you increased the revs, it would miss-fire (arcing from the bare section). Replaced and not further problems in that department.

John

[Bigdougal]

I just bought a set for a VW Beetle. They work great and being a 4 cylinder you get a spare set. Cost next to nothing.

[Yakov]

Alright. So I guess the suppressed wires I tried must have been bad. What do you guys mean by the suppression cap? Is that the rubber boot? Did the Haflinger originally come with suppression caps?

I like the look of the stock ignition wire ends with their orange boots at the end and they seem to work, so I'll stick with them.
I was worried that the old original coil that I'm running with somehow couldn't make a good spark through a suppressed wire, but I guess it doesn't work that way.

[heinkeljb]

Suppression cap = the hard plastic cap that actually clips on the end of the spark plug.

You get ones which have a resistor in them and a metal screw which is designed to screw down the centre of a solid copper wire HT lead to make the electrical connection.

Modern Carbon cored HT cable have a moulded on HT cap to plug on the spark plug.

1950's / 1960's would originally have been copper cored, later 1960's / 1970's might have had carbon cored ones as that was when carbon cored HT lead started to become available.

It is possible you current HT coil is not producing a high enough voltage to make a "good" spark in the cylinders when subjected to compression of the gasses in there.

John

[AustHaflinger]

Most old cars did not have suppression caps - they just ran wire leads noting that moist cars did not have car radios at the time. My two 57 landrovers never had them. Later when AM radios became more common and before carbon suppression leads were standard some sort of suppression device became available aftermarket. Here is Aust we tended not to use caps but had a suppressor that required the lead to be cut and each cut end screwed in the suppressor which was about 2" long and about twice the diameter of the lead. But as John indicated you could also buy caps that screwed into the end of the lead but they were not popular here as they were problematic.

I think you have either suspect leads and the first thing would be to replace them - just buy ones of the right length from your local autoparts retailer. Though, like John as indicated there could be other issues to check - most can be tested like points and coil but condensers can cause all sorts of issue and are almost impossible to check but are cheap enough to replace as a matter of course.

Get new leads and see how you go.

Garry