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MG MGB Technical - HT Leads - Good supplier

Hi All,
I know this has probably been asked a thousand times but I cannot find anything via 'Search'
I am looking for a decent set of HT leads ('70 CB roadster) I recently bought a set to replace No4 lead which had worn through and the set I got is rather cheap and nasty and does not seem a very secure fit either at dizzy or plug end so I want to replace them. Any thoughts on a decent supplier at reasonable cost? It has standard coil and dizzy etc so don't need anything fancy

TIA
Bernie
B Anderson

Does Halfords do any solid copper leads? They used to when I lived there. You will need the connectors etc and radio suppression if need be? Mike
J.M. Doust

I bought Halfords silicon cored 22 years ago for the roadster and from the MGOC 17 years ago for the V8. I did replace the roadster ones some years ago as the coil lead connector developed a weird coating that seemed to insulate it and I couldn't scrape through it, the leads themselves were still as good as new. The V8 leads have done getting on for 100k now and are still fine.
PaulH Solihull

Technically, what determines a 'Knackered' lead? The old graphited string for want of better words just stopped conducting is that right? What can go wrong with the silicon cored ones? Is it silicon in the core, or a metal? Sure copper ones can and ultimately do fracture. Some super conducting material would be the ultimate? Mike
J.M. Doust

I bought a set of silicon HT leads from Summit about 20 years ago and Mike said at the time the would last forever. I have since changed the king lead because it was the easist way to match the OE coil to the 45D4 dissi. Thats metal cored and was cut from an old set. It all works fine. The core material ssems to be a resistive silocone rubber based material in several filaments. You do need resistance in HT leads, it provides RF damping and prevents excessive currents when the arc stikes. It has no effect on firing, no arc no current so resistance doesnt matter. 5 to 10K ohms would be a usual value.
Stan Best

Carbon string start going high resistance from day one as the carbon dust migrates, until eventually it starts affecting the spark. But because it's gradual you probably put up with it for quite a while until it gets really bad. At the time I got my V8 silicone leads the MGOC were doing carbon string - at quite a bit more than silicone.
PaulH Solihull

Here:

http://www.gsparkplug.com

I got all the bits there and made my own set. Copper core wire too.

- Paul Barnes
Bensalem, PA., USA
P. Barnes

Thanks Paul, Forgive the 'being a bit thick' but I had not even considered making them up. So do you just crimp the connector(s) onto the un-stripped cable or is there a 'method' I guess you put insulators over then crimp then pull the cover over
B Anderson

Usually the connectors have tangs that pierce the insulation and go through to the conductor. If they don't then it has a severe impact on the HT performance, and may not run at all.
PaulH Solihull

Thanks Paul. So I probably need a decent crimp tool then?
B Anderson

Bernie
I made my own "set" with no tools except for a sharp blade and a screwdriver.
I purchased repro lucas 90 degree plugsockets and a piece of copper cored HT lead from a local auto electrician.

The sockets have a built in tapered screw so you just screw this onto the lead.
The other end slides into the hole on the dist cap and you tighten the screw on the inside - it has a sharp pointed end that pierces the insulation and (hopefully) makes contact with the copper core

The biggest problem is trying to make sure you get the lead lengths right if you don't have old ones to guide you - I over compensated and my leads are too long - but at least I can easily shorten them!
John
John Minchin

This thread was discussed between 14/05/2012 and 29/05/2012

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