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MG MGB Technical - New leads set

Hi, I want to renew my spark plugs and leads, can you recomend the best ones to get for my 1967 MGBGT, I want to get good quality ones, there are so many on the market.

Cheers Jack.
Jack New Forest

Halfords silicone-cored are all you need. I've never had a silicone-cored lead fail (I did have a problem with one connector) in getting on for 200k on three cars. Definitely do not get the original carbon string type, they go high-resistance and in any case are more expensive.
PaulH Solihull

Thanks Paul good info.

Cheers Jack
Jack New Forest

Paul,
Is there a part number for these leads. I tried the Halfords website and they don't list for MGB.
Steve Church

Does your '67 still have the side entry cap? If so, you'll have to go with solid copper wire cored ignition cables, with resistor caps mounted on the sparkplugs. RAY
rjm RAY

Yes I wondered about solid copper core. My old mini returned a good jump in performance, once I changed from the old graphited string to copper leads. But, stands to reason the old leads were past their date! I supoose the drawback of solid copper is their interference with the radio? Did they not need suppression? Mike
J.M. Doust

Jack-
Copper was the prime choice to use as an ignition conductor in High Tension (HT) leads (Spark plug leads) during the infancy years of motoring. Copper ignition wires were durable and would normally last the life of the car. It also provides almost no resistance to the flow of electricity to ignite the spark plugs and had the advantage of being inexpensive to manufacture. However, these conductors emit too much Radio Frequency Interference that causes interference with other electronic devices. In order to suppress this interference, they require the use of resistor-type spark plugs.

Magneto suppressive type High Tension (HT) leads (Spark plug leads) have a tensile core like fiberglass, usually carbon string or silicone, with a small-diameter wire, usually of nickel alloy, that is coiled around it from end to end. The electromagnetic field generated by current moving along a conductor generates and radiates Radio Frequency Interference, which interferes with communications equipment. This resistance wire is an inexpensive way to reduce this interference. In the magneto suppressive type, the electromagnetic fields around the wound wire interfere with each other, stopping the Radio Frequency Interference, without introducing as much resistance as found in the resistor type of High Tension (HT) leads (Spark plug leads). Since they have actual wire, and are in effect a very long spring, they are more robust than the resistor types. Many high-end manufacturers produce them, usually marketing them as their “best”.

Yet another item is currently being manufactured and marketed as being in the “best” category. pertronix has taken their 8mm High Tension (HT) lead (Spark plug lead), which is designed to meet the demands of high performance engines, and now offer it with exactly the same features in 7mm flat black color, making it possible to fit state-of-the-art High Tension (HT) leads (Spark plug leads) into the Lucas distributor cap. It has two current paths for reliability and redundancy. Its primary path consists of spiral wound stainless steel alloy, while its secondary path consists of a carbon impregnated fiberglass center core. It has a low 500 Ohm-per-foot resistance. It also has silicone jackets to resist high temperatures, moisture, oil and chemicals, and an EPDM (Ethylene Propylene Diene Monomer) rubber inner insulation for superior heat resistance and prevention of arcing and voltage leaks. Fiberglass reinforcing braid is used for added strength and flexibility.
Stephen Strange

Very informative chaps and extra thanks to Stephen for the great info, I'm old school and my 67 mgbgt does not have radio fitted, so no problem there.

Jack.
Jack New Forest

This thread was discussed between 06/02/2012 and 07/02/2012

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