Plug Leads, What's the shrouded bit for ?

[steve-v8s]

The plug leads on My 98 Griff have a shrouded arrangement at the end comprising a socket that fits over the plug and a plug that connects to the plug lead. I guess these are resistive suppressors intended to take the edge of the current spike in the plug lead and reduce radio interference. Does anybody know if they serve any other useful purpose ? One of mine has fallen apart resulting in a misfire, removing it and connecting the lead directly to the plug and the engine seems fine. I propose to remove them all. What do you think ?

[shpub]

They also help stop the lead going onto the exhaust and melting. They also provides some protection against heat.

Steve
www.tvrbooks.co.uk

[Guillotine]

the resistor also affects the spark shape and duration so its best to run them.

mines been without the resistive ones for 2 years. using non resistive and have no probs.

[DustyC]

I do believe they are a refered to as King Prawns.

Have a look again and you'll see what I mean!

[griff430]

I don't think they are too expensive to replace (as long as you're only replacing one or two!!) Apparently, they are a standard GM part, and so should be fairly easy to get hold of.

[deeen]

ACT non-resistive are cheaper than std GM resistive, apparantly

[Apache]

I thought they were there to burn your hand

[steve-v8s]

I would think that the resistor would have little effect on the initial spark, but would serve to reduce it’s length. When the field in the coil collapses the spark gap is a massively high impedance compared to the resistor so the resistor has no effect. Once the spark starts and the impedance across the gap becomes close to zero the resistor then becomes important and will dissipate a fair proportion of the energy. As the spark will continue whilst there is sufficient current flowing to keep the gas ionised, and the main limiting factor will be the resistor. So the question is does correct combustion require a long spark or a short one. Once the fuel is ignited I shouldn’t think it matters. Possibly the plugs and coil will be less stressed if the current is limited, and certainly an AM radio will work better.

An interesting topic, any experts out there ?

[RichB]

deeen said:

ACT non-resistive are cheaper than std GM resistive, apparantly

Are these teh magnacore ones? Rich...