Plug leads..........

[Hedgehopper]

I am about to order a new set of plug leads. The ones I have at the moment (original Lucas suppressed leads) have angled caps at the plug end allowing the leads to come upwards and over the rocker covers. All the pics. of replacement leads have straight ends causing the leads to face outwards away from the engine.

Anyone know who sells the angled leads..... and does it matter anyway?

Thanks

[gavgavgav]

(I'm still running the extension caps) I've replaced with a set of straight leads, they just point the leads towards the body, plenty of room to curve back to the right direction.

[FlipFlopGriff]

Hedgehopper said:

I am about to order a new set of plug leads. The ones I have at the moment (original Lucas suppressed leads) have angled caps at the plug end allowing the leads to come upwards and over the rocker covers. All the pics. of replacement leads have straight ends causing the leads to face outwards away from the engine.

Anyone know who sells the angled leads..... and does it matter anyway?

Thanks

Tim at ACT.
FFG

[Hedgehopper]

Thanks for the useful replies (two within 12 minutes!), the help from this forum never ceases to amaze me.

[Aaron C. Reskew]

The metal extensions the ignition leads click onto are absolutely necessary to prevent the lead from burning, as they are in very close proximity to the exhaust manifolds.
The standard TVR ones with the Lucas leads are resistive. Aftermarket ones (usually fitted with upgraded ignition leads) are not resistive.
I can supply a set of Magnecor 8mm ignition leads complete with the angled extensions for £135 all in including postage.
They come with a 10 year guarantee.

Ian

[blitzracing]

Please don’t go down the "resistive" is bad, non resistive is good route, there is a whole lot more to HT leads than this. You need to control the current through the HT lead when the spark occurs to prevent big spikes in the coil secondary and primary to prevent radio interference and higher voltage spikes on the ignition primary. Resistance also controls the spark duration, as if the leads are very low resistance, the spark duration is much shorter (albeit hotter) but you don’t need this on a lazy V8 that’s not running very high compression, or LPG / Nitro etc, so there is nothing whatsoever to be gained by buying over priced Magnecores. Technically the Magnecores use an inductive coil of wire around cable that resists the rapidly changing HT voltages, and provides a level of reactive resistance to control the spark but without dissipating so much power in the plug lead itself, so they have their place in environments where the combustion chamber conditions are likely to prevent or extinguish the spark. This occurs in conditions where the voltage required to get the spark to ignite in the first place is prevented by either the fuel type used or the air density at the point of ignition, but the old RV8 system has enough HT "headroom" to fire the mixture even at 6000 rpm plus with decent stock leads.

[FlipFlopGriff]

The Lucas leads were starting to break down afetr about 4000 miles on the 500 and it was pain to keep replacing them. Magnecores been on 5 years or more now with no issues, in a daily use car.
FFG

[Chris99]

I had Magnacors fitted about 1,000 miles ago as part of an overhaul of the HT system (coil, dizzy cap & rotor).

Maybe overkill for the rover V8 but it cured a missfire and they look good

[blitzracing]

FlipFlopGriff said:

The Lucas leads were starting to break down afetr about 4000 miles on the 500 and it was pain to keep replacing them. Magnecores been on 5 years or more now with no issues, in a daily use car.
FFG

I do quantify my statement with "decent" standard leads.

[Aaron C. Reskew]

blitzracing said:

Please don’t go down the "resistive" is bad, non resistive is good route, there is a whole lot more to HT leads than this. You need to control the current through the HT lead when the spark occurs to prevent big spikes in the coil secondary and primary to prevent radio interference and higher voltage spikes on the ignition primary. Resistance also controls the spark duration, as if the leads are very low resistance, the spark duration is much shorter (albeit hotter) but you don’t need this on a lazy V8 that’s not running very high compression, or LPG / Nitro etc, so there is nothing whatsoever to be gained by buying over priced Magnecores. Technically the Magnecores use an inductive coil of wire around cable that resists the rapidly changing HT voltages, and provides a level of reactive resistance to control the spark but without dissipating so much power in the plug lead itself, so they have their place in environments where the combustion chamber conditions are likely to prevent or extinguish the spark. This occurs in conditions where the voltage required to get the spark to ignite in the first place is prevented by either the fuel type used or the air density at the point of ignition, but the old RV8 system has enough HT "headroom" to fire the mixture even at 6000 rpm plus with decent stock leads.

I think you have misinterpreted my post. I am not comparing one to the other in a "performance" sense i am merely pointing out that the OE fitted shrouds are resistive and the after market ones usually fitted in conjunction with Magnecor or similar are not. As the resistance is within the cable as you rightly say.

I suppose what i was getting at was, do not use the OE shrouds with Magnecor or similar leads as you don't need the extra resistance afforded by the OE shrouds.
A non resistive shroud is far cheaper than a resistive one as well.

The only advantage i can think of in using Magnecor leads is their "survivability" in the extreme environment of the TVR engine bay!

[MPoxon]

I purchased my Magnecors and plug lead extenders from ACT about a year ago.... excellent service as always from Tim

I know Rover V8 Guru Mark Adams did some work testing various leads and an ignition analyser some time ago and he recommends them which is good enough for me.

...... plus they look good

[Johno]

Moroso all the way.

Cheaper, better fit at spark end, choice of colours for the fashion conscious, available in 8 or 10mm, different ends for those who want something different but the 135 degree fits perfectly up against the rocker covers, make them to your own length so no excess or awkward routing, ideal as you get nice neat plug leads that leave the caps vertically, not all loose over the top of the manifolds requiring even more clips etc to try and stop them moving . .

Did I mention they were a lot cheaper and have outlasted the 3 sets of Magnecors I've had on different cars (you'd think I'd learn my lesson, but knowledge has to be acquired) . . Magnecors for me and a number of friends TVR's have only resulted in another bill to replace them as in my experience they break down regularly and Magnecor have no interest in actually honouring their warranty in one friends experience either, your lead doesn't work, gets back - you must have used it wrong so on and so on ad nauseum . . ...

Big name brands aren't always as good as they're advertising but they're easier to sell for more money than they're actually worth making them and the vendor more money.

Edited to add . . . http://www.realsteel.co.uk/section9.pdf Page 4 'Blue Max Spiral Leads'

Edited by Johno on Wednesday 6th July 16:02

[blitzracing]

[quote=MPoxon]I purchased my Magnecors and plug lead extenders from ACT about a year ago.... excellent service as always from Tim

I know Rover V8 Guru Mark Adams did some work testing various leads and an ignition analyser some time ago and he recommends them which is good enough for me.

...... plus they look good

I asked Mark why he liked them, and he said they worked really well in the Range Rover world where both water and the use of LPG is more of an issue when it comes to sparks, plus they where reliable as far as he was concerned.

[JamesK]

Wait, is that a recommendation or not?

I'm about to have a service and replace my plugs/leads. I'd like to pimp my engine and magnecor's are on my list. Without wishing to stray off topic - does anyone have a strong opinion on what NGK plug type goes best with which tihckness of lead? I know "7" is the usual plug recommendation but for a highly tuned BV?

[blitzracing]

Using "street" Magnacors is OK if you want to simply spend the money over OEM leads and you like the look, but bear in mind that a set of Bosch leads is around £35,(when I last looked anyway) and dont expect any power gains. Also consider there can be an issue with Magnecors due to the lack of path resistance that can make the rev counter a bit glitchy due to the higher voltages generated in the coil primary when the spark resistance path is low. This can be overcome with resistive shrouds or plugs to increase the overall resistance between coil and plug tip to slow the discharge rate. You dont need "race" type leads or extra thick silicone for the RV8 setup. Check the Magnecor site, its pretty fair with its claims if you want to dig through it and want to spend the extra. Its some of the retailers who can get a bit carried away with claims about what they can do!

[SILICONEKID340HP]

Blitz what do you recommend with ford coil packs.I have standard NGK plugs not surppressed, some old but tested leads (far to long) which came with the Megasquirt so dont know what they are, The plug extenders have 5k stamped on them,are they surppressed.

Edited by SILICONEKID340HP on Wednesday 6th July 20:56

[paulathome]

Daz, yes they will be resistive leads 5k equals 5000 ohms. I would
Stick with those on a megasquirt ECU to stop radio interference and
Possible ECU resets.
Paul

[SILICONEKID340HP]

paulathome said:

Daz, yes they will be resistive leads 5k equals 5000 ohms. I would
Stick with those on a megasquirt ECU to stop radio interference and
Possible ECU resets.
Paul

Thanks for that ,so i can keep the standard plugs .i would like to make my own leads up , would be impossible to buy them off the shelve.What type of lead would i need and where can i purchase the two different type ends , clip on type for the coil packs and the other for the plug extenders..

.

[blitzracing]

JamesK said:

Wait, is that a recommendation or not?

I'm about to have a service and replace my plugs/leads. I'd like to pimp my engine and magnecor's are on my list. Without wishing to stray off topic - does anyone have a strong opinion on what NGK plug type goes best with which tihckness of lead? I know "7" is the usual plug recommendation but for a highly tuned BV?

The lead thickness is purely a factor to consider dependent of the peak voltages experianced by the cable. On engines running high turbo boost pressure, nitro, lpg etc the HT voltages can raise to a higher level before the spark ignites, which can lead to breakdown of the leads insulation over a period, so a thicker lead is a good idea. This does not apply to a TVR engine however tuned, as you never reach a the types of conditions listed above, so you dont need the "race" leads. The plug type has nothing to do with the lead thickness. Stick with the same plugs, and only change them if the burn colour is wrong (ie black ), or if you have a glitchy rev counter with magnecors, you could fit the resistive type plug of the same value.

[davetherave1970]

blitzracing said:

or if you have a glitchy rev counter with magnecors, you could fit the resistive type plug of the same value.

This is what I have
Service and MOT next week so i'll ask for this then!