HT leads

[steve b]

Can anyone recomend the leads from Formula power.
I need a set and have been looking around at a few like Magna core(expensive) Whats best?? For a RV8

steve

[DaveEFI]

Can anyone recomend the leads from Formula power.
I need a set and have been looking around at a few like Magna core(expensive) Whats best?? For a RV8

steve

Just use a decent silicone set with resistive core. Fancy core ones are snake oil.

[RoverP6B]

Hello Steve,

I fitted my first set of Megnecor leads in 1989. In 2007 when I had my 4.6 litre engine installed, I fitted my second set of Magnecor leads,..new engine so I wanted new leads.

The removed leads I keep as spares, and are as good as the new ones in terms of their appearance. No degredation of the rubber or corrosion of the metal terminals. They were used for 125,000 miles (201,200km).

I have never used silicon leads so I am not in a position to compare, so all I can say is that for me and my Rover, the Magnecor leads have been truly excellent.

Ron.

[ramon alban]

Hello Steve, this is very much an opinion AND anecdotal based subject. As it happens, due to having had a bad experience with expensive trash, I happen to agree with Dave's "Snake Oil" comment, but to put things into context have a read of this extract from my recent essay on the SD1 Efi ignition system!

Spark Plug Leads are the arteries of an ignition system providing all-important paths that allow the HT current to transfer safely and efficiently from the distributor cap to the spark plugs.

# Living in harsh environments, the importance of good quality leads cannot be over-stated having to cope with extremes of temperature, abrasion, contamination and vibration induced flexing.

# They must also safely insulate the HT energy whilst suppressing electromagnetic interference (EMI), created when a voltage passes through a wire.

# EMI is electrical noise or interference heard as a buzz through the radio but may also wreak havoc on other electronics such as the ECU of a fuel injection equipped car.

# Original equipment plug leads generally combat EMI by using a carbon core material that has a high resistance to the flow of the spark energy.

# Aftermarket vendors offer a variety of leads with lower resistance to maximize spark energy.

# If shopping for change, look for lower resistance plug leads but also for good EMI suppression.

# Another consideration is the terminal to wire crimp. Poor crimps can contribute to intermittent performance, a dead cylinder and other problems.

# Pay attention too, looking for quality plug lead boots needed to resist the extreme heat of exhaust manifolds.

I would add to the above that when our typical RV8's left the showroom they has a perfectly adequate and 100% reliable set of OEM ignition leads. Nobody complained and very few owners rushed off to fit aftermarket stuff. why would they?

Now, 25 or more years later, we may have the unnecessary desire to fit expensive aftermarket stuff when in reality all that is needed is to keep the ignition system in good order.

So! If you sympathise with the possibility of not spending very much money at all, have a gander at this easy to perform program.

Basic RV8 Ignition Maintenance Program

o For all the Low Tension components from the ignition switch right through to the coil, ensure that all the LT wiring is not corroded, broken, dodgy or otherwise failing.

o The suppressing condenser can break down under the back EMF from the coil and simply removing it to see if a fault condition disappears is an adequate test. Low cost replacement, only if appropriate.

o If fat sparks emerge from the king lead but not at the spark plugs its time to review the downstream components to see if they are dragging down, or failing to conduct, the Hi-Tension energy.

o Rotor arm - inspect for carbon tracking, clean with WD40, smear with a trace of silicon grease to prevent moisture ingress.

o Distibutor cap - inside and outside - inspect for carbon tracking, clean with WD40, smear with a trace of silicon grease to prevent moisture ingress. Wipe completely clean and shiny, especially between the turrets.

o Plug Leads and Hi-tension connectors - inspect for breaks and contact damage, clean with WD40, smear with a trace of silicon grease to prevent moisture ingress. Wipe completely clean and shiny.

o Spark Plugs - Check for recommended type, clean and gap to correct spec, inspect for insulator damage externally and whiskering/crud between central contact and body. Clean externally to a shine.

o The above four items are "zero cost" actions. Many owners replace them all never knowing which if any components may have been faulty.

o Check by swapping is an easy process before buying replacements.

o Looking for spark tracking on a dark night generally reveals faulty hi-tension parts

[DaveEFI]

'Silicone' refers to the outer insulation material. Basically, it withstands heat better than rubber or PVC, and pretty well all HT leads use it.

So it's the core or conductor material and design which varies. The first HT leads used copper. When the need to reduce EFI became necessary, these were supplemented with series resistors - often one at each end. Later leads incorporate this resistance in the core. First by carbon impregnated 'string' which had a relatively short life, and now more usually by conductive plastic.
Ignition systems are designed with these resistive leads in mind - indeed some like EDIS won't operate with copper core cable and ordinary spark plugs.

Of course many sellers will claim their 'special' cable performs better. And charge through the nose for it. Let them prove it in properly conducted trials before wasting your money.

One of these sellers also sells fuel 'catylists' Claimed to improve the octane rating of the petrol. And not so long ago, to also replace the lead in petrol and prevent valve seat recession on older cars.

It's possible these 'fancy' plug leads have a longer life. If so, where is the lifetime warranty?

[Will Reeve]

I've just bought a set from fast lane, yet to arrive, the spec. looks very similar to Magencor but 1/2 the price, and made in the UK!

In theory the spiral wound core leads should last longer than the carbon ones. I think there is hopefully better build quality on the more expensive wires, and they should look better as well!

http://www.max-boost.co.uk/max-boost/in ... 0Wires.htm

is a good read.

[steve b]

All very interesting thanks,I have to say never had problem before with standard leads but what I've had I've never missed. Ithink I'll do some more research.

steve

[DaveEFI]

I've just bought a set from fast lane, yet to arrive, the spec. looks very similar to Magencor but 1/2 the price, and made in the UK!

In theory the spiral wound core leads should last longer than the carbon ones. I think there is hopefully better build quality on the more expensive wires, and they should look better as well!

http://www.max-boost.co.uk/max-boost/in ... 0Wires.htm

is a good read.

Don't think the carbon ones are common now - it's usually conductive plastic.

[kiwicar]

For what it's worth the main reason for using a silicon rubber as the outer insulator is that it repels water, this maintains is't insulating properties when it rains, oh the bliss when I fitted my first set of silicone rubber plug leads to my mini and no linger had to cover the leads in WD40 when it rained (still had to cover the distributor in plastic).
Best regards
Mike

[DaveEFI]

For what it's worth the main reason for using a silicon rubber as the outer insulator is that it repels water, this maintains is't insulating properties when it rains, oh the bliss when I fitted my first set of silicone rubber plug leads to my mini and no linger had to cover the leads in WD40 when it rained (still had to cover the distributor in plastic).
Best regards
Mike

Never thought of that one - but I'd say the main reason to use silicone is the heat they can get to. For example, good quality soldering irons use silicone mains cable instead of PVC as it will resist being touched by the hot bit.

FWIW, the PVC insulation on the loom to the fuel injectors at the connectors on my RV8 was hard and cracked. Due to heat. As it was ok further down the loom.

[unstable load]

Back in my Mini days, I used a rubber glove from the local hardware with the fingers cut to push the leads through and a blob of silicone squeezed in to seal it all and then a zip tie around the dizzy for that end.

Made a world of difference to the Min and stopped a lot of roadside cursing.

[Will Reeve]

Received my leads today. Very happy, seem well made and a nice colour Measured DC resistance with a multimeter to be:
Coil: 4k7
Shortest lead: 4k00
4k17
3k96
3k7
3k96
3k97
4k17
Longest 4k81

All pretty similar, interesting to see how these change after a few miles.

[JP.]

If you want lots of resistance...trie Magnecor KV 8.5 they indeed have 2.2 kOhm/feet which did suprise me.
You'll need a serious coil to conquer that.

MSD 8.5 Superconductor cables do only have 50 Ohm/feet resistance.

Next time Ill get myself some MSD Superconductors again.

[Will Reeve]

I think 4 to 7k is good, compared to the plug gap the resistance must be relatively small! Remember we only measure DC resistance, the spiral wires especially will have a fair amount of inductance.

I'd love to see a back to back dyno test on brand new wires...bet all differences would be within the experimental error of the dyno!

The Magnecor leads do look and feel very high quality. I compromised middle ground I hope!

[ChrisJC]

http://www.max-boost.co.uk/max-boost/in ... 0Wires.htm
is a good read.

A fair sprinkling of technobabble unfortunately, a bit light on hard facts.

Chris.