Plug extender alternative?

[wseed]

Update, the NKG V05E isn't a suitable alternative. They're both too small and also have a screw type terminal at the lead side.

I have a missfire which I think is the cause of some of the hesitation between 1k-2krpm while accelerating and an inability to cruse at anything below 2krpm

While looking at the issue I can see on at least a couple of the HT leads it's occasionally arcing from the top of the extender. On inspection at least 6 of my extenders have cracked tops presumably from heat see pic. Looking for these parts they appear hard to source or expensive (~£10 each) for a part prone to failing. Would something like these NGK Resistor Spark Plug Cap be an acceptable alternative?



I've already ordered some heat protective sleeves (slow international shipping) and was considering getting rid of the extenders altogether but would these help in the interim?

Edited by wseed on Friday 5th May 08:56

[wseed]

Thanks very much for the offer, message sent.

[wseed]

737 FLF said:

For what it's worth.

https://www.amazon.co.uk/NGK-Resistor-Spark-VD05F-...

Thanks for the link unfortunately that's not the same part they're for 10/12mm plugs with a screw thread. If anyone else is interested the part required is VB05E I've ordered a set and will have a try with and without. Hopefully the heat protection will fit over both the leads and the caps.

[wseed]

GR_TVR said:

I ditched my extenders and am currently trialling some socks.
I got a length of each of these, cut into 8 and put one inside the other before putting the lead through it. The leads are heat resistant ones, too, so will see how these go...!

https://www.amazon.co.uk/gp/product/B005DRLKOA/ref...

https://www.amazon.co.uk/gp/product/B005DQGJY2/ref...

Thanks for the links, they're good prices for the UK stock. I've ordered the made up double layer 25mm socks and also a 20mm cut to length version as a belt and braces approach.

[wseed]

wseed said:

...Would something like these NGK Resistor Spark Plug Cap be an acceptable alternative?...

I spoke to the company today and the tech support department was very knowledgeable and helpful he said the v05e part number on their site wasn't quite right (I assume he'll correct it at some point) he tested that they would fit my plugs as there was a discrepancy over the diameter of plug they would fit. He was also familiar with the original parts and the issue on the TVR.

Edited by wseed on Friday 5th May 09:01

[wseed]

Update, the NKG V05E isn't a suitable alternative. They're both too small and also have a screw type terminal at the lead side.

[wseed]

Thanks for all the feedback folks, I only updated the thread so no-one else bothered trying the NKG extenders.

QBee thanks again for the load of yours taking the old extenders off has sorted my misfire. Still a little hesitation at low down but much better idle.

[wseed]

Just to close this off. I've now sorted my shunting issue the cause being a combination of failed plug extenders (thanks for the loan QBee), new ignition amp and a replacement King lead. I've also replaced some more of the ignition system (coil, dizzy cap, rotor arm) and have a new set of leads to fit the weekend so I have a bunch of spares for any European trips.

[wseed]

It turns out the protective sleeves I bought from China are not the best so am looking at alternatives. Looking at one of the posts above of a short metallic sleeve would there be an issue using something like this?

It looks like cut down it would offer protection from the radiant heat but I'm wondering what implications there might be using a conductive material.

[wseed]

Thanks CoG I'd seen your previous post re these. I found that the socks got scorched where they where in contact with the headers. I think you run without cats and that your manifolds are possibly cooler than with them in .

It could of course be that the socks I bought are garbage. I've reverted to the set that Qbee kindly loaned me.

[wseed]

Thanks for the info Dave you are indeed correct the parts I got where cheap junk from China although the leads where not so cheap junk from a landrover dealer. All now ditched. I've now got a set of leads that have cured my miss fire and run well I just want to offer them protection.

Regarding the plug extenders I've found a source and just contemplating if it's worth spending £40 on a set or not. There's so much conflicting info some saying the resistance is needed for a standard petrol engine and some saying the opposite.