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HT Leads for Wasted Spark Coil Pack
Replicar328 - 5/7/22 at 02:23 PM

I'm looking at the idea of replacing the distributor (which is shot) on a Triumph Herald 13/60 engine and thought I'd have a go at using a wasted spark coil pack with built in driver. I bought a coil pack for less than £20 but the required HT leads are clearly different from those used with a distributor, having a raised peg in the middle of the holes, where the distributor has just a conductive cylinder into which the HT leads fit and make contact.

Looking to buy "coil pack HT leads" I'm finding they can be had for around twice the price of the coil pack and I'm still not sure if they wil be okay. I'd very much appreciate tapping into expertise on this forum as to what HT leads to use and where to get them!

Also, do I need different plugs?

Cheers
Adrian


myke pocock - 11/7/22 at 08:08 PM

Have you thought of going to a scrappy first to source some then if you want new you will know what fits. I converted my Skoda Estelle trials car to Ford Edis, bought a lead set and found one was too short. Luckily a neighbour had a longer one hence the scrappy idea and you can check the length also.


Replicar328 - 11/7/22 at 08:17 PM

Good idea Myke, might just do that. Just looking at them would help - and I can arrange the position of the coilpack to accommodate fairly short leads


scudderfish - 12/7/22 at 10:21 AM

You can make your own for not a lot of money, the ends just crimp on. What make is the coilpack?


indykid - 12/7/22 at 11:05 AM

If it's a generic one like this it suggests they're 'M4' terminations which are apparently Ford Zetec style.

As Scudderfish says, you might be better making your own because most off the shelf leads will have long boots on the plug end for fitting into DOHC heads


Replicar328 - 12/7/22 at 12:07 PM

Thanks gentlemen. It's a Standard Lemark CP011 Lemark Coil bought on Amazon and it looks precisely like the the one mentioned by indykid. The recommended leads are about twice the price and I do quite like the idea of making my own - where would I source the ends that go into the coilpack and would I need the rather complicated connectors on the spark plug end? Maybe the Amazon price of £37.19 is not so bad after all - at least I can reasonably expect them to work!

Once I've got this sorted the next step is to take the position and speed of rotation from a crank trigger wheel plus a MAP sensor for vacuum advance. Not sure if I can figure out how to do this without a processor....


indykid - 12/7/22 at 12:43 PM

I have no connection and no experience, but Mr Retro Leads seems to have the bits you need or does custom built lead sets

Also the green sparkplug company

I just googled 'm4 ht lead'


Replicar328 - 12/7/22 at 01:32 PM

Thanks inddykid, I'll follow up on both these leads - no pun intended


Sanzomat - 13/7/22 at 06:59 AM

I used that same coil pack on my R1 locost when converting to Speeduino. For HT leads I had a Mk1 Focus (zetec) coil pack and leads in the shed and the Focus leads fitted the coil pack perfectly. The plug ends even fitted with a bit of fettling and addition of the nipples on the spark plugs as bike plugs just have the threaded part. So, if they are the right kind of length you could get Focus HT leads? They are quite short though but maybe mount the coil pack close enough and extend the LT wiring?

[Edited on 13/7/22 by Sanzomat]


Replicar328 - 13/7/22 at 09:08 AM

Thanks Sanzomat, good tip, I searched ebay and there a number of Mk1 Focus lead sets advertised at reasonable prices. I actually plumped for a set described as being for a 2005 Ford Fiesta 1.25 because the photo showed the kind of coil pack connector I need so I'm pretty sure they will work - just £12, postage free.

Annoying thing is, the search also led me to coilpacks for less money than I paid!!