Author Topic: Ignition System - HT Side Overview  (Read 2018 times)


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Ignition System - HT Side Overview
« on: August 18, 2012, 08:34:58 PM »
Ignition System:

The original Lucas Rita ignition system employs Type 17M6 ignition coils (6V coils, wired in series for the Hesketh's 12V system).  The coils may have stood the test of time, but, if you still have the original HT leads fitted it’s highly likely that they’re starting to suffer insulation breakdown and conductor/contact corrosion.  Fortunately, the 17M6 coils accept “standard” car-type ignition leads.  This makes their replacement/upgrade an absolute doddle:

I opted to go for fully suppressed, 8 mm silicon leads and (after a bit of web-scouring) I sourced a pair of “Lumenition” performance leads, via Autocar Electrical Equipment Co. Ltd. () Other manufactures and suppliers are, of course available, but I wanted to buy and support British.

No matter where you source your leads, the dimensions requirements will be the same:

Front Cyl:  18 inches (460mm) – The Lumenition Part No is 18P8.
Rear Cyl: 24 inches (610mm) – The Lumenition Part No is 24P8.

When buying: Please ensure that you’re getting “plug” leads and not coil – distributor, or “king” leads.  Only the former have plug caps fitted.  Shop Around… Prices for very similar products can vary dramatically.

When fitting:  Now is an ideal time to fit a new pair of plugs (NGK DR8EA, or DR8EIX if you absolutely MUST have the latest Iridium “sparklers.”

DON’T unscrew the terminal nut from the end of the plug.  Instead, nip it up tightly with a pair of pliers.  Your new, car-type, leads need the terminal nut in place to snap the plug cap onto.

DO route the ignition leads from coil to plug, taking care to avoid positioning the lead against sharp edges or trapping it between components.  The Front cyl is easy , but the rear is a tad awkward (to say the least!!).

Hope this helps.  Please feel free to post up any additional tips or sources for your Hesketh's HT parts.

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