Plug gaps with Luminition ignition system GT6 Mk3

[Taggart65]

Hi all , was taking to a guy at a meet last week and he mentioned about using a different plug gap if electronic ignition had been fitted , have done a search of the net and not come up with much on the subject .

The mechanic that fitted my Luminition set up didn't change the gaps on the plugs though 

Does anyone have any knowledge on this please ?

[johny]

Best to speak to Lumenition who might have actually done some testing because otherwise youll probably get lots of different opinions😂

[Pete Lewis]

come on lets start the contention    

as you are only changing the dizzy switching and not changing the  HT coil or the spark plugs  leave them as the manual states 

Pete

 

[Colin Lindsay]

I'll agree with Pete; if you were upgrading the actual spark you could change the gap, but as you're only changing the interval or accuracy of the spark, leave it as is.

[johny]

Ah but you might be breaking the coil current flow more abruptly and as we all know the faster the magnetic field collapses the bigger the voltage produced (I think)...

[johny]

The thing is though, if youre already successfully igniting your mixture it doesnt matter how much longer or fatter your spark is it cant do any more igniting can it? The explosion cant go out and need reigniting! However fitting a second sparkplug to each chamber might make more sense👍

[RedRooster]

Best ditch the optic luminiation before it ditches you, I've had 2 fail and would never use their products again. 

RR

[Taggart65]

2 hours ago, Pete Lewis said:

come on lets start the contention    

as you are only changing the dizzy switching and not changing the  HT coil or the spark plugs  leave them as the manual states 

Pete

 

Coil was changed as well , my knowledge of these things is pretty much zero ! 

[johny]

To be honest I think igniting the mixture in our cars isnt a problem. It becomes much more difficult in lean burn, modern economical engines which is where high voltage, big spark systems are needed...

[Pete Lewis]

so what coil is fitted   does it have a make /model  etc     more clues helps us

Pete

[Peter Truman]

Also just for clarity is the Lumination the optic type or their Magnetronic unit

I’ve also had two Optics fail but had their Magnetronic fitted to the Sprint and all was good.

[Taggart65]

It's the Optronic system that's been fitted and the new coil is a Intermotor part number 11040 , the guy that fitted the set up is a very experienced mechanic that came highly recommended so if the gaps needed changing i'm pretty certain he would have done so .

 

Just curious as the why the bloke at the meet mentioned he had changed the gaps on his when he fitted the ignition system 

[johny]

As I say its quite possible youll get a higher spark voltage so it can jump a bigger gap (and also find weaknesses in HT leads/dizzy cap) but whether that translates to better combustion is another matter....

[AndyTV8]

I know this subject is often sensitive for some - my view is that usually, a move to electronic ignition will give you the opportunity to increase the plug-gap slightly to get a larger spark to ignite your mixture, the theory being that you stand a better chance of a more complete burn with a bigger spark (all other things being equal).

In practice, the generation of a larger spark will place a little more strain on the other parts of your HT system rotor arm, dissy cap, leads so it is important to ensure these are all in good order.

Personally, I run with a 30 thou gap on my 123Ignition set-up…..  I know some people who have gone to 32/35 and some that have stuck with 25 - the good part is that it is your car so you can set up up however you like and discover how it works for your engine   

……. Andy 

[johny]

Not convinced about the 'more complete burn' as surely once ignited the flame propagates through the mixture regardless of what the spark then does? Proper combustion is more about ensuring every fuel molecule is surrounded by sufficient oxygen so atomisation and mixing are the key factors...

[JohnD]

Moderns go for high tech mixture control, with swirl, tumble, stratified charge etc. to promote rapid, complete and efficient combustion, and more power.   The 1L three cylinder Ecoboost engine gets 170bhp, with plug gaps and coil voltage like those on a Standard Triumph.  It's all in the mixture!

Edited September 9, 2023 by JohnD

[Steve P]

12 hours ago, JohnD said:

The 1L three cylinder Ecoboost engine gets 170bhp

My daughters Ford Ecosport engine just destroyed itself, they run a Wet cambelt inside the engine which starts to degrade and blocks the oil supply. A well known and common issue with the early ones. 50,000 miles and it`s on it`s 4th Turbo. We are in a legal battle with the dealer to get our money back.

S 

[JohnD]

Different engine, Steve.   Unless  a post-2014 UK model.   But anyway, I quoted the 1L 3 cylinder Ecoboost to show that it's mixture control that gets power, not ignition volts!    I'm not "Which? for Cars"!!!

John

[68vitesse]

Had Lumenition Optronic in my Vitesse with a Lucas DB105 coil for years, recently fitted Bosh WR78? spark plugs starts better than before when I had NGK fitted, especially when the car has not been used for a few days, used plugs as bought and didn't even check the gaps.

Regards

Paul

[GrahamB]

Years ago I built a capacitor discharge  system,  It would run with 40 thou plug gap.  However, after a while it started missing badly when trying to accelerate; the plug lead insulation was breaking down.  Cleaning the plug, leads and distributor cap and returning the gap to 30 thou, rather than the specified 25 thou, and the car ran just as well without the insulation problem.  So, as others have said, as long as the mixture is ignited, a bigger spark is no advantage.  A bigger spark with more energy is only an advantage if the petrol air mixture is not optimum. 

If you have a properly made fire, you can light it with a single match.  Using a blow torch to light the fire will only achieve the same end result.

If using the same type of coil suitable for mechanical points, the HT output will not significantly change so I would keep the same plug gaps.

[Colin Lindsay]

7 hours ago, Steve P said:

My daughters Ford Ecosport engine just destroyed itself, they run a Wet cambelt inside the engine which starts to degrade and blocks the oil supply. A well known and common issue with the early ones. 50,000 miles and it`s on it`s 4th Turbo. We are in a legal battle with the dealer to get our money back.

S 

It's also a requirement that you use the correct oil, I think 5w 20 otherwise it will affect the belt. I changed daughter's Ecoboost oil a few months back, put in 5w 30 by mistake and realised almost immediately, so had to drain and refill. (The other 5w 30 oil went into the Mondeo so no waste...!)