Electronic ignition and spark plug gaps

[Waynebaby]

Hi all,

 

I've read in various places that running electronic ignition allows the spark plug gaps to be opened up, with a consequent improvement in performance from a larger spark. The thing that is bothering me is that I can't figure out why this should be the case. If most after-market electronic ignition systems such as Lumention are simply an electronic switch to replace the points I can't see why this should change the voltage at the plug (the coil remains the same) Can someone tell me if I am missing something or if the suggestion that the plug gap can be opened up is just an old wives tale?

 

Wayne

[dougbgt6]

Here are some MG types wittering on about it. Not sure what to make of it, never re-gapped mine and they work fine.

 

http://www.mgexp.com/phorum/read.php?1,615002

[Waynebaby]

Thanks Doug - Plenty of wittering but nothing conclusive! The dwell angle provided by a Lumention system on a six cylinder engine is 45 degrees cf. the standard 41 degrees on a Delco-Remy dizzy (35 degrees on a Lucas) and I can't imagine that making enough difference to the recuperation time of the coil to influence the power of the spark significantly. I think I'll just stick with the standard gap, which seems to work fine with the lumention system.

 

Wayne

[Colin Lindsay]

Electronic ignition in its' most basic form only makes for a more reliable spark at a more precise time; it can overcome worn points to a certain amount and thereby give a stronger spark allowing the gap to be opened slightly.... running a hotter coil at the same time will improve the strength of the spark and allow it to jump a larger gap.

[Gully]

My GT6 has a lucas AB12 electronic ignition fitted. I experimented with different plug gaps (having re-gapped from 31 thou to the book value when I first serviced the car) and found 30 thou to be best - car seemed 'flat' with the gap in line with the handbook.

 

Gully

[Pete Lewis]

Always start with stick to the basics and if needed work from that base data.

 

A bigger gap takes longer to jump , , higher HT can blow rotors amd jump caps

 

especially some of the poor aftermarket examples

Pete

[AtRo Racing]

Here are some MG types wittering on about it. Not sure what to make of it, never re-gapped mine and they work fine.

 

http://www.mgexp.com/phorum/read.php?1,615002

I will tell you that Jeff from Advanced Distributors is spot on with what he has said. I have been using him for years now on all of our restorations and service jobs. Once he has rcurved and rebuilt your distributor you will never go anywhere else. The first tome I used him I thought I had put in a new engine in my Midget.

 

Robbie