Hi all,
 
Has anybody experimented with plug gaps? And if so what kind of ignition do you have?
 
I have always just put plugs in without measuring them but after upgrading my coil and having electronic ignition I thought about playing around with the gaps in my 2L.
 
Standard gaps specified in my manual are 0.75+/-0.05mm. From the shop they came about 0.75mm and I widened them to 1mm just to see what it would do. I expected it to run like junk but seems to idle stronger than it used to.
 
Would love to hear anybody's opinions on the matter. Doesn't matter if you have a different motor, any feedback is good feedback.
 
Cheers,
Ryan

I am going to reply to myself lol
 
Using Pertronix coil and ignition module, have been playing around with plug gaps for the past week. (NGK AP6FS)
 
Tried 0.75mm, 0.85mm and 1.00mm
 
No noticable difference between 0.75mm and 0.85mm, however when openning the gap to 1mm there is a very noticable difference in the way the car drives:
- smoother idle and cruising at low rpm
- far less throttle input needed to slowly accelerate
 
Compared to the smaller gap the car feels like it accelerates much more freely. Car felt like it was labouring with the smaller gap.
 
Dont know whether anybody was actually interested in that but thought Id put it up here. Surprising how much difference it made to how the car felt.
 
Cheers,
Ryan

Definitely interested - thanks for posting.  Might try it myself when I get the car back on the road.

I used the thickness of a hacksaw blade to do my plug gap( about 1.1mm) , pinto with Sierra electric dizzy and amp . Seems to generate a greater spark giving better all Round running performance. Also used to do an old nascar trick and cut the Outer electrode back So the spark was more sideways and had a direct path to ignite the petrol.

Flighter
Definitely interested - thanks for posting.  Might try it myself when I get the car back on the road.

Haha im glad! cheers
 
Thanks martymexico, i might try those shortened outer electrodes. Ive got an old set of plugs, i might give it a go.
I used to file the ends of the outer electrodes to produce a very sharp edge with the theory that it is easier for the spark to jump across a sharp surface.
 
If anybody else had played around with gaps please post your results!
 
Cheers,
Ryan

Ryan,
Did you bypass the ballast resistor wire in the ignition feed for that Pertronix coil? If it is a non ballast type coil and you did bypass it then you should get higher spark voltages and so be able to run wider plug gaps. This should potentially give better performance. That's the theory.
GG.

Hi GG, I ran a 12volt wire from just after the ignition barrel directly to the coil. The pertronix coil can be used with or without ballast so I chose to run a 12 volt wire thus have more power/greater spark.
 
It would be interesting to see where the limit is in terms of maximizing the gap before performance diminishes with just an uprated coil and ignition module. I like the idea of not spending megadollars on an msd system however I do believe they would be optimal in a quicker (more expensive) motor.
 
Cheers,
Ryan
 

Tried this today, set my spark plug gap to 1 mm. Use to have a slight miss at the start of acceleration, I thought this was because of my dodgy carb tuning but not so.