Originally Posted by Roflhat
Sorry I misunderstood!
yeh I'll look into it for sure. I've got uprated - nakuru - coils (from a motorbike) and iridium plugs on it on the moment. So dyou reckon an increased plug gap would increase power?
It will to a certain extent. Haven't found anyone that has provided an equation or rules of application. More of try and test in gap steps starting at 1-5/1000 from where you are at. There are general guides that should get you started. Would guess diving into the performance motorbike world as a start? If you go too far, not sure what happens with your setup. Most likely misfires with your coils unable to produce an adequate voltage for the wider gap.
Getting a larger gap which is closer to the center of the gas/air mixture is what you want. This is why I was saying that I found the NGK plugs to be shorter than others when you compare them for the exact same application. In my testing, I found that a wider gapped NGK was equivalent to a normal gapped Champion because the Champion extended further into the chamber.