Toystoretom
Living Legend
- Joined
- Feb 25, 2006
- Messages
- 2,449
Indexing Plugs...
The goal is to have the "open" gap of the electrode face the center of the cylinder, and not the wall. The theory is that the electriode may "cast a shadow" in the flame front as the flame kernel grows and tries to make it to the center of the combustion chamber if the electrode is in the way. This actually works to a small degree and results more in a smooth running engine more than anything else. It would take a dyno to measure any real horsepower gains, but there may be some.
The way you do this is to make a mark on the body of the spark plug indicationg which side the opening of the electrode is on. You then install the plug and turn it in so it is close to the proper torque and the opening is facing the center of the cylinder. If this can't be achieved you then have to add washers to make the direction of the opening correct.
If you have a true hemi style head that has a perfect central spark plug location this obviously isn't going to do much for you, but very few bikes have a combustion chamber like that and most plugs are off to one side.
I used to idex my plugs on my Nortons and it made it easier to start and I though they ran better.
The goal is to have the "open" gap of the electrode face the center of the cylinder, and not the wall. The theory is that the electriode may "cast a shadow" in the flame front as the flame kernel grows and tries to make it to the center of the combustion chamber if the electrode is in the way. This actually works to a small degree and results more in a smooth running engine more than anything else. It would take a dyno to measure any real horsepower gains, but there may be some.
The way you do this is to make a mark on the body of the spark plug indicationg which side the opening of the electrode is on. You then install the plug and turn it in so it is close to the proper torque and the opening is facing the center of the cylinder. If this can't be achieved you then have to add washers to make the direction of the opening correct.
If you have a true hemi style head that has a perfect central spark plug location this obviously isn't going to do much for you, but very few bikes have a combustion chamber like that and most plugs are off to one side.
I used to idex my plugs on my Nortons and it made it easier to start and I though they ran better.