spark plug gap style, back cut advantage?

[Dragsinger]

NGK builds a nice race spark plug, the "V" power plug. Very reasonable price, widely available, wide range of applications.

In addition, Autolite builds a good plug and it has the side electrode "back cut" or "Side gaped"

Do we have any test results showing any advantage for the side cut electrode?

[SSDiv6]

Originally Posted by Dragsinger

NGK builds a nice race spark plug, the "V" power plug. Very reasonable price, widely available, wide range of applications.

In addition, Autolite builds a good plug and it has the side electrode "back cut" or "Side gaped"

Do we have any test results showing any advantage for the side cut electrode?

It depends on the application. For engines with high dome pistons, the Autolite Racing plug is great, as long as you index the plug. This means, several boxes of plugs to find plugs that will align properly. For most applications, my preference is NGK; greater selection, easier to find and lower cost. Don't forget Champion; they also make a great racing plug too.

As regards to test results, it is hard to quantify which plug is better due to the many variables involved as regards to ignition systems, plug gap, choice of fuel, timing, compression and fuel system settings. The best way to know which plug is good for you is track testing and reading the plugs with a good spark plug reader such as an Otoscope. There are many sold by Moroso, Jegs and others at very high prices.

The best deal for a great Otoscope, and an affordable price is the one sold by Dr. Mom Otoscopes Inc. Their website is: http://www.otoscopes.org/ or http://www.drmomotoscope.com/

For the price you will pay for the others, you can buy several of the basic ones or buy their high end Fiber Optic LED version with a lifetime warranty.

[Dragsinger]

Thanks Racer,

I appreciate the note.

[skj283]

Originally Posted by SSDiv6

the Autolite Racing plug is great, as long as you index the plug..

why are the autolites any more sesitive to indexing than any plug. not challenging u, dont get me wrong. just intrigued. i run them and index them for the record. so dont think im being disrespectful.

[SSDiv6]

Originally Posted by skj283

why are the autolites any more sesitive to indexing than any plug. not challenging u, dont get me wrong. just intrigued. i run them and index them for the record. so dont think im being disrespectful.

No, you are not being disrespectful. The cut back ground electrode changes the firing pattern and flame kernels of the spark plug. Also, when you index the spark plug, you are reducing spark plug and exhaust valve wetting problems that are caused by turbulence.

..and, if you have domed pistons, you can eleiminate the probability of the piston hitting the ground electrode.