Ajay Magge

Spark Gap Calculator

Hello guys,
I'm new to this forum. I have posted a link above, post which determines breakdown voltage required @ spark plug tip. I just wanted to know which formula have the used to determine the same. Any help would be great.

voltage.value = Math.round((4.3+136*((pressure.value/101.3)/(temperature.value*1+273))+324*((pressure.value/101.3)/(temperature.value*1+273)*(gap.value*25.4)))*1000)

This is what i got from the page source. Please tell me what factors are 4.3,136 and 324

thank you in advance

9krpmrx8

iTrader: (46)

What are you trying to accomplish? RX-8 plugs come pre gapped.

iTs Ghastly

If you're asking just to ask, Charles has your answer, but 9k is right, our 8 plugs are the exact gap they need to be right out of the box, best not to mess with them, you arnt going to optimize anything, just cause yourself issues.

Ajay Magge

I want to have a generic equation to calculate required gap, w.r.t to parameters like dynamic pressure, compression ratio, temperature, and other parameters if any. I'm not just asking , im a student/intern working on hardware and on some documentation on optimization of engines.

wannawankel

The 101.3 is a constant from chemical engineering equations - essentially used to convert from kiloPascals (pressure in SI units) to other units. So there are 14.696 psi (lbs/in2) in 101.325 kPa also written as 14.696 psi/101.325 kPa. For those in the UK the conversion for using bars of pressure is 1.01325 bar = 101.325 kPa pressure.

273 is the conversion from temperature in Celsius (°C) to degrees Kelvin (°K): C + 273 = K. Kelvin is used often in scientific applications since 0 degrees Kelvin is absolute zero (where no molecular motion exists).

wannawankel

25.4 is mm to inch conversion

Ajay Magge

Any idea on these values in the above equation (factors 4.3,136 and 324)