wherezmytofu
03-08-2003, 10:59 AM
I have heard over and over again that copper tip spark plugs are better then platinum tips because copper is a better conductor, that is logic pulled from limited knowledge of physics.
Dielectric breakdown (a spark) is caused when the space surrounding the object begins to brake down because of the electrons, these momentary conduction paths appear in the air where the electric field has ionized air molecules, freeing some of their electrons.
Now let us look at a small principle. In self defense, women are taught to stomp on an aggressor's foot with the heel of her shoe. WHY? because you get more LB per square feet so you will inflict more damage. This works the same for dielectric breakdown. because the dielectric breakdown we are concerned with is in air. Air can only take charge per area. This means the smaller area you can get the charge into, the easier it is to get dielectric breakdown .
Now conductivity of an element is calculated by how many ohms of resistence there is per unit (length). now the differance between 2mm of copper compared to platinum is every small. now lets look at some numbers.
Electrical resistivity (microohm-cm) @ room temperature
Copper 1.678
Platinum 10.5
as you can see, platinum has much more resistance per unit lenght
Thermal conductivity at room temp W/cm C
copper 3.94
platinum 0.69
and you can also see that platinum is much less conductive then copper. now why am i still writing? these facts clearly show copper is better then platinum. like i stated before dielectric brake down is concerned about the smaller area you can get the charge into .
in earlier eras copper was used relitivly sortly as a weapon/armor element, because of the fact that is was a soft metal, it is relitively soft. In terms of a sword, the edge was hard to keep sharp due to the fact that copper is reitively not-hard. the harder a metal is the better it's ability to keep an edge. this is also true with the ability to make a tip as small as possible.
again lets look at some numbers.
Rockwell scale of hardness
copper b50-c18
platinum c48
as you can see platinum is much much harder then copper, this means you are able to work it to a smaller tip, this is the sole reason why platinum is a better spark plug tip then copper, because of the smaller tip, you are able to put more electrons in a unit area.
this is also why iridium is a better spark plug wire tip element then both. iridium has a rockwell hardness of C51.
what do i think is the best spark plug out there? bosch p+4 it has four tips, even tho iridium spark plug tips are smaller, you must compare it to four tips and since i have not seen any multi-tip iridium plugs i will have to go with the +4, even tho the iridium tips make a larger spark :)
Dielectric breakdown (a spark) is caused when the space surrounding the object begins to brake down because of the electrons, these momentary conduction paths appear in the air where the electric field has ionized air molecules, freeing some of their electrons.
Now let us look at a small principle. In self defense, women are taught to stomp on an aggressor's foot with the heel of her shoe. WHY? because you get more LB per square feet so you will inflict more damage. This works the same for dielectric breakdown. because the dielectric breakdown we are concerned with is in air. Air can only take charge per area. This means the smaller area you can get the charge into, the easier it is to get dielectric breakdown .
Now conductivity of an element is calculated by how many ohms of resistence there is per unit (length). now the differance between 2mm of copper compared to platinum is every small. now lets look at some numbers.
Electrical resistivity (microohm-cm) @ room temperature
Copper 1.678
Platinum 10.5
as you can see, platinum has much more resistance per unit lenght
Thermal conductivity at room temp W/cm C
copper 3.94
platinum 0.69
and you can also see that platinum is much less conductive then copper. now why am i still writing? these facts clearly show copper is better then platinum. like i stated before dielectric brake down is concerned about the smaller area you can get the charge into .
in earlier eras copper was used relitivly sortly as a weapon/armor element, because of the fact that is was a soft metal, it is relitively soft. In terms of a sword, the edge was hard to keep sharp due to the fact that copper is reitively not-hard. the harder a metal is the better it's ability to keep an edge. this is also true with the ability to make a tip as small as possible.
again lets look at some numbers.
Rockwell scale of hardness
copper b50-c18
platinum c48
as you can see platinum is much much harder then copper, this means you are able to work it to a smaller tip, this is the sole reason why platinum is a better spark plug tip then copper, because of the smaller tip, you are able to put more electrons in a unit area.
this is also why iridium is a better spark plug wire tip element then both. iridium has a rockwell hardness of C51.
what do i think is the best spark plug out there? bosch p+4 it has four tips, even tho iridium spark plug tips are smaller, you must compare it to four tips and since i have not seen any multi-tip iridium plugs i will have to go with the +4, even tho the iridium tips make a larger spark :)