I think the plug's I'm running are the NGK 97506It looks like the ngk 94201 B58 spark plugs would be a good match for this setup. It’s a step colder and the dimensions are identical to the 97506. Plus the terminal is flat.
Would be interesting to see if it we can run the 94201 stock gap (0.75mm) with the B58 coils @ 25 psi.
I think the plug's I'm running are the NGK 97506
Doesn't that also mean the 94201 will run hotter, since there is less metal to conduct the heat away ?.The 94201‘s Centre electrode has a diameter 40% smaller than the 97506.
The smaller the electrode diameter the less the voltage required for the spark to jump the gap.
heat rating is the same at 8.Doesn't that also mean the 94201 will run hotter, since there is less metal to conduct the heat away ?.
Hmm, how do you think they managed that then. as a thinner electrode usually means the plug runs hotter.heat rating is the same at 8.
It’s not the diameter size of the electrode tip that is important to determine heat range of a spark plug. It’s how much plug porcelaine insulator is exposed at the electrode face. More there is porcelain acting as conductive insulation the more the plug is colder.Hmm, how do you think they managed that then. as a thinner electrode usually means the plug runs hotter.
Well the Porcelain doesn't conduct much heat. But it would certainly shroud the central conductor from absorbing more combustion heat. Though I think I will stick with the 97506 plugs for now. As I'm really not convinced a smaller tip is a good thing. I mean my engine runs pretty sweet right now even with N54 OEM coils. So with the B58 coils its going to get double the energy even with the same dwell settings.It’s not the diameter size of the electrode tip that is important to determine heat range of a spark plug. It’s how much plug porcelaine insulator is exposed at the electrode face. More there is porcelain acting as conductive insulation the more the plug is colder.
The other thing is the terminal design. The b58 plugs have a flat design that goes with the b58 coils.
The 97506 has a cup design which I suspect has less contact area to the coil.
In most papers that I have read - smaller core diameter does better in getting the arc across to the shroud largely due to a lower voltage requirement ...
The main idea is whether with the smaller voltage requirement, flat terminal, larger energy displacement - we can get the spark arced with stock gap size (0.75mm) with 25 psi boost.
Waiting for the stock valve cover brackets to be available and have this tested out ...
The B58 spark plug is two step colder as the stock spark plug.It looks like the ngk 94201 B58 spark plugs would be a good match for this setup. It’s a step colder and the dimensions are identical to the 97506. Plus the terminal is flat.
Would be interesting to see if it we can run the 94201 stock gap (0.75mm) with the B58 coils @ 25 psi.
U run these in any of your cars ?If anyone is looking we offer them here for $15 each, with gapping a few different specs available if you want to make sure they are gapped correctly.
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