Joined
·
1,448 Posts
That post with the link to the PDF file was awesome! There's so much info in there I decided it was necessary to start its own thread. heh heh heh (btw I'm now officially a fan of the Yoshiyama-Tomita model)
Some seriously interesting stuff on that webpage if you decide to read it. Several things can affect the ionization sensing ability. Nictric Oxide's free electrons as it is ionized is often the bar for measuring cyllinder pressure and temp ... but Nitric and Nitrous Oxide are both ionized by platinum, which might upset the ballance in the cyllinder and certainly would make it think at least slightly more of the cyllinder was ionized than was really the case. Also ... in the Saitzkoff-Reinmann model the diameter of the electrode, and plug gap, would seem to have a great deal to do with the what the computer interprets from the signal.
In the Yoshiyama-Tomita model the tendancy for different size plugs to change the characteristics of the "thermal peak" are clearly stated. My larger copper elctrode that I installed should have hypothetically increased the sensitivity to knock. (though copper and platinum conduct differently) Yet I see more boost rather than less. (Though the car has recently decided to get a little spark missfire because of those copper plugs, so on to standard NGKs or Iriduims for me) Again showing the tendancy for platinum to exagerrate the knock sensitivity.
Also I found something very interesting in the Yoshiyama-Tomita model. As the flame front of combustion reaches the chamber walls in releases the + ions into the metal and allows for the second "flame peak". This means that hypothetically one could determine two things with the voltage chart: One, you could determind the regularity and shape of the flame front by observing how long the "flame peak" lasted. A very long and low flame peak would imply a very uneven combustion as not all of the flame wave reached the cyllinder walls at the same time. A very short peaky "flame peak" would imply a very regular combustion took place, in which all of the gas reached the walls nealy simultaneously. Knock is often described as "irregular combustion" when it is not severe, and knowing the shape of the wave front could help a great deal in increasing reliability and hp. Two, knowing the time it takes for a flame front to reach the cyllinder walls could help a lot in determining ignition timing. Knowing the speed of combustion at any peticular temperature and pressure allows you to time the ignition so that the maximum cyllinder pressure occurs when the piston is at its ideal postion. Which would be very handy when calibrating an engine with heavily modified internal parts.
I'm going to keep reading into this. Thank much for the info!! Always fun to read about new research!
Yours,
Adrian W
Some seriously interesting stuff on that webpage if you decide to read it. Several things can affect the ionization sensing ability. Nictric Oxide's free electrons as it is ionized is often the bar for measuring cyllinder pressure and temp ... but Nitric and Nitrous Oxide are both ionized by platinum, which might upset the ballance in the cyllinder and certainly would make it think at least slightly more of the cyllinder was ionized than was really the case. Also ... in the Saitzkoff-Reinmann model the diameter of the electrode, and plug gap, would seem to have a great deal to do with the what the computer interprets from the signal.
In the Yoshiyama-Tomita model the tendancy for different size plugs to change the characteristics of the "thermal peak" are clearly stated. My larger copper elctrode that I installed should have hypothetically increased the sensitivity to knock. (though copper and platinum conduct differently) Yet I see more boost rather than less. (Though the car has recently decided to get a little spark missfire because of those copper plugs, so on to standard NGKs or Iriduims for me) Again showing the tendancy for platinum to exagerrate the knock sensitivity.
Also I found something very interesting in the Yoshiyama-Tomita model. As the flame front of combustion reaches the chamber walls in releases the + ions into the metal and allows for the second "flame peak". This means that hypothetically one could determine two things with the voltage chart: One, you could determind the regularity and shape of the flame front by observing how long the "flame peak" lasted. A very long and low flame peak would imply a very uneven combustion as not all of the flame wave reached the cyllinder walls at the same time. A very short peaky "flame peak" would imply a very regular combustion took place, in which all of the gas reached the walls nealy simultaneously. Knock is often described as "irregular combustion" when it is not severe, and knowing the shape of the wave front could help a great deal in increasing reliability and hp. Two, knowing the time it takes for a flame front to reach the cyllinder walls could help a lot in determining ignition timing. Knowing the speed of combustion at any peticular temperature and pressure allows you to time the ignition so that the maximum cyllinder pressure occurs when the piston is at its ideal postion. Which would be very handy when calibrating an engine with heavily modified internal parts.
I'm going to keep reading into this. Thank much for the info!! Always fun to read about new research!
Yours,
Adrian W