“There was one slide that showed a badly eroded massive and it was blamed on "severe LOP operation”
Let me take a stab at this. I suspect what they said or at least meant was, the badly eroded electrode was caused by severe detonation as a result of lean operation. What I mean is, if you are at high power and 300-400 degF Rich of Peak and you lean to 50degF Rich of Peak, you are in what I would call a severe engine operation zone caused by leaning. That is, you are way too lean for Rich of Peak operation at high power. If you continue leaning to 60-100 degF Lean of Peak, you are what I would call a pilot with good engine mangagement skills. By continuing the leaning process you reduce peak cylinder pressures and therefore peak temperatures. The likelihood of detonation increases as temperature and pressure increase. By leaning to 60-100 degF LOP, you significantly reduce the likelihood of detonation from the 50 degF ROP setting.
Craig Berland
N7VG
As a matter of interest, Tempest made a presentation to our EAA meeting last night and they had a lot of good technical info, most of which backs up what we've been saying here:
1) Massives typically good for 500 hours, fine wire 1800 hours.
2) Iridium replaced platinum because of leaded fuel issues
3) Resistance should max out at 5000 ohms then replace plug. Champion has that problem and Tempest created their own "fired in" solution made by Honeywell that the company says solves the problem. The resistor is not there for radio interference but for capacitance reasons.
4) Dropping a plug is replacing that plug--no questions.
5) Gaps on massives can be closed, never opened because it cracks insulators.
6) Rotating plugs has real benefits and the rotation is listed on the Tempest website.
There was one slide that showed a badly eroded massive and it was blamed on "severe LOP operation". I have trouble understanding this link but maybe there's data to support it.
There was quite a bit of information given with good slides. If anyone wants a presentation for their group, it is worthwhile and a lot of data is on the tempest website.