Scott, Do you have enough data to allow one to reconstruct the timing algorithm of the Lightspeed system? Have you used a timing light to check the advance of individual cylinders to see if the advance is being computed equally for all? Just curious, as in my system for a 6-cylinder system I see a few unusual indications. For example, one EGT consistently runs higher than the others by maybe 40 degrees, but this is only with the LSE on. When running on the other side (magneto) the temperatures are very uniform. I had a failure of the LSE after about 30 where I heard a distinct combustion knock for a few cycles and then the EGT for 2 cylinders from two different channels went up by almost 100. Then all EGT's went up and became uniform - that's when it blew the fuse and I was running on the mag alone. Klaus fixed it just fine and it's been running good since, but that's only been a couple of hours. Another odd thing is that since it was repaired I have 3 cylinders that run about 40 higher than the others, 3,4 and 6. 3 and 4 are the same channel. I'm nervous about the ignition timing not being uniform from cylinder to cylinder.
from Scott: "Otherwise, remember that the timing is tied to power as represented by RPM and MAP. At idle (lo MAP, lo RPM), the timing would be quite advanced (35-38 DBTDC). At takeoff power (hi MAP, hi RPM), timing advance is minimal, i.e. 25 DBTDC. As power declines by an increase in altitude (lower MAP) and cruise RPM (2300-2500), the advance should increase towards 35 or so DBTDC. If running LOP causes a reduction in RPM or MAP, the advance should increase a bit further. Reduce all the timing numbers by 5 degrees if the compression ratio (CR) is greater than 8.7:1. .... Finally, if the above doesn't explain what you are seeing, re-check the actual timing with a timing light. If that is good, check the wiring and connections. The display is a Simpson volt meter showing hundredths of volts. The selector switch not only connects the appropriate source, but adjusts the display decimal point location.
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