alpinelakespilot2000
Well Known Member
Following the advice of Mike Busch from a Jan 2012 Sport Aviation column, and having recently completed my first condition inspection (at which time I cleaned and gapped all plugs), I ran an ignition stress test on cross-country last weekend. Unfortunately, I really don't have much idea how to interpret the results.
For reference, the CHT's are clustered at the bottom of the chart (with the temperature scale to the left) and the EHT's are clustered at the top of the chart (with the temperature scale to the right). Each mag was run individually for about a minute each with a minute in between to allow things to restabilize. My power setting was about 65%, as LOP as possible without getting engine roughness. In addition, FWIW, normal pre-takeoff run-up check of my Slick mags at 1800 rpm showed a similar 40-50 rpm drop on each mag.
1. What's likely going on with my #4 EGT when I do the LEFT MAG test? It spikes quite a bit higher relative to its norm than do the other EGTs.
2. What might account for no apparent EGT rise on #1 during the LEFT MAG test?
3. Most curious to me:
*On my LEFT MAG test my #1 and #3 CHT's drop while my #2 and #4 CHT'S stay the same
*On my RIGHT MAG test the opposite happens: #2 and #4 CHT drop while #1 and #3 continue their climb back to normal temps.
I would have thought my CHTs would all rise and fall together given that both mags fire plugs on all four cylinders. (???)
4. Any other observations one could make?
Thanks for any thoughts.
For reference, the CHT's are clustered at the bottom of the chart (with the temperature scale to the left) and the EHT's are clustered at the top of the chart (with the temperature scale to the right). Each mag was run individually for about a minute each with a minute in between to allow things to restabilize. My power setting was about 65%, as LOP as possible without getting engine roughness. In addition, FWIW, normal pre-takeoff run-up check of my Slick mags at 1800 rpm showed a similar 40-50 rpm drop on each mag.
1. What's likely going on with my #4 EGT when I do the LEFT MAG test? It spikes quite a bit higher relative to its norm than do the other EGTs.
2. What might account for no apparent EGT rise on #1 during the LEFT MAG test?
3. Most curious to me:
*On my LEFT MAG test my #1 and #3 CHT's drop while my #2 and #4 CHT'S stay the same
*On my RIGHT MAG test the opposite happens: #2 and #4 CHT drop while #1 and #3 continue their climb back to normal temps.
I would have thought my CHTs would all rise and fall together given that both mags fire plugs on all four cylinders. (???)
4. Any other observations one could make?
Thanks for any thoughts.
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