I pulled my pmag and note some play. Reading the service material led me to call Brad at EMAGAIR to see if he could quantitate “excessive” play. Makes it sound like some play is acceptable.
Now that our fleet is growing and making maintenance observations, I wonder what your experience is with the pmag? Brad notes that there are better and worse engine, prop, and ignition combos but no one does the upfront testing in experimental. We’ll have discover and report them.
For my case, I received a Thunderbolt IO390 with one Slick mag on left and one pmag ( EMAG P114L4 ), I hung the standard 72” Vans Hartzell prop (HC-C2YR-1BFP/F7497-2) and found play in the pmag at 168 hours. I am sending it off for an eval. Is the play excessive? I will report back.
Brad indicates that there are two failure modes as play increases. The generator will stop generating, and / or the unit will stop sensing where to fire. Brad said that there was nothing catastrophic that might occur. I probably should have probed further on this.
Once I receive the pmag back, I will check for play to understand the “new” condition. I am thinking I will build a fixture and use a dial indicator to check and track change over time until failure.
Brilliant or stupid?
What are your combinations and experience?
Thanks
Now that our fleet is growing and making maintenance observations, I wonder what your experience is with the pmag? Brad notes that there are better and worse engine, prop, and ignition combos but no one does the upfront testing in experimental. We’ll have discover and report them.
For my case, I received a Thunderbolt IO390 with one Slick mag on left and one pmag ( EMAG P114L4 ), I hung the standard 72” Vans Hartzell prop (HC-C2YR-1BFP/F7497-2) and found play in the pmag at 168 hours. I am sending it off for an eval. Is the play excessive? I will report back.
Brad indicates that there are two failure modes as play increases. The generator will stop generating, and / or the unit will stop sensing where to fire. Brad said that there was nothing catastrophic that might occur. I probably should have probed further on this.
Once I receive the pmag back, I will check for play to understand the “new” condition. I am thinking I will build a fixture and use a dial indicator to check and track change over time until failure.
Brilliant or stupid?
What are your combinations and experience?
Thanks