Walter Atkinson
Well Known Member
John:
**Assuming pre-ignition is the cause of the piston damage in that photo, how does one benefit from that knowledge?**
It's always good to know the truth--even if it's too late. (see below)
**If you just blow-torched a piston and rings due to aggressive leaning, how does semantics make it any different?**
None if you don't know what just happened and had no clue how to stop it. If, in fact, you do know what happened, you have a better chance of avoiding it in the future. For example, the assumption that the direct cause of that was aggressive leaning is very, very, unlikely. So unlikely that I dismiss it as a probable cause. Having the understanding to appreciate that reality is a result of precisie education on the topic based on the data rather than listening to pontificated "common knowledge" from the airport know-it-all or a mechanic who has never flown behind an engine monitor.
**In your estimation, what caused that kind of damage? How can it be avoided?**
That is likely pre-ignition damage. Based on hard data, we have ZERO incidenses of detonation causing that, even though the "common knowledge" will quite freguently erroneously label that as detonation damage.
The common causes of pre-ignition are (in order of frequency):
1) a cracked spark plug ceramic. (very common)
2) a helicoil tang sticking into the combustion chamber. (not too common)
3) a glowing carbon deposit. (so rare as to be essentially undocumented, but considered by many as the most common cause!) Go figure?
It can be avoided by doing inflight mag checks routinely to find weak plugs before they fail (I do in-flight mag checks on every flight right before the let-down), and by checking the cylinders for helicoil tang over extensions at the time of installation, and being able to identify the event on an engine monitor and knowing what to do to stop the event. We have a growing file of pilots who have done just that and saved their engines by knowing how to identify the problem within secoinds and act proactively to stop the event.
THAT is why properly "understanding" these phenomena is better than not understanding them.
It's kinda funny when one realizes that there are three types of pilots:
Those who make things happen; those who watch things happen; and those who wonder what happened.
It is up to each as to which group they wish to populate.
Being in the first group requires two things. Being willing to study and think and, above all, relying on the data rather than someone's opinion--including mine. NEVER believe me; believe the data.
Walter
**Assuming pre-ignition is the cause of the piston damage in that photo, how does one benefit from that knowledge?**
It's always good to know the truth--even if it's too late. (see below)
**If you just blow-torched a piston and rings due to aggressive leaning, how does semantics make it any different?**
None if you don't know what just happened and had no clue how to stop it. If, in fact, you do know what happened, you have a better chance of avoiding it in the future. For example, the assumption that the direct cause of that was aggressive leaning is very, very, unlikely. So unlikely that I dismiss it as a probable cause. Having the understanding to appreciate that reality is a result of precisie education on the topic based on the data rather than listening to pontificated "common knowledge" from the airport know-it-all or a mechanic who has never flown behind an engine monitor.
**In your estimation, what caused that kind of damage? How can it be avoided?**
That is likely pre-ignition damage. Based on hard data, we have ZERO incidenses of detonation causing that, even though the "common knowledge" will quite freguently erroneously label that as detonation damage.
The common causes of pre-ignition are (in order of frequency):
1) a cracked spark plug ceramic. (very common)
2) a helicoil tang sticking into the combustion chamber. (not too common)
3) a glowing carbon deposit. (so rare as to be essentially undocumented, but considered by many as the most common cause!) Go figure?
It can be avoided by doing inflight mag checks routinely to find weak plugs before they fail (I do in-flight mag checks on every flight right before the let-down), and by checking the cylinders for helicoil tang over extensions at the time of installation, and being able to identify the event on an engine monitor and knowing what to do to stop the event. We have a growing file of pilots who have done just that and saved their engines by knowing how to identify the problem within secoinds and act proactively to stop the event.
THAT is why properly "understanding" these phenomena is better than not understanding them.
It's kinda funny when one realizes that there are three types of pilots:
Those who make things happen; those who watch things happen; and those who wonder what happened.
It is up to each as to which group they wish to populate.
Being in the first group requires two things. Being willing to study and think and, above all, relying on the data rather than someone's opinion--including mine. NEVER believe me; believe the data.
Walter
