Quote:
Originally Posted by Patrick L.
I've been flying over 50 years and a lot of it is done operating over-square. [ manifold pressure v rpm] [ also lean of peak]. Doesn't hurt anything when done correctly.
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I don't think lugging in a car bears any resemblance to 23/25 in an airplane. Go feather a Continental IO-520 at cruise power if you want to hear lugging. And there really isn't an automotive equivalent to operating over-square.
Quote:
Originally Posted by Patrick L.
However, some think lugging is what causes or can cause detonation. I suppose its a fine point or a matter of terminology. Detonation/ping/spark knock [ not pre-ignition] can be somewhat hard on an engine and is caused by too much load [ combustion temps and pressure] along with too much ignition advance.
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I think its more than terminology. Lugging is still controlled burning, but the cylinder charge is too much for the RPM/load. Detonation is uncontrolled too rapid burning which is too close to an explosion inside your engine. That's what octane does, it slows down the burn rate. This is also different than pinging from pre-ignition from carbon or retarded timing.
What do you fly?