Engine anomaly - Detonation!

[kortopates]

I thought I'd show an example of an engine anomaly that pilots need to be prepared to take swift action to save their engine cylinder(s). Many pilots have a very nice engine monitor installed but its mere presence doesn't do anything to keep you safe., That's up to the pilot to keep the monitor in their scan and learn as much as they can about how to use them. I know many here have saved themselves multiple times from impending catastrophic damage because they were using their engine monitors as intended. For those learning I offer an an example of severe classic Detonation. The pilot became a Reno Racer with 25" of over boost over redline. Would you have caught this? It only took a little more than minute to cause the catastrophic damage below. CHT6 got as high as 719F the cylinder was over redline for about 90 sec and every cylinder exceeded redline. Redline MAP and RPM are almost identical to a intercooled 231 or 252/Encore.

First the data:

What happens is the overboost creates a very lean condition because the fuel system can't meet the demand of the added boost/air. So we see TIT go over 1700 and then the detonating cylinder EGT go up over 1800F causing its CHT go to 719F before the engine quite entirely - seizing.

From the picture you can see the molten aluminum remains of a piston.

Edited 4 hours ago by kortopates

[0TreeLemur]

Hey Paul- thanks for sharing this.  Any idea what caused the overboost?  That's crazy.  I've got an old manifold pressure gauge out of a P-51.  I think it is normal max at about 50 in Hg, with a military red line at 60 in case of emergency. 

I'm surprised the head didn't pop off the cylinder.

[1980Mooney]

1 hour ago, kortopates said:

I thought I'd show an example of an engine anomaly that pilots need to be prepared to take swift action to save their engine cylinder(s). Many pilots have a very nice engine monitor installed but its mere presence doesn't do anything to keep you safe., That's up to the pilot to keep the monitor in their scan and learn as much as they can about how to use them. I know many here have saved themselves multiple times from impending catastrophic damage because they were using their engine monitors as intended. For those learning I offer an an example of severe classic Detonation. The pilot became a Reno Racer with 25" of over boost over redline. Would you have caught this? It only took a little more than minute to cause the catastrophic damage below. CHT6 got as high as 719F the cylinder was over redline for about 90 sec and every cylinder exceeded redline. Redline MAP and RPM are almost identical to a intercooled 231 or 252/Encore.

First the data:

What happens is the overboost creates a very lean condition because the fuel system can't meet the demand of the added boost/air. So we see TIT go over 1700 and then the detonating cylinder EGT go up over 1800F causing its CHT go to 719F before the engine quite entirely - seizing.

From the picture you can see the molten aluminum remains of a piston.

The picture you attached is not visible - I tried to view with an iPhone and a PC - but it is just a long alphanumeric string.

[kortopates]

The picture you attached is not visible - I tried to view with an iPhone and a PC - but it is just a long alphanumeric string.

thanks - hopefully fixed now

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