Caution - Religious discussion, click here only if you can handle this topic.

[Roger Wilco]

...the University of North Dakota (isn't that where Professor Schickele used to teach?).

You may be thinking of the University of Southern North Dakota at Hoople, where he composed, among his many famously forgotten works, the piece Thermodynamic Loops: The Otto Cycle. Notably absent from the premiere (and only) performance was Schickele's esteemed colleague, Walter Piston. Word is that Schickele was attempting to plagiarize an earlier work of George Antheil, Ballet Mechanique, but was unable to blackmail any filmmakers into collaborating on the project. Although a resounding failure with critics, the audience, and the musicians, Thermodynamic Loops... is credited with paving the way for Karheinz Stockhausen's absurdist Helikopter-Streichquartett, and most preposterously, Lou Reed's Metal Machine Music, which Schickele's detractors point to as his most loathsome "accomplishment." Detonation, by comparison, is a slice of heaven.

 

[Half Fast]

You may be thinking of the University of Southern North Dakota at Hoople,....

Ah, quite right. IIRC, he was a professor of musical pathology. USND was also home, I believe, of the world-renounced Okay Chorale.

We must also remember to forget such astounding works as The Abduction of Figaro, the Unbegun Symphony, and Hanzel and Gretel and Ted and Alice. In fact, if you find The Abduction of Figaro will be performed near you I'm sure you will find it a rare treat (that is, not well done). Don't fail to miss it.

 

[tspear]

I over-slept and missed church.

If the only variable that changed in the UND process was the fuel, and the only out of spec result was valve rescission, then whether it is blamed on detonation or something else doesn’t matter - the root cause is the fuel change. The corrective actions can include operating the red knob differently, different valve seat specs, reformulating a different fuel iteration, etc.

It does matter however in knowing what part of the fuel change caused the issues in order to select the proper corrections.

Um no. At least not in the public information. They did not measure anything before hand, did not monitor, did not check MX records... they made a single assumption that there was one variable at play on the start of a new semester with new instructors....

Tim

 

[455 Bravo Uniform]

Um no. At least not in the public information. They did not measure anything before hand, did not monitor, did not check MX records... they made a single assumption that there was one variable at play on the start of a new semester with new instructors....

Tim

I should not have made that assumption. My information is second hand or worse. I figured from this and other POA threads that it was a more controlled experiment/test.

 

[Lance F]

My goal for my Continental TSIO540NB engines is to keep CHTs at 380 or less. Temperatures in the mid teen altitudes have been +15 to as high as +20 dC ISA here in the southeast all summer. I can’t imagine how much of the $6 to $10 / gallon fuel we’re buying these days I would have had to feed these engines to meet that goal ROP. Would kill my range and wallet. Let’s say at more normal temps I’d be running 15 gph LOP. Yesterday I had to pull back to 14.5 gph to stay below 380 on the hottest cylinders. Still doing 188 kts TAS so not losing much speed. I’ve been flying LOP for 25 years now…Continental and Lycoming. All fuel injected I admit.

 

[Roger Wilco]

Ah, quite right. IIRC, he was a professor of musical pathology. USND was also home, I believe, of the world-renounced Okay Chorale.

We must also remember to forget such astounding works as The Abduction of Figaro, the Unbegun Symphony, and Hanzel and Gretel and Ted and Alice. In fact, if you find The Abduction of Figaro will be performed near you I'm sure you will find it a rare treat (that is, not well done). Don't fail to miss it.

That's why I came here to PoA, to forget Schickele and the whole P. D. Q. Bach thing. And then here you come...

Now I have to start all over again.

 

[Half Fast]

That's why I came here to PoA, to forget Schickele and the whole P. D. Q. Bach thing. And then here you come...

Now I have to start all over again.

You could always detox with a light dose of Victor Borge.....

 

[Roger Wilco]

You could always detox with a light dose of Victor Borge.....

Touché. Rich comedy for a red-box kinda crowd.

 

[pfarber]

2 clogged fuel injectors

How does ROP clog a fuel injector? Were the air passages clogged? The fuel line?

 

[Rick A]

How does ROP clog a fuel injector? Were the air passages clogged? The fuel line?

The forced landing happened very early (~200 to 300' AGL) during the first takeoff that followed a low altitude high power ROP cross country flight on a very cold winter day (~15 F OAT). Once landing on an adjacent runway, I needed to pump the throttle to keep it running in order to taxi back to the FBO.

Apparently, per the mechanic who did the repair, said crud (carbon?) must have cut loose, completely logging one injector, and partially clogging another.

Following cleaning all the injectors the engine ran fine.

 

[455 Bravo Uniform]

How does ROP clog a fuel injector? Were the air passages clogged? The fuel line?

Does the stem-side of the intake valve on a TCM injected jug get carboned up? If so then conceivably the injector orifice can as well when dumping more fuel. I am out of my expertise here…I know enough to be dangerous.

From a statistical standpoint, the more fuel you flow, the higher the chances of clogging, lol.

 

[M20K]

Apparently, per the mechanic who did the repair, said crud (carbon?) must have cut loose, completely logging one injector, and partially clogging another.

I'm not sure I'd take the leap that "...(carbon?)..." was the issue unless the mechanic or the FAA specifically said carbon from running ROP.

More likely a fuel injector would get clogged from garbage in the fuel or from the fuel boiling in the injector after shutdown and a sludge eventually building up. I guess some carbon vapor could go back up into the injectors after shutdown too, but none of this would be a result of running ROP. Maybe taxiing ROP, but even that I think might be a stretch.

 

[Rick A]

I'm not sure I'd take the leap that "...(carbon?)..." was the issue unless the mechanic or the FAA specifically said carbon from running ROP.

More likely a fuel injector would get clogged from garbage in the fuel or from the fuel boiling in the injector after shutdown and a sludge eventually building up. I guess some carbon vapor could go back up into the injectors after shutdown too, but none of this would be a result of running ROP. Maybe taxiing ROP, but even that I think might be a stretch.

This event happened in the early 1990's. My memory is clear about the mechanic explaining (a paraphrase) some crap / crud fully clogged one injector, and partially clogged another. I never asked him his opinion about why those injectors needed cleaning and where he thought the crud came from. The real cause could very well have been something different than what I always blamed it to be.

Since the engine issue occurred during the first take off after more than an hour cross country at low altitude in very cold temps, with the mixture nearly full rich, my non-mechanical assumption was something in the cylinders close to the injector nozzles suddenly cut loose.

That engine powered a recently purchased Mooney that was approaching the recommended 2000 hour TBO, and burning about a quart of oil every 3 to 4 hours. The oil turned fully jet black in color within 10 hours after an oil change. A filthy runner.

 

[M20K]

My memory is clear about the mechanic explaining (a paraphrase) some crap / crud fully clogged one injector, and partially clogged another.

Sounds like possibly from the boiling off of the fuel when it's hot and you shut down. It builds up a sludge or "crap" as the mechanic mentioned.

But then at this point I guess there's no way to know.

 

[Rick A]

Sounds like possibly from the boiling off of the fuel when it's hot and you shut down. It builds up a sludge or "crap" as the mechanic mentioned.

I have occasionally noticed dark crap near the screens in plain view outside the injector body in the cavity leading down into top of the cylinder. Will an excessive amount of sludge in proximity to these screens block or disrupt air flow into the injector body? And if yes, can that cause a sudden partial engine failure as I experienced?