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Comment by davidgould | Hacker News Reader

V* engines share a common crankshaft with both banks, that's the V part. Please cite any specific V12 aircraft engine that can have one bank of cylinders shut down. I don't believe one exists.

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>Please cite any specific V12 aircraft engine that can have one bank of cylinders shut down.

The RED A03 Engine[0], which is what this sub-thread is about.

>Two cylinder-bank redundancy concept for high safety.

>Robustness and safety are incorporated into the engine design. The two 6-cylinder banks are capable of independent operation. All critical engine sub-systems are mutually-independent.

[0] https://red-aircraft.com/

Except the crankshaft...

Oh, and any mechanical issues with pistons or valves in one side will jam the crankshaft, therefore stop the other half working...

And that crankshaft needs some kind of oil... And a pump to pressurize that oil. And if a leak forms anywhere the oil drains out and the crankshaft seizes. Pretty hard to lube one crankshaft with two redundant and isolated oil systems...

Overall, I'd call the engine 1.5x redundancy...

Agreed. Based on the documents, I also don't see any protection against metorites or the sudden loss of oxygen in the planet's atmosphere. That's not even 1x redundancy really.

Most V engines can operate this way -- obviously not at full power. GM, Daimler, Honda, and FCA do this on some of their production v6, v8, and v12 engines. It is not that difficult to skip some cylinders, engines have a lot of rotating momentum.

https://en.wikipedia.org/wiki/Multi-Displacement_System

https://en.wikipedia.org/wiki/Active_Fuel_Management

https://en.wikipedia.org/wiki/Active_Cylinder_Control

https://en.wikipedia.org/wiki/Variable_Cylinder_Management

There is a huge difference between being able to operate in a managed cylinder deactivation mode vs being able to operate when one whole bank is experiencing some kind of catastrophic failure.

True, I was addressing the question at face value.

Of course the crankshaft is shared. It is oil, fuel, and cooling that can be shut down to prevent leaks.

Although I can't find a reference to an aircraft engine, Chrysler did have a variable displacement tech on its third gen Hemi engines that could turn off one bank of the V8.

Ref: https://en.wikipedia.org/wiki/Multi-Displacement_System

I don't know much about aircraft engines, but in fact straight-6 engines are inherently balanced, and a V12 is fundamentally two straight sixes, so at least in theory it would be quite possible to stop using one bank of cylinders if some of their cylinders suffered some form of non-catastrophic failure.

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