Author Topic: Engine knocking sound  (Read 1087 times)

Offline flight17

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Re: Engine knocking sound
« Reply #15 on: July 20, 2012, 09:46:38 PM »
You seem to be assuming a simple oil leak instead of mangled engine parts getting pounded as long as the engine is running.
what happened with us was that a crack formed in the cylinder head. As the engine warmed up it expanded. The cylinder head then pinched the pushrods causing the pushrods to break and blow through its case. As the cylinder head continued to separate cooling fins broke free and entered the compression chamber. The top of the cylinder was held on by one side of the jug.

Other than the oil trailing off the nacelle, the only indication that something was wrong was the fact that they couldn't lean the engine. Every time they tried it started to backfire. There was no sound change.

This is us landing on that flight... And here are some pics after we parked
http://m.youtube.com/watch?v=05Qau-8APOk




119th Riffle Tank Regiment leader -Red Storm Krupp Steel Scenario

Active Member of Air Heritage Inc. http://airheritage.org/

Offline icepac

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Re: Engine knocking sound
« Reply #16 on: July 21, 2012, 08:11:26 AM »
Many people aren't gifted with being able to hear an engine that is in distress yet still seemingly ok.

I remember a C130 we loaded at Dulles (signature) and I could hear that the bearings were done in one of the engines and mentioned it to our FBO A&P and we discussed it to the point of argument before I convinced him.

We approached the pilots who blew us off because they were looking at the ferrari and multiple high dollar watercraft they were transporting.

The C130 suffered an engine failure and had to land in new york a short time later.

Offline Widewing

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Re: Engine knocking sound
« Reply #17 on: July 22, 2012, 12:38:26 PM »
what happened with us was that a crack formed in the cylinder head. As the engine warmed up it expanded. The cylinder head then pinched the pushrods causing the pushrods to break and blow through its case. As the cylinder head continued to separate cooling fins broke free and entered the compression chamber. The top of the cylinder was held on by one side of the jug.

Other than the oil trailing off the nacelle, the only indication that something was wrong was the fact that they couldn't lean the engine. Every time they tried it started to backfire. There was no sound change.


I've lost several R2800s in C-118s and a C-131. Usually, a cylinder suffers a failure (heads blow off, or partially blow off), con rods break or any number of various mechanical failures. However, the engine will make good power on the remaining 17 cylinders. Your biggest risk is fire. If feasible, feather the prop and shut it down.

Depending upon the problem, you may need to change the engine, or more commonly, replace the affected cylinder. That will be determined after the post-flight inspection.



My regards,

Widewing

YGBSM. Retired Member of Aces High Trainer Corps, Past President of the DFC, retired from flying as Tredlite.

Offline FLS

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Re: Engine knocking sound
« Reply #18 on: July 22, 2012, 01:14:08 PM »
what happened with us was that a crack formed in the cylinder head...

Glad you made it.

In Aces High as far as I know the engine is only damaged by projectiles, overspeeding prop, or collisions. When the engine is damaged by projectiles the oil leak is from the engine damage and is not the cause of the engine damage though it may be the cause of the engine eventually stopping.