Cyllinder base oil leak, repair or defer?

[1RTK1]

In Light detonation pressure still rises.
Don’t know about an o200; but It can happen in larger n/a engines.



“That's what's called "super knock", it won't happen inside an O200. Maybe a highly stressed turbocharged engine, but not a N/A engine.”

 

[mtuomi]

In Light detonation pressure still rises.
Don’t know about an o200; but It can happen in larger n/a engines.

View attachment 66435

“That's what's called "super knock", it won't happen inside an O200. Maybe a highly stressed turbocharged engine, but not a N/A engine.”

Original point was stretching bolts. That's nowhere near those levels.

 

[Tom-D]

"Detonation". You clearly have no clue what happens inside an engine.
(No, detonation never happens inside a piston engine, but I'll humor the incorrect term for this).

Just FYI: It has NOTHING to do with stretching bolts.
Knocking/detonation/whatever you want to call it happens AFTER the combustion event. The peak pressures caused by it aren't different in a meaningful way to cause issues.
Sorry, don't call people freaking idiots, when you have no clue what you are talking about.

During the mis-fueling in Ca. a few years ago, both manufacturers disagree with you, You don't know what the OP has been feeding this engine. Yet you rag on me like you are the expert on every thing.
50% of the 0-200s I tear down have case fretting from over stress of the case thru bolts.
You have no clue on how this engine in question was treated, run or anything else. Detonation occurs for several reasons, but still is the biggest offender of high cylinder pressure.
Do you even know which prop is on the 0-200? Low RPM and high MAP can result from a high pitch cruise prop.

The point is, you don't know squat about the engine, yet criticize me

 

[Tom-D]

Original point was stretching bolts. That's nowhere near those levels.

How do you know that? are you Psychic?
Do you know how this engine was treated in the past?

There is no other way a cylinder can get loose other than a stretched stud or thru bolt.

 

[Tom-D]

“That's what's called "super knock", it won't happen inside an O200. Maybe a highly stressed turbocharged engine, but not a N/A engine.”

Unless it is mis-fuel, wrong prop, or several other things that slow the RPM too much for the MAP.
Why do you believe we don't jamb the throttle in quickly? Low Oct fuel and quick opening of the throttle will cause a knock, you may not hear it, but the damage caused is collective.

 

[Tom-D]

Can you cite a reference.
I’ve seen graphs of engine monitors where temps runaway very quickly in airplanes. What is your reason for that? Detonation or pre-ignition

Wrong timing, failing mags, several other things.

 

[Tom-D]

Just FYI: It has NOTHING to do with stretching bolts.
Knocking/detonation/whatever you want to call it happens AFTER the combustion event. The peak pressures caused by it aren't different in a meaningful way to cause issues.
Sorry, don't call people freaking idiots, when you have no clue what you are talking about.

Then you tell us how cylinders get loose, Studs are torqued to spec, nuts don't back off, many cases I see torque strip still in place, yet we see case fretting, leaking cylinders, the only thing that will do that is high cylinder pressures, you say it's not detonation, then what is it?

 

[1RTK1]

Can you cite a reference.
I’ve seen graphs of engine monitors where temps runaway very quickly in airplanes. What is your reason for that? Detonation or pre-ignition

Wrong timing, failing mags, several other things.

That was a question to the other person that said detonation don’t increase cylinder pressures and that I was taught wrong.

 

[Tom-D]

That was a question to the other person that said detonation don’t increase cylinder pressures and that I was taught wrong.

OH kay. Maybe we all were, New error thinkers, new terms for old ideas. yet it is the same old engines we have been running for decades

 

[Tom-D]

you may want to consider the reason the FAA/TCM wanted to reduce the timing on the 0-200.
Pressures were high enough to crack cylinders. You think that's all it did?

http://rgl.faa.gov/Regulatory_and_G...5FD3727F609E1E0686256848004B6075?OpenDocument

 

[Cap'n Jack]

Read it in context to your previous post ,, it'll make perfect sense.

Even within that context, it still doesn't. You were either involved, or you weren't. Inspection of the workmanship on the owner build, watching, and doing safety wire work is certainly involvement. Perhaps you define involvement another way?

 

[Cap'n Jack]

Yeah and will probably catch hell for it too.

IMHO had the NTSB done a proper job and hardness tested the bolts, we wouldn't be here there would probably be an AD on every 0200/0300 that could possibly have these bolts in them.

Have there been any more incidents involving these bolts since then?

 

[Checkout_my_Six]

In Light detonation pressure still rises.
Don’t know about an o200; but It can happen in larger n/a engines.

View attachment 66435

“That's what's called "super knock", it won't happen inside an O200. Maybe a highly stressed turbocharged engine, but not a N/A engine.”

because the compression ratios are much lower.....

 

[Cap'n Jack]

The original engine oil screen remained installed despite the fact the engine was equipped with an oil filter. The oil screen was removed and it was noted that there was a significant amount of contaminates consistent with metallic material as well as a significant amount of unidentified black colored substance.

The crankcase was intact and undamaged. The crankcase halves were split and the crankcase was visually inspected. It was noted that there was black sealant applied to the crankcase halves mating surfaces and there was no silk thread noted on the crankcase halve mating surfaces. It was also noted that the black sealant material was found in several of the oil galleys.

When Mr. Downey was asked what the black sealant substance was found on the cylinders and the crankcase during an examination of the engine and airframe on October 15, 2016, he replied that it was #2 Permatex. Mr. Downey said that it was a non-hardening substance, so if it goes through an oil pump it will not clog a passageway.

When Mr. Downey was informed as to why the black sealant, #2 Permatex, was not applied to the #2 cylinder, he replied that he omitted to apply the compound. He had to reason as to why it was not applied, just that it was omitted.

Why would one put #2 Permatex around the cylinders? Isn't the o-ring at the base of the cylinder supposed to seal the cylinder?

 

[Cap'n Jack]

Yes, why do you believe I was even involved, the owner did the torque, I watch and safety wired the bolts. two people involved, Snap-On torque wrench calibrated the week prior.
You guys had me convinced I screwed the pooch on this, And I lost a hell of a lot of sleep thinking I had some how hurt a dear friend, But no, thanks to a great diligent lawyer (blood hound). we find that we were f- with bogus bolts.

It was an NTSB investigation, not an FAA investigation. They blamed other sloppy workmanship for the failure.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The loss of engine power due to the mechanic's inadequate tightening of the crankshaft gear
retaining bolts during an engine overhaul, which resulted in fatigue failure of the bolts and the
crankshaft gear dowel pin that allowed the crankshaft gear to separate from the crankshaft.

Sounds like you forgot to tell the NTSB that. The record indicates that you told them that you did the work. Also, it's your signature in the logbook.

When Mr. Downey was asked if he had a calibrated torque wrench, and if he used it to install the crankshaft gear, he replied “YES” to both questions.

Mr. Downey was asked if any of the accessories were sent out to other vendors during the engine overhaul process, specifically the starter, carburetor, and magnetos. Mr. Downey replied that during the entire overhaul process no components were sent out, that some were inspected and repaired by himself.

Mr. Downey was asked by the IIC what manual or instructions did he use to overhaul the accident airplane’s engine. Mr. Downey replied he used the Continental O-200 Overhaul Manual, which was dated January, 1984, which was the date of approval by the Federal Aviation Administration.

This thread Is starting to look like a purjury trap.

 

[Tom-D]

Have there been any more incidents involving these bolts since then?

yes.

 

[Tom-D]

It was an NTSB investigation, not an FAA investigation. They blamed other sloppy workmanship for the failure.

That is a lie.

 

[Cap'n Jack]

Have there been any more incidents involving these bolts since then?

yes.

Have any references for those incidents? Any proof?

 

[Kenny Phillips]

Then you tell us how cylinders get loose, Studs are torqued to spec, nuts don't back off, many cases I see torque strip still in place, yet we see case fretting, leaking cylinders, the only thing that will do that is high cylinder pressures, you say it's not detonation, then what is it?

Torquing is really not the best way to determine the "tightness" a bolt or stud; on our race engines, we measured stretch if at all practical to do so. Bolts and studs can also suffer plastic strain. But as you know, all kinds of things can cause that torque wrench to click without the fastener being at design stretch.

 

[Tom-D]

Torquing is really not the best way to determine the "tightness" a bolt or stud; on our race engines, we measured stretch if at all practical to do so. Bolts and studs can also suffer plastic strain. But as you know, all kinds of things can cause that torque wrench to click without the fastener being at design stretch.

but it is what the manual dictates. there are cases that our manuals call for stretch.

 

[Checkout_my_Six]

but it is what the manual dictates. there are cases that our manuals call for stretch.

where does it call for stretch?

 

[Tom-D]

where does it call for stretch?

To start, The 1 place I am familiar with is the Hamilton Standard Propeller manual for the P-3
The hub half bolts get stretched to fit the go/no go gauge.
Some engines do the rod bolts that way.
0-200/0-300 simple torque charts in the overhaul manual.

 

[Checkout_my_Six]

P-3?.....wow Tom.