Ugly Crank

[GAHorn]

The owner/operator is ultimately responsible for the airworthiness of the engine and airplane.

A defense for the owner/operator might be improper maintenance performed that the owner/operator would not have reasonable cause to know. (Did he know about it? Or should he have known about it?)

The pilot is responsible for the proper operation of the engine (which includes pre-flight determination of airworthiness per mfr's instructions.)

The rebuilder is responsible for it only so far as improper mat'ls/methods were knowingly used or in accordance with written warranty. (Fraudulent or improper mat'ls/methods have no time limit within the recommended TBO.)

The origninal mfr'r is repsonsible for it as far as original design and operational/maintenance instructions. Their culpability diminishes when aftermarket parts are utilized and/or extended operations are undertaken.

I am not a lawyer in any state, and this opinion is worth what you paid for it.

[MoonlightVFR]

I would like to see a picture of the TOP of piston.


What was the condition of the combustion chamber ? Gouging from broken ring pieces?

No damage to the valves/valve seats is a real mystery

Were these ovesize pistons installed at overhaul or standard size.



regards

[Brad Brady]

I would like to see a picture of the TOP of piston.


What was the condition of the combustion chamber ? Gouging from broken ring pieces?

No damage to the valves/valve seats is a real mystery

Were these ovesize pistons installed at overhaul or standard size.



regards

Moonlight,

The top of the piston just showed carbon, not the type of damage you might expect. No gouging on the cylinder walls, The only thing I can think of is that the ring broke and passed through the hole in the top of the piston small enough to do no damage to the valve and seat......although I haven't taken the valve out, it's just that the compression check didn't show any thing getting by the valve!?? I don't have time to take the cylinders down now. Just shipping the crank and seeing if it is salvageable.....The pistons in 1975 were new, standard size....The cylinders were chromed by Harrison in 1973? ish....The old style chrome, with cast iron rings. The more I dig into this the greater the mystery

Regards

[HA]

Brad I'm sure you've looked in the mags already, but that sure looks like a crossfiring mag to me, like a couple other guys said too. normally when a ring breaks it just eats up the cylinder wall and you'll see it there, with those chrome jugs you might not even see any damage to the cylinder wall but the piston obviously get killed.

even if you don't find the specific problem, when the engine goes back together you'll have overhauled or IRAN-ed everything and fixed it whatever it was. sometimes the post-mortem isn't clear, where's those CSI guys when you need them anyway...

[Brad Brady]

Brad I'm sure you've looked in the mags already, but that sure looks like a crossfiring mag to me, like a couple other guys said too. normally when a ring breaks it just eats up the cylinder wall and you'll see it there, with those chrome jugs you might not even see any damage to the cylinder wall but the piston obviously get killed.

even if you don't find the specific problem, when the engine goes back together you'll have overhauled or IRAN-ed everything and fixed it whatever it was. sometimes the post-mortem isn't clear, where's those CSI guys when you need them anyway...

Boy the CSI guys would be good right now.....Crossfiring isn't an option ......it didn't happen...But we have chrome cylinders and the pistion was absolute crap......says a lot.....