Speedfreak
08-21-2008, 02:14 PM
It's hard to tell from the pictures. I can't tell, if all that damage is from a shit load off beating from the valve or if that's melted alum from pre-ignition. Maybe it's obvious in person. I have only seen stock valves fail when a piston hit them from a broken timing belt or whatever and there usually isn't that wide spread of damage even with a broken valve in there, but usually when a timing belt breaks, the motor stops running pretty quick versus Halon's that might have kept running longer with the other 3 cylinders still fine.
My reasons for thinking pre-ignition was the hole in the center of the piston, which is a sign of it. What looks like melted alum all over the piston, head and spark plug, which can be pre-ign, but maybe it's just beat up metal and not melted. A melted valve that fell off, which can be from pre-ign. And I was thinking that maybe the pre-ign started and first thing to start melting was the spark plug, which caused the tach to start going wierd once the electrode melted to the ground strap, then things keep heating up and the valve and/or the piston failed soon after.
Regardless, I would get the fuel injectors tested before putting them in a new motor.
Pre-ignition and detonation are two different things. Often them come hand in hand though with bad detonation causing pre-ignition to occur. But you can have a pre-ignition failure caused by something else.
Ditto^^.
That's why I just said it could just be from things being beaten up. But pre-ignition has a specific look, and the look of that beat up metal is close.
Brandon, did you ever have any overheating issues? And if so did you ever accidentally go WOT during any overheating episodes?
My reasons for thinking pre-ignition was the hole in the center of the piston, which is a sign of it. What looks like melted alum all over the piston, head and spark plug, which can be pre-ign, but maybe it's just beat up metal and not melted. A melted valve that fell off, which can be from pre-ign. And I was thinking that maybe the pre-ign started and first thing to start melting was the spark plug, which caused the tach to start going wierd once the electrode melted to the ground strap, then things keep heating up and the valve and/or the piston failed soon after.
Regardless, I would get the fuel injectors tested before putting them in a new motor.
Pre-ignition and detonation are two different things. Often them come hand in hand though with bad detonation causing pre-ignition to occur. But you can have a pre-ignition failure caused by something else.
Ditto^^.
That's why I just said it could just be from things being beaten up. But pre-ignition has a specific look, and the look of that beat up metal is close.
Brandon, did you ever have any overheating issues? And if so did you ever accidentally go WOT during any overheating episodes?