Moonshine
11-23-2013, 08:35 PM
OK, here's a pop quiz for our assortment of engineers, mechanics, amateur gearheads, and hotrodders. The subject is multi-cylinder, water cooled, 4 stroke, fuel injected, supercharged engines, something we all have some interest in. The test question is based on the following -
3983398439853986
For clarification;
Photo 1 shows some significant scoring on one side of a cylinder wall (the exhaust side, if that helps you). The other side of that cylinder looks pristine, as do all of the other cylinders. Incidentally, the pictured scoring is significant enough to cause a 30 PSI loss on compression in said cylinder.
Photo 2 shows the piston that came out of that cylinder. As noted, the other side of the piston looks fine. You will note that the scoring is all below the rings, the rings themselves do not appear to be seized, and there's no evidence of damage above the rings.
Photo 3 shows some scoring on the crankshaft journal for the same cylinder. Again, no damage is noted on the journals for any other cylinders.
The last photo shows similar scoring on the cam lobes for the same cylinder. Again, no damage to the cam on any other cylinders.
The test question is two part - 1. What would cause the noted damage?, and 2. Why is the damage limited to one cylinder only?
I'm open to guesses, speculation, or well reasoned thoughts. At present, I do not know the answer to the question(s). For the time being, I will not identify the application or manufacturer, as I am still working with the manufacturer of the engine and do not want to compromise any possibility of them assisting me with repairs. Their engineers will be looking at photos in the coming days/weeks, so I do expect to learn what they think caused this, but I'm also interested in the collective knowledge of TALON.
3983398439853986
For clarification;
Photo 1 shows some significant scoring on one side of a cylinder wall (the exhaust side, if that helps you). The other side of that cylinder looks pristine, as do all of the other cylinders. Incidentally, the pictured scoring is significant enough to cause a 30 PSI loss on compression in said cylinder.
Photo 2 shows the piston that came out of that cylinder. As noted, the other side of the piston looks fine. You will note that the scoring is all below the rings, the rings themselves do not appear to be seized, and there's no evidence of damage above the rings.
Photo 3 shows some scoring on the crankshaft journal for the same cylinder. Again, no damage is noted on the journals for any other cylinders.
The last photo shows similar scoring on the cam lobes for the same cylinder. Again, no damage to the cam on any other cylinders.
The test question is two part - 1. What would cause the noted damage?, and 2. Why is the damage limited to one cylinder only?
I'm open to guesses, speculation, or well reasoned thoughts. At present, I do not know the answer to the question(s). For the time being, I will not identify the application or manufacturer, as I am still working with the manufacturer of the engine and do not want to compromise any possibility of them assisting me with repairs. Their engineers will be looking at photos in the coming days/weeks, so I do expect to learn what they think caused this, but I'm also interested in the collective knowledge of TALON.