How Bad Is It

[sheriong]

About a month back, I decided to make a quick pass and get around a truck to enter the freeway, I heard a snap and then some knocking, so assumed that I had finally destroyed the engine because the car was turbocharged about a year and half ago, but never got around to having a stand alone system installed, even though I had an AEM box at home and was using a chip.
However, had the car towed and finally got the engine out with the help of the great articles here. I was expecting a broken rod or something, but instead found a cracked #1 cylinder and a piece of the head broken off on the left side, would this be the result of a cooling problem? I certainly will have to replace that cylinder and assuming that the broken part of the head can be removed also, and have the others looked at. As I noted, the pistons are all in place, so no broken rods, however, on the left side, the cylinders easily came off, is that normal? I do not want to rebore the engine, but would it make sense to check for spun bearings and change those, more importantly, does opening the case require machine work if no obvious damage or are there concerns about future performance? Plan to take the heads to a machine shop and get updatd. What can be done about the pistons and cylinders, assuing, if no other damage, they can be cleaned and reused.
Would appreciate some feedback on possible causes, could it relate to my turbocharging of the car? I do not think that Iwas driving fast and actually have been babying the car knowing that the tuning was questionable. If I can do the required work, will certainly go for some of those while you are in there fixes.
Here are some pics of the damage and condition of the pistons.




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Sheriong

[ischmitz]

I am not an expert but let me ask this: Did you just get a turbocharging system installed or was there anything else done to the engine at the time?

FYI, the stock compression of a NA 3.6 is 11.3:1. This is enough to require twin-plugging and adaptive knock control. In contrast the Turbo engine has a compression ratio of 7:1. The lower compression is to accommodate the additional cylinder charge introduced when under boost without detonation and knocking.

I don't see how you could ever control knocking when under boost in a NA 3.6. It doesn't matter how fast you where going. All that matters is how much boost the engine saw when you opened the throttle. From the split barrel it seems there was some serious detonation going on.

Ingo

[sheriong]

When the car was set up, the intention was to go a stand alone system, but that was delayed as I was looking at some options, finally bought the AEM box but now was waiting to get every done. Should have just left the car in the garage. The car had A/F meter, which seemed to be giving good readings plus a RR FPR, and I have never pushed it to 6 lbs of boost even though it has an intercooler. Anyhow, will need to get her back together eventually.
Thanks