Updates are going slowly right now.
I am still in need of an answer for the block failure but I am thinking that I may never get one as sometimes it is near impossible to discern the originator in a catastrophic failure like this. There is missing info that I may never know, like just how much power/torque this engine was making just before it went pop. I was a week or so from throwing the truck on the dyno unfortunately. The best I can do is throw it on the dyno once it's rebuilt which might give me a rough idea but that is about all. Was the engine from a vehicle that died a horrible death in a head on accident? How had the previous owner treated it? Was it dropped in shipping? Etc...
Concerning how much the juice was turned up on this motor and whether power was a factor... The injector pump has a 2mm larger then stock pump piston (12mm vs. 10mm 44% bigger), the injectors that I am running are capable of flowing 103% more fuel then the stock nozzles and supporting 210+HP and the boost was running at 22 psi (starting at 1600rpm) vs. 12-14 psi max stock. So yes it was turned up just a bit. A seat of the pants guess is torque in the neighborhood of 300-350 ft/lbs. All that said I have been told that it "should" have been fine with my modifications.
I now have another block (this one will get throughly checked out) and one of the things that I am going to look at if the possibility of core shift in the old block that might have made that side thinner then it should have been. I have also, since my last posts, finished off the block with a hammer and I have to say it didn't take much effort (I did it at the bay area GTG). At the rear of the block the casting was held together by just over a 1/2 inch of material and the front was only slightly better with only 2 inches still intact. The whole block was shattered. Unfortunately it didn't tell my semi-trained eye a whole bunch more. Then I happened to notice the most telling clue yet, number 3 main web was broken through the main bolt hole on that side of the block and the main cap was considerably fretted on the outside of the crack, which I think, tells me that the block had been broken for a while (hundreds or thousands of miles?) before I caught it, ie. the #2 main cap departed the block.
Pictures of the now finished block and below that the fretting visible on the #3 main cap parting line.
Sorry about the blurriness of this first picture.
Matching #3 Cap fretting.
Just the cap.
Close up
#3 block fretting. Just the block.
Maybe this gives someone more insight that they'd like to share.
I am working on the main girdle design for the new block. I am getting it all sorted and once I have the design finalized then I will have some 1/2" plate waterjet cut and surfaced. Is a girdle overkill? Most likely, but I am not going to rebuild this engine without making sure that this doesn't happen again. One way or another the new motor is going to be stronger then the old and I (and my old engine machine shop instructor) think the girdle will help to solidify the bottom of the block, at least helping the strength and minimizing flexing.
The head is currently being rebuilt at Frank's TDI and while getting rebuilt it is also getting the intake and exhaust ports cleaned up by Frank as well. A little porting can't hurt, especially on the tiny exhaust ports.
Thanx again for all the input,
Jaysin