I posted yesterday that my truck was DOA on the freeway and that I took my spare block to the machinist. Today I removed the cadaver today and here is what I found. Sorry but I dont have any pics. Holes 1 and 3 have the pistons about halfway down the bore and the pistons have come apart at the wrist pins. The rods are both severed above the bearings. I found 2 studs still intact and holding pieces of the rod along with the nuts. I found one bent with the nut off of the threads and one sheared. There were 2springs in the pan that must have come from inside a couple of lifters. I haven't removed anything but the oil pan yet, but from what I can see there doesn't seem to be any grooving as if a wrist pin were rubbing the cylinder wall. I did see that the oiling holes in the crank seemed to have been elongated and one looked as if it had been hit with a punch.
The events leading up to the failure were pretty straightforward. I was on the beltway in drive and climbed right on up to somewhere around 3,000 rpm and shifted into OD. I dont have a tach but I seriously doubt that I was spinning more than 3500 tops. I have put about 5,000 miles on this motor since it was built last year. (yeah that sucks) I was running a decent piston at 9.25 on stock rods and studs. I have a very mild cam with flat tappet lifters. I dont have a lot of engine experience outside of the bike stuff, so I am wondering about the chain of events that may have caused this to happen. I will be putting together another motor this week and I would really like to avoid doing this again any time soon. Any theories and insight would be much appreciated.
Chris