I bought the 05 Sunfire in March of 2012. It was in horrible shape. Timing tensioner went out (naturally) and the vehicle had 65k miles on it. Picked it up for $400. Valves were @!#$, pistons were damaged, and even one of the pistons had been hit by valves so much, that the rod bearing and the crank were just so far gone (I'm talking a difference of over 0.600"). After researching a ton about the L61, I was game for a full build. Month by month parts were coming. Eagle H beams, Weisco hi-comp pistons, Eagle crank, custom girdle, stage 2 Comp Cams, dual Ferrera valves, and more. Put about $1400 in machining alone. My goal was to push the maximum compression I could for the stage 2 cams. Shaved the head, decked the block, ported and polished the head. Sure enough, I was approaching a final build price of nearly $8k. And slowly I was putting everything back together (only because I was checking every single clearance and gap to make sure they were perfect). When I finally mated the L61 to the Getrag, I was proud (enough that it's the picture on my bank card, haha). The following week, I reinstalled everything. Hooked up the Modis to watch my O2 readings and for any misfires (of course I primed the oil system and used engine break in lube). Fired her up and I had the biggest grin for a little while. Had the front end jacked up while I was breaking in the motor. Everything was going great. But then, I started getting a misfire for cylinder #4. Shut her down and pulled the plugs. Everything looked fine, so it wasn't blow by. Cleaned the plugs to make sure. Started her back up and I was still getting a misfire. After a total run time of an hour, she was getting hard to crank. Something was up. Air was popping through the intake. I knew what that meant; timing issue. Pulled the valve cover and there was the culprit. The tangs on the new exhaust cam broke. Pulled the head and the exhaust valves in cylinder 4 were tapping the piston barely. So I rip the block apart while still mounted in the car. Everything was still perfect that I could see (excluding a timing issue, which I'll mention in a little). Popped out the pistons to check the rod bearings, they were wearing in well. Just what I wanted to see. Go to put the pistons back in and the ring compressor broke on me (during cylinder 2) and the rings caught the sleeve and damaged the piston sure enough. Plus, the chain for the balance shafts and water pump got bound up (was probably the culprit of the whole mess). Guides got broke, chain was messed up, dug into the block a little, and the crank gears bound on the woodruff key. Contacted Cloyes and got new timing kits, ordered the pistons, and got everything taken care of. However, several months went by before I finally cancelled my order for the pistons (was getting a back order response). So she's just sitting and sitting. Finally, after 16 months, I gave in. I ripped all my gold plated wiring, terminals, relays, short shifter knob (for my Z31), and everything else I wanted to keep. About 12 hours ago was the last time I saw her. She weighed 2200 with no fluids (I also gutted it out). It is a bitter moment, but I didn't have the time to deal with her (or the room now that I'm living elsewhere). My total cost in parts and machining alone was close to $11500. It's a lot of money to throw away, but it's one less thing for me to worry about. Between calculations for the compression, machining, cams, stock fuel system, and stock ecu, that I was probably making close to 172 hp at the wheels (give or take a few). All she needed was a full turbo setup, standalone ecu, upgraded fuel system, and she would have destroyed the transmission on the first run.
However, I did keep the Eagle H-Beams. They were well maintained and don't have any rust surprising after sitting so long. I'll be throwing them up on Ebay for probably $175-200 for the set. If you're interested in the Eagle H-Beam Rods, send me an email at firstname.lastname@example.org.
Sorry about the bad luck, but to be blunt i think you had messed up the timing chain install. These engines are VERY tricky to get the timing and all just right or disaster will strike.
And I would have suggested that you go with low compression pistons, they're much more boost friendly. And I seriously doubt you would have destroyed the transmission on the first run out. There are many of us with 400-500+ horsepower cars running stock trannys.
Currently #4 in Ecotec Forced Induction horsepower ratings. 505.8 WHP 414WTQ!!!
Currently 3rd quickest Ecotec on the .org - 10.949 @ 131.50 MPH!!!