BBC makes 1,200+ hp on stock cast internal rotating assembly
In this month's (Oct 2014) issue of Car Craft, they tried to blow up a stock Chevy big block (CBB) by adding twin turbos. They bought a motor out of a junkyard 1 ton pickup and put new rings in the short block. It did have 4 bolt mains, but otherwise it was cast crank, cast rods, and cast pistons. The stock 8:1 compression was boost friendly.
To make some power before blowing it up, they added an intake, 850 Holley carb, mild cam and aluminum heads. The cam hurt them on power, with a street friendly 226/234 duration. Lift was restricted to .529/.525 because the stock pistons didn't allow much clearance, also holding down their power numbers.
With no boost, they got 442 hp / 447 torque, with performance held back by the low compression ratio. With the mild cam, torque was always higher than hp at every level of boost.
With twin 76mm turbos hp/ torque:
7 psi: 607 / 667
11.6 psi: 730 hp
14 psi: 814 hp
19.2 psi: 958 hp / 1,032 torque
At this point, they switched to race fuel and cooled inlet temps to a low 61 degrees before adding more boost, eventually reaching 29 psi and producing 1,237 hp / 1,322 torque.
They tried adding more boost to break the engine, but their fuel pumps were maxed out. So they never did blow it up, despite running cast internals and reaching 29 psi of boost and making 1,200+ hp. These numbers wouldn't be shocking if they used one of the factory high performance engines with 4 bolt main and forged internals, but I'm surprised the cast rotating assembly held up to this punishment.