The Processes Behind the LS7 Engine Explored

  The LS7 is a 7.0 L, 427.8 cu in, engine based on the Gen IV engine architecture. The engine block is changed, with sleeved pistons and a larger 4.125 in bore and longer 4.00 in stroke than the LS2. The small block's 4.4 in bore spacing is retained, requiring pressed in cylinder liners. The crankshaft and main bearing caps are forged steel for durability, the connecting rods are forged titanium, and the pistons are hypereutectic. The two valve arrangement is retained, though the titanium intake valves by Del West have grown to 2.20 in and sodium filled exhaust valves are up to 1.61 in.

  Peak output of the LS7 is 505 horsepower at 6300 rpm and 470 ft•lb of torque at 4800 rpm with a 7000 rpm redline setting a new record for a production overhead valve pushrod engine. During GM's reliability testing of this LS7 engine in its prototype phase, the LS7 was remarked to have been repeatedly tested to be 8000 rpm capable, although power was not made at that rpm level, due to the constraints of the camshaft's profile and the intake manifold ability to flow required air at that engine speed.

  The LS7 is hand built by the General Motors Performance Build Center in Wixom, Michigan. Most of these engines are installed in the Z06, but some are also sold to individuals by GM as a LS7 crate engine.

  After an extensive engineering process over several years, Holden Special Vehicles fitted the LS7 to a special edition model, the W427. The HSV tuned LS7 engine produces 503 horsepower and 470 ft. lbs of torque, making it the most powerful car ever built in Australia. The W427 was unveiled at the Melbourne International Motor Show on the 29th February, 2008 and went on sale in August 2008.