liquid at idle, which improves conductivity and draws heat away from the valve face and valve guide towards the stem to be cooled by the engine oil circulating in this area. The camshaft-driven direct injection systems pressurizes the fuel to at idle, and up to at wide-open throttle. The "Gen II" block is similar to the 2.4 L and also features VVT technology. The Gen II block was developed using data from racing programs and computer simulations. The bore walls and bulkheads were strengthened with a weight increase of . The coolant jackets were expanded to improve heat transfer, resulting in a coolant capacity increase of 0.5 liters. In December 2008, GM released a Turbo Upgrade Kit for the LNF engine which increases horsepower to and torque to up to , depending on the model. The kit retailed for $650 and includes remapped engine calibration and upgraded 3 MAP sensors. The kit is covered by the cars' existing GM warranties. Boost pressure was increased from 18psi (1.24 bar) to 21psi (1.44 bar). Unique LNF features include: a twin-scroll turbocharger cam-driven high-pressure gasoline direct injection fuel system dual camshaft continuously variable valve timing sodium-filled stainless steel Inconel exhaust valves low-friction cast aluminum pistons with oil squirters forged steel crankshaft forged steel connecting rods cast stainless steel exhaust manifold foam cast gen2 block bosch injectors 0 261 500 055 or slightly larger 0 261 500 089 injectors in 2010 models This engine is used in: 2.0 LDK (A20NHT Opel) An updated variant of the LNF (also with 9.2:1 compression ratio) was released in 2008, meeting the Euro 5 emission standard. This engine is also known as A20NHT by GM Powertrain Europe. Unique LDK features include: a twin-scroll turbocharger cam-driven high-pressure gasoline direct injection fuel system dual camshaft continuously variable valve timing sodium-filled stainless steel Inconel exhaust valves low-friction cast aluminum pistons with oil squirters forged steel crankshaft cast stainless steel exhaust manifold foam cast gen2 block bosch injectors 0 261 500 055 This engine is used in: LHU (A20NFT Opel) LHU adds E85 flex-fuel capability to the LDK. This engine is also known as A20NFT by GM Powertrain Europe. Maximum engine speed is listed at 6350 rpm. Unique LHU features include: a twin-scroll turbocharger cam-driven high-pressure gasoline direct injection fuel system dual camshaft continuously variable valve timing sodium-filled stainless steel Inconel exhaust valves low-friction cast aluminum pistons with oil squirters forged steel