Porsche V8 engines

Porsche's first V8 engine is the Type M28, which debuted in the Porsche 928 in 1977. It is an all-alloy design with a linerless block cast of a hypereutectic aluminum-silicon alloy whose bore surfaces are created by etching the aluminum back, exposing the precipitated silicon using the Alusil process. The M28 was introduced with a single overhead camshaft per cylinder bank operating two valves per cylinder, and bore × stroke measurements of , giving a displacement of . A compression ratio of just 8.5:1 allows it to use regular 91-octane gasoline. This early version makes at a 5,500 rpm, which delivered a top speed of . Torque is at 3,600 rpm. The 928S was released in 1980 with a slightly enlarged version of the M28. Bore was increased to , bringing total displacement up to . Compression was raised to 10.0:1, which required the use of premium gasoline (compression in US models was 9.0:1). Power output rose to , and top speed was above . Another increase of the compression ratio to 10.4:1 in 1984 and a switch to electronic fuel injection boosted power to . Multi-valve, DOHC redesign The M28 received a substantial redesign in 1985 with the adoption of redesigned cylinder heads with four valves per cylinder and two overhead camshafts per cylinder bank. The bore was increased again, this time to , giving a new displacement of . The European version with its new catalytic conversion emissions control system and 10.1:1 compression ratio produced . In 1987 the 928 S4 arrived with a 5-litre M28 tuned for premium fuel that produced . In 1989 a 5-litre 928 GT was released, whose engine made , thanks to tighter valve timing. In 1992, Porsche released the 928 GTS, with the largest M28 of all. Bore remained at 100 mm, but the stroke was lengthened to , for a displacement of . With compression back up at 10.4:1, this engine produced . Production of the M28 V8 engine family ended in 1995, with the end of the 928 model. Applications • Porsche 928 ==Type 9M0==

Porsche developed a new 90° V8 engine for use in Indycar racing in 1988. Called the Type 9M0, it had bore and stroke measures of respectively, and displaced . The 9M0 used a single turbocharger in compliance with Indycar rules. Development was led by Hans Mezger. On methanol fuel, the engine was capable of producing at 11,200 rpm, and at 8,500 rpm. Applications • Porsche 2708 • March 88C • March 89P • March 90P ==Type M48==

The Type M48 V8 debuted in the Cayenne S SUV in 2003. Like the M28, the first version of the M48 had a nominal displacement of 4.5-litres, but its internal dimensions were different from its predecessor. Bore × stroke are , for a true displacement of . The Type M48 engine was offered in both naturally-aspirated (NA) and forced induction forms, with an unboosted version making , and an engine with twin turbochargers making from the same displacement. In 2006, Porsche revisited the turbocharged engine and boosted its output to for use in the new Cayenne Turbo S. The M48 line was updated in 2007. Gasoline direct injection arrived as Porsche phased the system in across their product line. Cylinder bores were increased to , bringing displacement to . The Turbo engine received new turbochargers with larger radial turbines. With these changes, the unboosted engine in the Cayenne S had an output of , while the turbo engine now made of power. The M48 was also offered in the Panamera released in 2009. In the sedan, the naturally-aspirated engine produced and of torque, while the twin-turbo 4.8-litre made and . Extensive use of lightweight alloys and design changes reduced engine mass by several kilograms. Less than one year later, these versions were introduced to the Cayenne lineup as well. Even higher-power versions for the sports models of the Panamera and Cayenne were developed. The naturally-aspirated engine made in the Panamera GTS, and in the Cayenne GTS. The turbocharged engine in the Cayenne Turbo delivered , the one in the Panamera Turbo S , and the version in the Cayenne Turbo S peaked at . Daytona Prototype engine A Daytona Prototype car built by the Spirit of Daytona team was to use a Fabcar FDSC/03 chassis and a 5.0-litre V8 derived from the engine used in the Porsche Cayenne, making it likely to have been some type of M48 engine. The 5.0-litre engine is a special version built by the team, and did not carry Porsche badging. Applications • Porsche Cayenne • Porsche Panamera • Fabcar FDSC/03 ==Type MR6==

The MR6 engine was designed by Porsche with input from Penske Racing. Bore and stroke are respectively, for a total displacement of . The engine uses a flat-plane crankshaft. The MR6 was used in the Porsche RS Spyder, where the engine drove the rear wheels through a six-speed electro-pneumatic sequential gearbox. When introduced in 2005 the engine produced . In 2007, the car was renamed the Porsche RS Spyder Evo, and engine output was up to . In mid-2008 the engine received direct fuel injection. Peak power was unchanged from 2007, and fell to in 2009-spec with air restrictor limitations. Applications • Porsche RS Spyder ==Type M18==

Porsche's next V8 was the Type M18, which went into production in 2013 and was used in the 918 Spyder. The M18 is a naturally aspirated V8 engine built on the same architecture as the MR6 used in the RS Spyder Le Mans Prototype racing car. The M18 has a flat-plane crankshaft with 180 degrees of offset between crank throws. In the 918 Spyder, the engine is part of a gas/electric hybrid drive system. In developing the M18 from the MR6, the bore remained at 95 mm, while the stroke was increased to 81 mm for . The engine runs to 9,200 rpm. The M18 uses direct fuel injection with centrally located solenoid injectors that deliver fuel at pressures up to . Features such as titanium connecting rods and thin-walled, low-pressure castings of the crankcase and cylinder heads keep weight to a minimum. The M18 delivers at 8,700 rpm and of torque at 6,700 rpm. This is supplemented by two electric motors delivering an additional total: a electric motor drives the rear wheels in parallel with the engine and also serves as the main generator, and a motor drives the front wheels. In 2011, a more highly tuned M18 was used in the 918 Spyder RSR that offered at 10,300 rpm. At 132 hp/litre displacement, it had the highest specific power of any contemporary street-legal naturally-aspirated engine, and was also the lightest naturally-aspirated production V8 engine, weighing only . The M18 has a distinct sound, partly attributable to its flat-plane crankshaft, but additionally due to it having a "top pipes" exhaust system. The M18 is a "Hot Side Inside" (HSI) design, with the intake ports on the cylinder heads facing outwards, and the exhaust ports mounted inwards, facing the other side of the cylinder block vee. The "top pipes" mean that the balance of the very short exhaust system is also mounted above the engine, exiting through the engine deck lid. Advantages of this arrangement include reduced weight, improved aerodynamics, and reduced back pressure. It also allows Porsche to more easily manage the heat output from the V8, and keep it from affecting the performance of the battery pack. The M18 influenced the development of the 9RD engine used in the Porsche 963. Applications • Porsche 918 Spyder ==Type EA825 TT==

The Type EA825 V8 is the result of a collaboration between Porsche and Audi. It was the successor to the EA824, which was an Audi design and a further development of their earlier 4.2 TFSI V8. The EA825 draws on the design of the Volkswagen-Audi Group's EA839 90 degree V6. Production took place at Porsche's engine facility in Zuffenhausen. Bore and stroke are identical at , yielding an engine size of . The linerless cylinder block is of a eutectic aluminum-silicon alloy, and the bores have an iron coating deposited onto their surfaces. Forced induction is provided by two turbochargers mounted inside the vee of the block in a "Hot vee" configuration. The EA825 TT was offered as a petrol engine option in both the second generation Panamera and third generation Cayenne in 2017. It became available as part of a hybrid petrol/electric powertrain in the Panamera in 2017, and in the Cayenne in 2019. ==Type 9RD==

For the 963 Le Mans Daytona hybrid LMDh class car, Porsche developed another V8 engine called the Type 9RD. Its most recent antecedent was the M18 used in the Porsche 918 Spyder, with which it shared about 80% of its components, but the engine's lineage goes all the way back to the MR6. Like the M18, the 9RD displaces 4.6-litres, and is part of a hybrid powertrain that produces total. The engine weighs . Unlike the naturally aspirated M18, the 9RD has a low-pressure twin turbo system by Van der Lee mounted inside the 90-degree engine's cylinder bank vee. Applications • Porsche 963 ==See also==