similarly electro-chemically treated with an Fe-P (Iron and Phosphorus) plating for wear resistance. · Toyota’s first engine using

similarly electro-chemically treated with an Fe-P (Iron and Phosphorus) plating for wear resistance. Toyota’s first engine using MMC technology was used successfully in performance vehicles by Toyota and also by Lotus in the Exige and Elise.23 Toyota found they were able to produce 26.17% more horsepower and 4.65% more torque with the same 1.8 liters of displacement by eliminating the cast iron liners.24 Although all the above mentioned engines are all-aluminum and linerless, that’s where the similarity ends. With Lokasil, blocks are cast using a quasi-monolithic high pressure die casting process where freeze cast sintered cylinder liner preforms, manufactured by Ceram Tec AG,25 are infiltrated with molten under- eutectic (low silicon content) aluminum at 900-1000 bar of pressure. These inserts provide selective reinforcement with a localized high silicon hypereutectic cylinder bore composition and allows the rest of the engine block to be cast from lower silicon content aluminum. The Lokasil process results in reduced cost and greater ease in manufacturing over monolithic low pressure die cast Alusil blocks.26 27 The 911 and 3.4 Cayman S models received Mahle supplied forged pistons with an iron skirt coating called Ferrostan, later replaced by Ferroprint. Boxster base and S models came with cast Kolbenschmidt pistons that utilized their Ferrocoat process for the skirt coatings. The Lokasil process was new for Kolbenschmidt and Porsche was their first OEM customer for blocks cast using this new process. They had their share of production issues initially with Lokasil blocks, with a scrap rate of 35-40% according to Motor-KRITIK. Many required re-working, including sleeving (later leading to slipped-sleeve failures), to keep up with production.28 As the technology progressed, several improved versions of Lokasil were used by Porsche - Lokasil II with the 3.6 in 2002 and Lokasil III29 with the introduction of the M97 engine in 2006, ending in 2008. In the Lokasil I process, the aforementioned freeze-cast liner preforms containing the silicon matrix with particle sizes ranging from 30 to 70 µm are suspended in a synthetic resin bond. The inorganic binder holds the silicon particles in suspension until the under-eutectic aluminum casting alloy (AlSi9Cu3) infiltrates the preform during the casting process. With Lokasil I, preforms contained 5-7% fiber (alumina) and 20% silicon content. However, with Lokasil II, silicon content was increased to 25% and alumina was replaced by an inorganic binder of less than 1%; silicon particle sizes were increased to a maximum size of 120 µm. Porsche to this day remains the only manufacturer to have utilized Kolbenschmidt’s Lokasil, before returning to Alusil with the introduction of the MA1 (also referred to as the 9A1) engine in 2009. Nikasil was retained for the Mezger engine until retired by Porsche, which coincided with the introduction of the 991. In 2016, Porsche announced use of ultra-thin Rotating Single-Wire (RSW) iron lined bores (with coating 22 Metal Matrix Composites in Industry: An Introduction and a Survey, Volume 1. Alexander Evans, Christopher San Marchi, Andreas Mortensen. 23 https://en.wikipedia.org/wiki/Toyota_ZZ_engine#2ZZ-GE 24 Replacing the Cast Iron Liners for Aluminum Engine Cylinder Blocks: A Comparative Assessment of Potential Candidates. John Lenny Jr. 25 New materials, new thinking. Elaine Catton. Automotive Manufacturing Solutions Oct/Nov 2002. 26 The Aluminum Automotive Manual. Version 2011. European Aluminium Association. 27 Limited edition with ATAG engine blocks. Das Profil Newsline. Rheinmetall Group. Jan 2004. 28 Rückrufe, Zuliefererprobleme und Produktionspannen. Wilhelm Hahne. Motor KRITIK. 29 https://www.motor-talk.de/forum/motorschaden-997-t3947119.html?page=5 LN Engineering Technical Library. Copyright ©2019 LN Engineering LLC