Nikasil
Nikasil is a trademarked electrodeposited oleophilic nickel matrix Silicon Carbide coating for engine components, mainly piston engine cylinder liners. It was introduced by Mahle in 1967, initially developed to allow rotary engine apex seals (NSU Ro80 and C111) to work directly against the aluminum housing. This coating allowed aluminium cylinders and pistons to work directly against each other with low wear and friction. Unlike other methods, including cast iron cylinder liners, Nikasil allowed very large cylinder bores with tight tolerances and thus allowed existing engine designs to be expanded easily, the aluminium cylinders also gave a much better heat conductivity than cast iron liners which is an important factor for a high output engine. The coating was further developed by US Chrome Corporation in the USA in the early 1990s (under the trade name of "Nicom") as a replacement for hard-chrome plated cylinder bores for Mecury Marine Racing, Kohler Engines, and as a repair replacement for factory-chromed snowmobiles, dirt bikes, ATVs, watercraft and automotive V8 liners/bores.
Porsche started using this on the 1970 917 race car, and later on the 1973 911 RS. Porsche also used it on production cars, but for a short time switched to Alusil due to cost savings for their base 911. Nikasil cylinders were always used for the 911 Turbo and RS models. Nikasil coated aluminum cylinders allowed Porsche to build air-cooled engines that had the highest specific output of any engine of their time. Nikasil is still used in today's 911s with great success.
Nikasil was very popular in the 1990s. It was used by companies such as BMW, Ferrari and Jaguar Cars in their new engine families. However, the sulfur found in much of the world's low quality gasoline caused some Nikasil cylinders to break down over time [1], causing costly engine failures.
Nikasil or similar coatings under other trademarks are also still widely used in racing engines, including those used in Formula One and ChampCar. Suzuki currently uses a race-proven nickel phosphorus-silicon-carbide proprietary coating trademarked SCEM (Suzuki Composite Electro-chemical Material) to maximize cylinder size and improve heat dissipation, e.g., on the engine of the Suzuki_TL1000S and Suzuki DL650 V-Strom and Hayabusa motorcycles [1].
Engines using Nikasil include:
- Aprilia RS125 And Aprilia SX/RX 125
- Armstrong MT500 - Rotax engine cylinder lining
- Chevrolet LT5 engine, designed by Lotus and used exclusively in the Corvette ZR-1
- Chevrolet Vega 2.3l, and 2.0l Cosworth fours
- Citroën Visa twin
- Citroën GS birotor wankel engine made by Comotor
- BMW M52 I6, except exports to North America
- BMW M60 V8
- BMW R80GS, as measure to reduce weight over cast-iron lined cylinders
- BMW S1000RR, scheduled for early 2010 release.
- Ferrari F50 V12
- Ford RS200
- Honda RS125R [2] - cylinder lining
- Honda RS250R [3] - cylinder lining
- Honda NSR 150SP
- Honda XR650R
- Jaguar AJ-V8, 1997 - 2000 (XK series VIN range 001036-042775, XJ V8 series VIN 812256-878717) [2]
- KTM LC4
- Lambretta TS1
- Lotus Esprit Turbo 2.2
- Maserati Biturbo 2.0 V6 Engines
- Moto Guzzi 850 T3 and derived engines
- NSU Ro80
- Porsche 912 engine ( engine in 917 car, not to be confused with the Porsche 912 car )
- Porsche 911 1973+ (excluding some 1975-1978 911S)
- Suzuki LTR450
- Suzuki RGV250
- Vespa T5
- Sonex AeroVee Aircraft Engine
References
- ^ "Suzuki V-Strom 650, Sean Alexander, Mar. 21, 2004". www.Motorcycle.org.
- ^ The Jaguar AJ-V8 Engine