Nicasil is abbreviation for Nickel Silicon Carbide. Silicon carbide is quite hard ceramic (even harder than the steel) which can be dissolved in nickel. Then, the nickel solution can be electroplated onto the aluminum cylinder bore. The piston rings then rub off the exposed nickel leaving behind a very hard layer of silicon carbide to save the aluminum piston from direct contact with the aluminum cylinder. With the help of this setup, the engine tolerances can be made much tighter to get better performance. After the cylinder is re – bored then it must be re – plated but Nicasil is extremely durable therefore, reducing the cylinder’s need to be reworked as often as an iron or chrome cylinder.
Nicasil was first introduced by Mahle in 1967 though it was initially developed to allow rotary engine apex seals (Mercedes C111 and NSU Ro 80) to work directly against the aluminium housing. This coating helped aluminum cylinders and pistons to work directly against each other with low wear and tear and low friction. Unlike the other methods, including cast – Iron cylinder liners, Nicasil allowed very large cylinder bores with tight tolerances have better performance and thus allowed existing engine designs to be expand easily. The aluminum cylinders also gave much greater heat conductivity than cast iron liners, an important trait of a high – output engine. The coating was further harnessed by US Chrome Corporation in the United States in the early 1990s (under the name of "Nicom" for trade), to use instead of hard – chrome plated cylinder bores for Kohler Engines, Mercury Marine Racing and as a repair replacement for factory – chromed automotive V8 liners / bores, ATVs, watercraft, snowmobiles and dirt bikes.
Porsche started using this in the year of 1970 for their 917 race car, and later in 1973 for 911 RS. Porsche also started using it on its production cars but for a short time it switched to Alusil for cost savings for their base 911. Nicasil cylinders were always in use for the 911 Turbo and RS models and still are in use for today’s 911s. Nicasil coated aluminium cylinders allowed Porsche to build air - cooled engines which had the highest specific output of any engine during those times.
Nicasil become very popular during the 1990s. It was used by many companies including the European Giants – Audi, BMW, Ferrari, Jaguar Cars and also by Moto Guzzi in their new engine families. However, due to the presence of sulfur in much of the world's low – quality gasoline caused few Nicasil cylinders to break down over time which caused costly engine failures.