ZRP Forged Pistons for BMW 1.8L M42 84.00mm 8.8:1

The BMW 1.8L M40 / M42 pistons are developed for a moderate to high level of preparation, mainly for street or club racing cars that want to develop their engine for high mileage and/or street use. Designed by ZRP engineers and manufactured in Germany from 4032 (T6) high-silicon, low-expansion alloy. This allows the engine builder to use a smaller piston-to-cylinder clearance, which results in better sealing. This minimizes knocking noise during cold starts, common in engines using forged pistons, providing quiet operation and low oil consumption. We have chosen a full round skirt design with a bottom reinforcement band, with oversized and deeper valve cavities to allow the use of high-lift camshaft profiles. They have offset pins for quiet operation and the piston pins are made of 9310 alloy. Other features include anti-detonation grooves to protect the first segments, a gas pressure accumulator groove for better segment sealing and vibration relief. Premium Japanese quality 1.00mm x 1.20mm x 2.80mm ring package included. Product Features and Design Anti-detonation grooves for extended life and performance Gas pressure accumulator groove in the second ring land for extended life. Horizontal grooves in the pin bore designed to allow oil between the piston pin and the pin bore area. CNC precision machined ring grooves 4032-T6 high-silicon/low-expansion alloy Polished pin bores Clip cuts on the intake side edge Full round skirt design with bottom reinforcement band for high HP/Boost applications Valve cavities designed to allow oversized valves and high-lift camshafts Pistons designed to optimize compression for extended engine life and increased horsepower potential Optional coatings offered on request "Blast Off Bronze" thermal barrier coating "Stealth Black" molybdenum side skirt and undercrown coating