Description

Low drag 1275 piston standard size 2.780 plus 40 thou oversize(Rings included). This piston has a possible compression ratio of 10.3:1 as fitted to Cooper RSP 1990.Engine then becomes 1310cc Current pistons differ from the 60s originals and now have a “low drag” slipper skirt design and a shorter lighter 20.6mm wrist pin. Wrist pin height is 1.5276″ to crown with a top dish of 8cc. Performance is enhanced by the use of 3mm oil rings and the smaller drain slot behind this ring decreases the risk of breakage and 2 of 1.5 mm compression rings. Crown depth to first ring is about 10mm. Rings are R41570-40. AE Hepolite is now owned by Federal Mogul and trademarked “Nural” .Now Nural stamped 87-524111-00 Sold singly,4 per engine required–equivalent type was Rover piston TAM2050 stamped AE21963 as fitted to 1990 Cooper 1275 engines.