JE Nitrous Series pistons are similar to the Big Block Nitrous Series JE Dome pistons, vertical and lateral gas ports have been incorporated to optimize top ring seal and reduce friction. Ring grooves are machined to accept JE Pro Seal series J860 “HNS” Hardened Nitrous Series rings with .043 back-cut top ring, 1/16 taper face second ring and 3/16 oil ring. Compression height figured using 9.800? deck height with zero deck clearance. Fits most open chamber cylinder heads. Part Number 258199 is designed for a decked block.

Includes:

Pin #990-2930-18-51S (174g)

Double spiro locks (#990-042-CS)

Vertical and Lateral gas ports

Contact reduction grooves

Compression Ratio:

110cc 16.3:1

118cc 14.9:1

124cc 14.0:1