Icon FHR Pistons IC9958-STD Fits BBC 427 Dome 28.2cc Bore 4.250

Icon's FHR (Formed Head Relief) pistons deliver quality on a budget. FHR pistons have valve reliefs that are formed into the piston as the forging blank is pressed into the die. Many of the FHR dome pistons feature a solid dome. This gives engine builders the flexibility to machine the dome to their desired compression ratio. FHR pistons are 11% silicon which means they can be installed with tighter piston to wall clearance. In addition, the use of 4032 aluminum decreases the friction created during engine operation, this results in extended piston life and reduced wear.

Mini grooves allow an overheated pistons to transfer heat to the wall

Skirts machined by UEM's unique in house built cnc machines

Die formed relief valves

Accumulator groove to help eliminate flutter and maximize ring seal

Wrist pins and spiral lock included

5/64 x 5/64 x 3/16 not included

Compression Ratio 96.5cc 12.4:1, 105cc 11.3:1, 119cc 9.8:1

Advertised piston weight 706 grams, 141-gram wrist pin

OE Deck Height 9.800"

Note: Standard bore size is 4.250

Note: Centered Pin. Closed chamber design