Hastings, 3-7/8" chr/moly piston ring set. STD

Replacement for 99-06 Twin Cam models that are equipped with the 95" (1550cc) 3-7/8" OEM big bore kit. Also fits 07-17 Twin Cam 103" (1690cc) engine.

Std cyl. bore: 3.875" (98.425mm).

1st ring: 1.5mm.

2nd ring: 1.5mm.

oil ring: 2.5mm.

Tech tip: Piston grooves vs piston rings.

It's not difficult to determine if a Hastings piston ring set will fit a certain piston. You should measure the height of the piston groove in the piston itself. The 2 top grooves will be for compression rings, the lower groove will be for the oil ring. In most cases Hastings oil rings are of the low tension 3-piece flex vent type. Ring heights are listed for reference.

Tech tip: Piston oversizes.

For each oversize cylinder diameter will increase with .010" (0.254mm). The standard bore of the cylinder is listed for reference.

(Information provided by Hastings Manufacturing Company, Inc.)