HASTINGS Piston Ring Set — 3.498" bore, +0.040" oversize – 78-86 Big Twin, 80, 83-98 Touring, 85-99 Softail, 91-98 Dyna, 82-94 FXR

🔧 Replacement piston ring set that includes top compression rings, second compression rings, and three-piece oil control rings.

Top compression rings are barrel face to aid heat transfer between the piston and cylinder wall and to control combustion gases so the piston can transfer energy to the crankshaft.

Second compression rings are reverse torsional taper face to promote side sealing that prevents oil from being forced under and behind the ring, resulting in better oil economy. The reverse twist ring with a taper-machined ring face duplicates the outer-diameter bottom-side scraping edge of a positive twist torsional ring.

Oil control rings are a three-piece flex vent design; the three-piece design allows rails to be manufactured with a small cross-sectional area for better conformability to the bore and provides uniform pressure through four steel rails and two expanders to assure positive oil control.

Made in the USA.

Please read the instructions furnished with the piston for correct top ring end gap and ring installation, as special attention is required due to the thermal conductivity and design of KB pistons.

Includes enough rings for two pistons. Two rings per groove, except for the rails that use two rail rings per one expander.