4.040" PISTON RINGS, Steel Nitride top ring & Napier 2nd 1.5MM, 1.5MM, 3.00MM also fits: Chevy 350, Ford Windsor, Holden 304 308

DRP PISTON RINGS Fits 4.040" Pistons with 1.5mm rings

Also fits 4.040 bore: Chevy 350, Ford Windsor, Holden 308, Ford 351 Cleveland

STEEL NITRIDE TOP RING & NAPIER SECOND RING

Premium Proline Series piston rings. 

Stainless Steel Nitride Top Ring: Stainless Steel Nitride top rings offer superior wear resistance, corrosion protection, and high-temperature performance compared to standard rings. The nitride coating provides exceptional hardness and low friction, making them ideal for high-performance, marine, and severe-duty applications with extended service life

Napier Ring Design: The Napier 2nd ring features a distinctive stepped or tapered face profile, often with a slight bevel or chamfer on the lower edge. This creates a specific sealing geometry that promotes better oil control while still maintaining compression sealing. The stepped design helps create a wiping action that assists with oil return to the crankcase

Bore (in.):  4.040 in.

Bore (mm): 

Piston and Ring Oversize (in.):   +040" Standard Bore

File Fit:  *Slight File to fit.

Gas Ported:  No

Top Ring Included:   Yes

Top Ring Thickness:  1.5mm

Top Ring Material:  Gas Nitride Steel

Second Ring Thickness:  1.5mm

Second Ring Material:  Cast / Phosphate Coated

Second Ring Face/Style:   NAPIER

Oil Ring Included:  Yes

Oil Ring Thickness:  3.0mm 

Oil Ring Material:   Chrome plated carbon steel

Quantity:  Sold as a set of 8.

Piston Rings made in Japan by NPR