Sierra Piston Ring Set 18-3905,.030 Inch Oversize, for Johnson/Evinrude OMC Outboards, Replaces OMC 396504

The Sierra 18-3905 is a.030 inch oversize piston ring set built for rebuilding Johnson and Evinrude OMC outboard powerheads. When a cylinder has been bored.030 inch over standard to true up worn or scored walls, this ring set restores proper compression and oil control so the rebuilt engine seals and runs like new. Each ring is machined to close tolerances for a consistent, even seal against the cylinder wall, helping the powerhead hold compression and resist blow-by after a rebuild.

The 18-3905 set is part of Sierra's Evinrude Outboard OMC Eagle and Sea Drive piston program, and it interchanges with common aftermarket and OEM ring numbers, making it a straightforward replacement when the original OMC rings are no longer available. Every Sierra part is manufactured to meet or exceed the specification of the original equipment it replaces and is backed by Sierra's customer satisfaction warranty.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3905
• Product Type: Piston Ring Set
• Oversize:.030 inch (30 thousandths over standard)
• Finish: Machined
• Product Dimensions: 0.39 x 0.39 x 0.39 inches
• Weight: 0.08 pounds
• UPC: 030999316998
• Application: Johnson and Evinrude OMC outboard engines
• Category: OMC Eagle and Sea Drive series pistons

Fitment

The Sierra 18-3905 piston ring set is designed for use in Johnson and Evinrude outboard applications, specifically OMC Eagle and Sea Drive series powerheads.

Replaces (OEM)

• OMC 396504
• GLM 24300
• Mallory 9-54418
• Mallory 9-54422
• Wiseco 3530KD

Frequently Asked Questions

What engines is the Sierra 18-3905 piston ring set designed for? The Sierra 18-3905 is designed for use in Johnson and Evinrude OMC outboard engines, specifically the OMC Eagle and Sea Drive series powerheads.

What size oversize is the 18-3905 ring set? It is a.030 inch oversize set, meaning it is sized for a cylinder that has been bored 30 thousandths of an inch over standard to clean up a worn or damaged bore.

Does the 18-3905 replace the OMC 396504 piston ring? Yes, the Sierra 18-3905 is a direct interchange for OMC 396504 as well as GLM 24300, Mallory 9-54418 and 9-54422, and Wiseco 3530KD.

Is Sierra 18-3905 a genuine OEM part or an aftermarket replacement? It is a Sierra aftermarket replacement part manufactured to meet or exceed the specification of the original OMC 396504 ring it replaces.

How much does the 18-3905 piston ring set weigh? The Sierra 18-3905 weighs 0.08 pounds.

What finish do the 18-3905 piston rings have? The rings in the 18-3905 set have a machined finish for a precise, consistent seal against the cylinder wall.

When would I need the.030 oversize 18-3905 rings instead of standard-size rings? You need the.030 oversize 18-3905 set after a cylinder has been bored.030 inch over standard during a rebuild, which is typically done to true up a worn or scored bore.

What are the dimensions of the Sierra 18-3905 piston ring package? The Sierra 18-3905 piston ring set has product dimensions of 0.39 x 0.39 x 0.39 inches.

Is the Sierra 18-3905 covered by a warranty? Yes, the 18-3905 is covered under Sierra's customer satisfaction warranty like all Sierra marine parts.

What is the UPC for the Sierra 18-3905 piston ring set? The UPC for the Sierra 18-3905 is 030999316998.