Engine Seal Kit
Cometic C9245-060 S&S Bore Top End Gasket Kit MLS Head Gaskets - 4-1/8 with 060
Cometic C9635-045 EST Top End Gasket Kit Evolution Big Twin .045" Head Gasket
Cometic C9808F Heavy Duty Top End Gasket Kit for 1999-2006 Harley-Davidson Big Twin
Cometic C9763-065 EST Top End Gasket Kit Harley Sportster 1200 .065" Head Gasket
Cometic C9780-NHG Twin Cam Top End Gasket Kit Without Head Gaskets 3.875" Bore
Cometic C9780-036 EST 1550 Big Bore Twin Cam Top End Gasket Kit .036" Thickness
Cometic C9780-032C EST Top End Gasket Kit for Harley Twin Cam 1550 Big Bore .032" Copper
Cometic C9780-027 EST Top End Gasket Kit 1550 Big Bore Twin Cam 3.875" Bore .027" Head Gasket
Cometic C9767-060 Big Bore Top End Gasket Kit for Harley-Davidson 84-91 Big Twin .060" Bore
Cometic C9854F-1250 EST Top End Rebuild Kit for Harley Sportster 1200 .030" MLS Head Gasket
Cometic C9851-32C Top End Gasket Kit for Harley-Davidson EVO Big Twin .032" Copper Head Gasket
Cometic C9845-NH Twin Cam 88 Top End Rebuild Kit without Head Gasket 1999-2002
Cometic C9951-054 EST Top End Gasket Kit 3.875" Bore .054" Head Gasket Twin Cam
Cometic C9951-040 HD Big Bore Top End Gasket Kit MLS Head Gasket - 1550cc 040
Cometic C9949-040-WB HD 110 CI Top End Gasket Kit 4.000" Bore .040" MLS Head Gasket
Cometic C9949-040-020 HD Top End Gasket Kit Bore Head Gasket - 110ci 4 040
Cometic C9976-T124-036 Top End Gasket Kit Twin Cam 4-1/8" Bore .036" Head Gasket
Cometic C9976-T124-030 EST Top End Gasket Kit 4-1/8" Bore .030" Head Gasket Twin Cam
Cometic C9970-030 EST Top End Gasket Kit .030" Head Gaskets Harley Sportster 1200
Cometic C9967-CUST Heavy Duty Top End Gasket Kit for 1966-84 Shovelhead .040" MLS Head Gasket
Cometic C9949-040-010 HD Top End Gasket Kit Bore Head Gasket - 110ci 4 040
Cometic C9949-027 Top End Gasket Kit Twin Cam Bore MLS Head Gasket - 110ci 4.0 027
Cometic C9926-066 Milwaukee Eight Twin Cam Top End Gasket Kit 4.250" Bore .066" Head Gasket
Cometic C10123-030 Top End Gasket Kit for Harley-Davidson Dyna 3.937" Bore .030" Head Gasket
Cometic C10095-3625 HD Sportster Top End Gasket Kit .030" 3.625" Bore 2004-2006
Cometic C10225-030 Milwaukee-Eight Top End Gasket Kit 4.500" Bore .030" MLS Head Gasket
An engine seal kit bundles the gaskets, O-rings, and oil seals needed to close up an engine after service, so oil, coolant, and combustion pressure stay where they belong. Instead of hunting down individual pieces, a kit gives you a matched set designed for a specific engine, which makes rebuilds, top-end refreshes, and leak repairs faster and more reliable.
Why Engine Seal Kits Matter
Every engine relies on dozens of sealing surfaces: cylinder heads, valve covers, crankcase halves, clutch and primary covers, and rotating shafts. Rubber and composite seals harden, shrink, and crack over time through heat cycles and exposure to oil. Once they fail, the result can be anything from a slow weep to a serious loss of oil or compression. Replacing the seals whenever you open an engine is one of the most cost-effective ways to protect a rebuild.
Types of Kits
- Top-end kits cover the head, base, and upper-engine gaskets, and are typically used during piston and cylinder work.
- Complete engine kits add the lower-end gaskets, O-rings, and often transmission and valve seals for a full teardown.
- Oil seal kits focus on the rotating-shaft and crankcase seals that commonly leak with age.
- Cover and component kits, such as primary cover or rocker cover sets, address a single area of the engine.
What to Consider When Shopping
Fitment is the first priority. Seal kits are engine-specific, so match the kit to your exact model, displacement, and year. Next, check what is included: some kits omit oil seals or valve stem seals, which you may need to buy separately. Finally, consider material and construction, such as beaded silicone primary gaskets, multi-layer metal head gaskets, or fluoroelastomer seals for heat and oil resistance.
Top Brands in Engine Seal Kits
James Gasket is a U.S. specialist known for sealing solutions for Harley-Davidson engines, offering primary, cam, rocker, and transmission kits that cover everything from vintage Flathead and Panhead models to modern Twin Cam engines.
Athena is an Italian manufacturer with decades of experience supplying gaskets to motorcycle makers, and its top-end and complete kits include gaskets, rubber parts, and valve stem seals for a full rebuild.
Elring is a long-established German sealing specialist whose engine gaskets and seals are widely used in European automotive applications, making it a go-to for precise OE-style fitment.
Vertex offers a broad range of top-end, complete, and oil seal kits, built to match the company's piston and engine rebuild components, especially for off-road and powersports engines.
Rebuild Tips
Clean all mating surfaces thoroughly, replace old seals rather than reusing them, and follow the factory torque sequence for covers and heads. A quality kit combined with careful assembly is the best insurance against leaks after a rebuild.