Mercury – Exhaust Manifold Gasket | Engine Sealing Series | Composite Marine Gasket | 8M0162486

Overview

If you’ve spent years working on MerCruiser engines, there’s a certain comfort in the parts that just fit right. No wrestling, no guessing, no hoping the seal will hold once the engine heats up. A good manifold gasket gives you that sense of reassurance — the kind you feel when the engine fires up and settles into a smooth, confident rumble. That’s exactly what you get with Mercury Marine part 8M0162486. Whether you're freshening up an older sterndrive or doing preventive maintenance before another long season, installing the right gasket brings a quiet peace of mind that only seasoned boaters fully understand.

Key Features

• Designed for GM Marine small-block V8 engines: 305 and 350 (5.0L and 5.7L).
• Built from durable marine-grade composite materials for a tight, long-lasting seal.
• Engineered to withstand high heat and constant expansion cycles.
• Manufactured to exact Mercury Marine OEM tolerances.
• Helps maintain proper exhaust flow and protect engine components from leaks.

Engine & Boat Compatibility

• Fits MerCruiser sterndrive engines based on GM Marine 305 and 350 small-block platforms
• Compatible with 5.0L and 5.7L V8 configurations
• Common on cruisers, bowriders, sport boats, classic runabouts, and older performance sterndrive setups
• Suitable for engines that see heavy loads, long idle periods, or repetitive temperature swings

Performance & Practical Benefits

An exhaust manifold gasket does more than simply sit between two pieces of metal — it keeps the entire system breathing the way it was designed to. When this gasket is installed, you’ll notice the difference in how cleanly the engine runs, especially under acceleration. No ticking noises, no exhaust leaks sneaking into the bilge, no strange heat patterns along the manifold. Just a tight, reliable seal.

The composite construction gives the gasket the resilience it needs to stand up to marine life — constant heat, vibration, moisture, and the natural expansion of metal every time the engine cycles. Instead of drying out or crushing unevenly like lower-quality replacements, this one keeps its shape and continues to seal even after seasons of use.

For anyone who maintains their own boat, this part feels refreshingly straightforward. It lines up cleanly, seats firmly, and torques down without the frustrating “crumble” some cheaper gaskets suffer from. And once the engine warms up for the first time after installation, you’ll hear and feel the difference — a smoother tone, steadier idle, and that sense of security that comes from knowing nothing is leaking where it shouldn’t.

Why Buy OEM

With something as critical as an exhaust gasket, choosing OEM isn’t about brand loyalty — it’s about reliability. Mercury Marine designs these gaskets to match the exact surfaces and tolerances of MerCruiser manifolds and heads. Aftermarket versions often look the same but lack the heat resistance, density, or precision that marine engines demand.

Using an OEM gasket means fewer breakdowns, longer manifold life, and proper sealing from day one. It’s a small investment that protects much bigger components. As any longtime boater will tell you, these are the kinds of parts where cutting corners always costs more later.

FAQ

Q1: Which engines does the 8M0162486 gasket fit?

It fits MerCruiser V8 engines built on GM Marine 305 and 350 blocks (5.0L and 5.7L).

Q2: What sets it apart from aftermarket gaskets?

Its composite design, OEM-level heat resistance, and exact fitment match Mercury’s engineering standards.

Q3: How can I confirm it’s correct for my engine?

Check your engine model and refer to your owner’s or service manual for compatibility with this part number.

Q4: Is it suitable for both saltwater and freshwater boats?

Yes — it’s built to withstand corrosion, heat, and moisture in either environment.

Q5: Is installation straightforward?

For most mechanically inclined boaters, yes. With proper torque procedures, installation is clean and predictable.