Sierra 18-1957-2 Exhaust Manifold
Sierra 18-1957-2 Exhaust Manifold Product Description
Upgrade your marine engine's performance and reliability with the Sierra 18-1957-2 exhaust manifold, a precision-engineered component designed for demanding boating conditions. Crafted by Sierra Engine Parts, this manifold stands out with its factory-applied paint finish that resists corrosion from saltwater exposure, meticulous packaging to ensure damage-free delivery, and rigorous leak testing to guarantee a secure, watertight seal right out of the box. Boaters trust it for seamless integration and long-term durability in harsh marine environments.
Key Features That Set the Sierra 18-1957-2 Apart
- Corrosion-Resistant Coating: The durable paint application shields against the elements, extending the manifold's lifespan even in brackish or saltwater use.
- Leak-Tested Reliability: Each unit undergoes thorough pressure testing to prevent exhaust leaks and water intrusion, a common failure point in older manifolds.
- Precision Fit and Finish: Engineered to match original specifications, ensuring straightforward bolt-on installation without custom modifications.
- Robust Packaging: Protected during shipping to arrive in pristine condition, minimizing downtime for your vessel.
Recognizing When Your Exhaust Manifold Needs Replacement
Exhaust manifolds endure constant heat cycles, water exposure, and vibration, leading to cracks, corrosion, or gasket failures. Watch for these telltale signs:
- Steam or white smoke from the exhaust, indicating internal water leaks.
- Overheating engine temps due to restricted exhaust flow.
- Rust stains or bubbling paint around manifold ports.
- Unusual rattling noises from the exhaust system under load.
- Reduced power or poor acceleration from backpressure buildup.
Addressing these issues promptly with the Sierra 18-1957-2 prevents catastrophic engine damage, like hydrolock, saving you thousands in repairs.
Performance Benefits for Your Boat
Installing this manifold restores optimal exhaust flow, improving engine breathing for better fuel efficiency and throttle response. Its design minimizes backpressure, helping your outboard or inboard run cooler and quieter. In real-world use, boaters report smoother idling and sustained power during long cruises or towing watersports gear. Plus, the leak-proof construction keeps cooling water out of cylinders, protecting pistons and valves from corrosion.
Pro Tips for Installation and Maintenance
While professional installation is recommended, many experienced DIYers handle it with basic tools. Always:
- Drain the cooling system and disconnect the battery for safety.
- Remove the old manifold carefully, inspecting risers and gaskets for wear.
- Clean mating surfaces thoroughly and use high-temp gasket sealant.
- Torque bolts to manufacturer specs in a crisscross pattern.
- Run the engine on a hose test before sea trial to check for leaks.
For longevity, inspect annually for corrosion, especially if trailered in coastal areas. Pair with quality risers and elbows for a complete system refresh.
Why Sierra Engine Parts Deliver Confidence
Sierra's reputation in the marine aftermarket stems from consistent quality control and materials that rival OEM standards. This 18-1957-2 model exemplifies their commitment, offering boaters a cost-effective alternative without sacrificing performance or safety. Whether you're prepping for fishing trips, weekend getaways, or competitive racing, it keeps your engine firing on all cylinders.
Frequently Asked Questions
What makes the Sierra 18-1957-2 exhaust manifold superior to generic replacements?
It features a pre-applied corrosion-resistant paint, individual leak testing, and protective packaging, ensuring reliability from installation through years of use.
How can I tell if my boat's exhaust manifold is failing?
Look for exhaust smoke with steam, engine overheating, corrosion buildup, or rattling sounds, which signal cracks or water intrusion risks.
Is the Sierra 18-1957-2 easy to install on marine engines?
Yes, it's a direct bolt-on fit with precise engineering, though draining fluids and using proper torque specs are key for best results.
Does this manifold help with engine overheating?
Absolutely—its optimized flow design reduces backpressure, allowing efficient cooling and preventing hot spots in V8 marine setups.
How often should I replace my exhaust manifold?
Every 3-5 years in saltwater or high-use scenarios, or sooner if inspections reveal corrosion or leaks.
Can I use this with standard marine risers?
Yes, it pairs seamlessly with compatible Sierra risers and elbows for a full, leak-free exhaust overhaul.
What maintenance keeps the Sierra manifold performing?
Annual visual checks, flushing with fresh water after saltwater runs, and prompt gasket replacements extend its service life significantly.
Save $221 when you buy the Sierra 18-1957-2 Exhaust Manifold for only $262 from NVN Marine! Same day shipping before 3pm.
Sierra 18-1957-2 Exhaust Manifold Technical Specifications
| Type: | |
|---|---|
| Vendor: |
Sierra Engine Parts |
| Weight: |
47.35 lb |
| Replaces: |
Marine Power 0991-100 |
| Application: |
Port & Starboard center rise with gaskets, most Marine Power GM 7.4 L - 8.2L, V8 big blocks & others. |
Sierra 18-1957-2 Exhaust Manifold User Reviews
Sierra 18-1957-2 Exhaust Manifold Shipping & Return
| Shipping Weight: |
47.35 lb |
|---|---|
| Box Sizes: |
6.00 (h) x 7.00 (w) x 19.00 (l) |
| Cubic Feet: |
798.0 |
| Returnable: |
Yes |
For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.



