Exhaust Manifold Gasket – Fits MerCruiser, OMC, Volvo Penta V8 454-540 CID (Replaces 27-46820)
Exhaust Manifold Gasket – Fits MerCruiser, OMC, Volvo Penta V8 454-540 CID (Replaces 27-46820) is backordered and will ship as soon as it is back in stock.
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Exhaust Manifold Gasket – Fits MerCruiser, OMC, Volvo Penta V8 454-...
Product Details
This high-quality Exhaust Manifold Gasket – Fits MerCruiser, OMC, Volvo Penta V8 454-540 CID (Replaces 27-46820) provides a crucial seal between the cylinder head and the exhaust manifold, preventing exhaust gas leaks. It is engineered for a wide range of V8 big block GM engines, including MerCruiser 454, 482, 496, 502, and 540 CID models (1978–2001), Volvo Penta V8 454/502 CID engines (1992+), and various OMC and Crusader V8 power plants.
This gasket serves as a direct replacement for numerous OEM and aftermarket part numbers, including Mercury 27-46820, Volvo Penta 3852472, OMC 3852472, Crusader 96653, and Sierra 18-0418, ensuring broad compatibility.
- Installs directly between the cylinder head and the exhaust manifold.
- Made from a durable composite and metal material blend to withstand high temperatures and the harsh marine environment.
- Guaranteed to meet or exceed original equipment specifications for fit, form, and function.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 27-46820 |
| Mercury | 27-46820A1 |
| Volvo Penta | 3852472 |
| OMC | 0508878 |
| OMC | 0778127 |
| OMC | 0909613 |
| OMC | 3852472 |
| Crusader | 96653 |
| Sierra | 18-0418 |
| GLM | 33760 |
| OSCO | CW-GH |
| Barr | CHVA470000 |
| Barr | MC47-27-46820 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Fits a comprehensive range of Mercury / MerCruiser V8 big block models from 1978 to 2001. Please verify your engine's serial number falls within the specified ranges for an exact match.
Compatible with Volvo Penta 7.4L (454) and 8.2L (502) GM-based engines manufactured from 1992 onward.
Suitable for specific OMC and Crusader V8 engines utilizing GM 454 and 502 CID blocks in sterndrive and inboard configurations.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| MerCruiser | 370 TRS GM 454 V-8 | 330 | 4-Stroke | 1978–1985 | 27-46820 | Serial #4179554-6721527 |
| MerCruiser | 370 TRS GM 454 V-8 | 330 | 4-Stroke | 1985–1987 | 27-46820 | Serial #6721528-0B714586 |
| MerCruiser | 400 TRS GM 454 V-8 | 340 | 4-Stroke | 1980–1986 | 27-46820 | Serial #4179554-0B457644 |
| MerCruiser | 420 GM 454 V-8 | 420 | 4-Stroke | 1987–1989 | 27-46820 | Serial #0A398941-0B622418 |
| MerCruiser | 425 GM 454 V-8 | 425 | 4-Stroke | 1990–1992 | 27-46820 | Serial #0A398941-0D937011 |
| MerCruiser | 425 (GEN. V) GM 454 V-8 | 425 | 4-Stroke | 1992–1993 | 27-46820 | Serial #0A398941-0D937011 |
| MerCruiser | 440 TRS GM 454 V-8 | 440 | 4-Stroke | 1983–1986 | 27-46820 | Serial #4179554-0B485220 |
| MerCruiser | 450 (GEN. V) GM 454 V-8 | 450 | 4-Stroke | 1995–1996 | 27-46820 | Serial #0F347100-0F347277 |
| MerCruiser | 460 TRS GM 482 V-8 | 460 | 4-Stroke | 1983–1986 | 27-46820 | Serial #4179554-6181046 |
| MerCruiser | 465 GM 502 V-8 | 465 | 4-Stroke | 1990–1992 | 27-46820 | Serial #0C849992-0F213244 |
| MerCruiser | 465 (GEN. V) GM 502 V-8 | 465 | 4-Stroke | 1992–1994 | 27-46820 | Serial #0C849992-0F213244 |
| MerCruiser | 500 (GEN. V) GM 502 V-8 | 500 | 4-Stroke | 1994–1995 | 27-46820 | Serial #0F213293-0F615766 |
| MerCruiser | 500 (GEN. V) GM 502 V-8 | 500 | 4-Stroke | 1996 | 27-46820 | Serial #0F615767-0F745159 |
| MerCruiser | 500 (GEN. VI) GM 502 V-8 | 500 | 4-Stroke | 1997–1998 | 27-46820 | Serial #0F745195-0F877722 |
| MerCruiser | 500 (GEN. VI) GM 502 V-8 | 500 | 4-Stroke | 1997–1998 | 27-46820 | Serial #0K000001-0L000737 |
| MerCruiser | 500 (GEN. VI) GM 502 V-8 | 500 | 4-Stroke | 1997–1998 | 27-46820 | Serial #0L000768-0L001772 |
| MerCruiser | 500 (GEN. +) GM 502 V-8 | 500 | 4-Stroke | 1999 | 27-46820 | Serial #0L414639-0L601036 |
| MerCruiser | 500 Bulldog GM 540 V-8 | 500 | 4-Stroke | 1990–1996 | 27-46820 | Serial #0C577254-0F745405 |
| MerCruiser | 500 Bulldog | 500 | 4-Stroke | 1999–2001 | 27-46820 | Serial #0L414620-0M050281 |
| MerCruiser | 525 SC GM 454 V-8 | 525 | 4-Stroke | 1991–1992 | 27-46820 | Serial #0D456000-0F348963 |
| MerCruiser | 525 SC (GEN. V) GM 454 V-8 | 525 | 4-Stroke | 1992–1995 | 27-46820 | Serial #0D456000-0F348963 |
| MerCruiser | 525 SC (GEN. V) GM 454 V-8 | 525 | 4-Stroke | 1996 | 27-46820 | Serial #0F615814-0F745215 |
| MerCruiser | 600 SC GEN IV & V GM 502 V-8 | 600 | 4-Stroke | 1991–1996 | 27-46820 | Serial #0D456489-0F877642 |
| MerCruiser | 454 MAG. BRAVO (GEN. V) GM 454 V-8 | 385 | 4-Stroke | 1992–1994 | 27-46820 | Serial #0D805069-0F304999 |
| MerCruiser | 454 MAG. BRAVO (GEN. V) GM 454 V-8 | 385 | 4-Stroke | 1995–1996 | 27-46820 | Serial #0F305000-0F801699 |
| MerCruiser | 454 MAG. BRAVO (GEN. V) GM 454 V-8 | 385 | 4-Stroke | 1996–1997 | 27-46820 | Serial #0F801700-0K999999 |
| MerCruiser | 454 MAG. BRAVO GM 454 V-8 | 330 | 4-Stroke | 1988–1992 | 27-46820 | Serial #0B721206-0D805068 |
| MerCruiser | 7.4L BRAVO (GEN. V) GM 454 V-8 | 310 | 4-Stroke | 1992–1996 | 27-46820 | Serial #0D603118-0F800699 |
| MerCruiser | 7.4L BRAVO (GEN. VI) GM 454 V-8 | 310 | 4-Stroke | 1996–1997 | 27-46820 | Serial #0F800700-0K999999 |
| MerCruiser | 7.4L MIE (LH) GEN. V GM 454 V-8 | 310 | 4-Stroke | 1992–1996 | 27-46820 | Serial #0D715494-0F820141 |
| MerCruiser | 7.4L MIE (LH) GEN. VI GM 454 V-8 | 310 | 4-Stroke | 1996–1997 | 27-46820 | Serial #0F820142-0K999999 |
| MerCruiser | 7.4l MIE W/B/W GM 454 V-8 | 310 | 4-Stroke | 1988–1992 | 27-46820 | Serial #0B788366-0D715493 |
| MerCruiser | 7.4L MIE W/HURTH GM 454 V-8 | 310 | 4-Stroke | 1989–1992 | 27-46820 | Serial #0C391564-0D715493 |
| MerCruiser | 8.2L MIE GEN. V GM 502 V-8 | 405 | 4-Stroke | 1993–1996 | 27-46820 | Serial #0D857200-0F819619 |
| MerCruiser | 8.2L MIE W/HURTH GM 502 V-8 | 405 | 4-Stroke | 1990–1992 | 27-46820 | Serial #0C878221-0D857199 |
| MerCruiser | 496 MAG (Base Model) | 375 | 4-Stroke | 2000–2001 | 27-46820 | Serial #0M025000-0M687082 |
| MerCruiser | 496 MAG (H.O. Model) | 425 | 4-Stroke | 2000–2001 | 27-46820 | Serial #0M025000-0M687143 |
| MerCruiser | 8.1L INBOARD (Base) | 375 | 4-Stroke | 2000–2001 | 27-46820 | Serial #0M026000-0M319124 |
| MerCruiser | 8.1L INBOARD (H.O.) | 420 | 4-Stroke | 2000–2001 | 27-46820 | Serial #0M026000-0M319190 |
| Volvo Penta | V8 7.4/454 | 310+ | 4-Stroke | 1992+ | 3852472 | GM-based engines |
| Volvo Penta | V8 8.2/502 | 385+ | 4-Stroke | 1992+ | 3852472 | GM-based engines |
| OMC | 7.4L GM 454 CID V8 | 300+ | 4-Stroke | 1991+ | 0909613/3852472 | Sterndrive and inboard |
| OMC | 8.2L GM 502 CID V8 | 375+ | 4-Stroke | 1991+ | 0909613/3852472 | Sterndrive and inboard |
| Crusader | 454 CID V8 | 300+ | 4-Stroke | 1990+ | 96653 | Inboard applications |
| Crusader | 502 CID V8 | 375+ | 4-Stroke | 1990+ | 96653 | Inboard applications |
Technical Specs
- Product Type
- Exhaust Manifold Gasket
- Installation
- Between cylinder head and exhaust manifold
- Material
- Composite / Metal
- Application
- V8 Big Block GM engines
- Engine Displacement
- 454-540 CID (7.4-8.8L)
- Engine Types
- Stern drives and inboards
- Dimensions
- 53.0 x 10.5 x 0.2 inches (1346.2 x 266.7 x 5.08 mm)
- Weight
- 0.06 lbs (0.027 kg)
- Quantity per Package
- 1
- Warranty
- 1 year manufacturer warranty
- OEM Reference
- Mercury-Mercruiser 27-46820
What’s in the Box
- 1 x Exhaust Manifold Gasket (27-46820)
Installation Notes
- Ensure the engine is completely cool before beginning work.
- Disconnect the battery and relieve any pressure from the cooling system.
- Carefully remove the exhaust manifold, taking note of all connections.
- Thoroughly clean both the cylinder head and manifold mating surfaces. Remove all traces of old gasket material and carbon buildup.
- Position the new gasket over the exhaust ports, ensuring correct alignment.
- Reinstall the exhaust manifold, and tighten the bolts in the sequence and to the torque specifications recommended by the manufacturer.
- Reconnect all hoses, sensors, and the battery.
- Start the engine and carefully check for any exhaust or coolant leaks around the manifold.
Troubleshooting & FAQ
How do I confirm this gasket fits my specific engine?
The best way to ensure compatibility is to match your existing part number to one listed in our Part Number Matrix. Additionally, check your engine model and serial number against our detailed compatibility tables. If you're still unsure, please contact us with your engine details before purchasing.
What are the signs of a failing exhaust manifold gasket?
Common symptoms include a loud ticking or tapping noise from the engine bay (especially when cold), visible soot or black streaks around the manifold-head connection, a decrease in engine performance or fuel efficiency, and the smell of exhaust fumes inside the boat.
How often should this gasket be replaced?
Exhaust manifold gaskets do not have a fixed replacement interval. They should be replaced whenever the exhaust manifold is removed for service or if any signs of a leak are detected. It is good practice to replace them when installing a new manifold.
Can I reuse my old gasket?
No. We strongly advise against reusing old exhaust gaskets. They are designed for one-time use and crush to create a seal. Reusing an old gasket will almost certainly result in an improper seal and exhaust leaks.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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