8.1L MPI Horizon Inboard (V-Drive) NEW Engine ONLY Plus-Series (NLA)

8.1L MPI HORIZON INBOARD MIE- (V-Drive) ENGINE ONLY 2023-PY. Quicksilver PLUS-SERIES Engine PT# No Longer Available (NEW) with 3-Year Mercury Marine Warranty.

370 HP @ 4600 RPM. 8.1L Fully Dressed Marine Engine.

FEATURES: 100% NEW Quicksilver: Heavy Duty Iron Block with Splayed 4-Bolt Main Bearing Caps, Priority Main Oiling System, 8.6:1 Hypereutectic Pistons, Roller Camshaft, 1.7:1 Rocker Arms, Forged Steel Steel Camshaft, 1.7:1 Rocker Arms, Forged Steel Crankshaft, Quicksilver Iron Cylinder Heads featuring Black-X Valve Tech. Multi-Port Fuel injection using Cool Fuel-3, Closed Cooling, Dry Joint Exhaust, 316 Stainless Steel Exhaust Elbows, +2″ Risers Standard, PCM 555, Engine Guardian System, SmartCraft Ready, Mechanical Throttle & Shift, Serpentine Accessory Drive, Oil Cooler, Inboard High Mount Starter, 14-pin Harness. Runs on 87-Octane Fuel.

SPECIFICATIONS: HP / kW @ flywheel: 375 / 272 Maximum RPM (WOT): 4200 – 4600 Engine type: 8.1L Mercury V-8 iron block and heads. Displacement (CID/L): 496 / 8.1 Bore and stroke: 4.25 x 4.38″ / 108 x 111 mm. Compression ratio: 8.6:1   Fuel requirement: 87 octane (R+M)/2. Engine control system: PCM 555. Fuel delivery system: GEN III cool fuel. Fuel injection system: Sequential multi-point electronic fuel injection (MPI). Air induction: Two-piece long runner intake with 75 mm throttle body. Ignition: Distributorless ignition with knock control. Alternator amps: 65 amp. Water drain system: Single point air actuated. Exhaust system: Iron manifolds with 4″ / 102 mm diameter 316 stainless steel dry joint exhaust elbows, +2″Risers Standard. Cooling system: Brass sea water pump Closed cooling. Long life 5-year antifreeze. Accessory drive system: Serpentine belt. Lubrication system: High flow oil pump and copper engine oil cooler. Recommended oil: SAE 25W-40 NMMA Certified FC-W Synthetic Blend. Engine guardian system: Exhaust manifold temperature High coolant temperature Knock control Low oil pressure Low voltage Low water pressure Over-rev Transmission temperature.

Transmission coupler: Dual-stage coupler – MUST BE CHANGED FOR 72C TRANSMISSIONS


Condition New
Manufacturer Quicksilver Products / Mercury Marine
Model Year 2023-PY
Model 8.1L MPI Horizon Inboard- Down Angle Plus-Series Engine Only
Retail Price WAS $35,556.25
Price: No Longer Available
Color Black
Stock Number
Additional Pricing Information 3-YEAR MERCURY MARINE FACTORY WARRANTY.

1) Engine is not equipped with a decorative plastic engine cover An old cover can be transferred from an older engine or simply left off.
2) Because this is a completely new engine and not a major repower assembly, the old engine being replaced is to be returned per EPA, 1068.240.

3)  Payment is by Wire Transfer, Cash, PayPal or Credit Card.
4)  Add 4% to total price if paid by PayPal. Add 5% to total price if paid by Credit Card in-Store Only.
5)  Can Ship to Marine Service Center in Continental United States ONLY.
6) Shipping is at additional charge. Call for shipping quote.  F.O.B. San Dimas, CA.

Weight: 999 lbs

REPLACES: All makes of big block & LS inboard engines: 6.0L, 7.4L, 454, 8.1L & 502.

*Price, if shown, does not include government fees, taxes, additional equipment, installation or any finance charges (if applicable). Final actual sales price will vary depending on options or accessories selected.
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