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Mercury Racing Unveils 860- and 1,750-hp QC4v Engines
Created: Thursday, 16 February 2017 07:15
Written by Matt Trulio
With two new QC4v engines introduced, it's been a big opening morning at the Miami International Boat Show for Mercury Racing.
With this morning’s unveiling of Mercury Racing's new turbocharged 1,750-hp engine and its new naturally aspirated 860-hp engine at the Miami International Boat Show, Mercury Racing has grown its family of quad overhead cam/four-valve (QC4v) engines to seven models including the 1100, 1350, power adjustable 1550/1350 and 1650 offerings.
Designed, developed and manufactured in-house, the naturally aspirated 9.0-liter 860-hp engine features Mercury Racing’s exclusive aluminum four-valve cylinder heads and dual overhead camshaft valve train, according to a press release from the Fond du Lac, Wis., high-performance marine engine and accessories company. These quad cam, four-valve heads are integrated with Mercury Racing’s proprietary V-8 cylinder block packed with the company’s designed and specified hardware, according to the release.
Running on 89-octane fuel, the Mercury Racing 860 engine produces 860 hp at 6,800 rpm. (Operating range is 6,300 to 6,800 rpm.) The 1750 engine produces 1,750 hp at 6,800 rpm on 117 MON race fuel. (Operating range is 6,500 to 6,800 rpm.)
The 860 is Mercury Racing’s first QC4v engine to feature a wet sump oil system. The Mercury Racing-designed oil pan features dedicated baffling and a custom windage tray. That, combined with an engine mounted oil pump, keeps oil away from the crankshaft, "virtually eliminating parasitic power loss." Rigging and installation is also facilitated by not having a remote-mounted oil sump, according to the release. Exclusive to the 860, the engine's new camshafts feature custom lobes for greater valve lift. This design feature, combined with high-velocity cylinder head intake ports, provides maximum air flow to the combustion chamber. New pistons, also designed exclusively for the naturally aspirated engine, respond to the fuel/air charge with an 9.75:1 compression ratio.
On the 1750 engine side, new twin turbochargers—each with a larger compressor wheel—provide greater airflow for enhanced power and torque. The engine also is equipped with a 105-amp charging system, which according to the release “provides an ample supply of power for an array of marine electronics
Both engines come standard with Mercury Digital Throttle and Shift (DTS) technology, which features one-touch Smart Start, automatic throttle synchronization and shadow mode for multiple engine applications. According to the release, Mercury Racing DTS Zero Effort controls “provide an intuitive control experience—precisely signaling driver intent.”
Both powerplants also boast Mercury Racing’s exclusive PCM-based Engine Guardian system, which monitors engine functions to forewarn of possible problems that could lead to engine damage. The system also can help prevent engine-overheating damage by sensing not only engine temperature but also cooling water pressure. By sensing water pressure and temperature, the system provides advanced warning to the PCM, which then reduces engine power before temperature related engine damage takes place.
Closed-cooling systems are integral to both engines. Engine oil and glycol for the closed-cooling system are routed around the engine via a series of tubes. The tubes are encapsulated in a casting filled with seawater, which serves as a coolant. A heat exchanger provides for a higher seawater flow rate for enhanced cooling.
A dry-sump M6 surface-piercing stern drive comes standard on the Mercury Racing 860, which has a two-year factory warranty. A surface-piecing M8 drive is standard for the 1750, which as a “thoroughbred competition engine” is not warrantied. A variety of five- and six-blade Mercury Racing CNC propellers are offered for both engines.
Prices for the 1750 and 860 engines have not been released.