The 73-piece Buckshot Racing #77 Titanium (Ti-6Al-4V) Cylinder Head Stud Kit is precision-engineered for Mercury 2.0L, 2.4L, and 2.5L 2-stroke V6 outboards, built to handle the demands of outboard drag racing, tunnel boat racing, offshore racing, and circle boat racing.
Made from aerospace-grade materials with rolled threads, this kit delivers exceptional weight savings, strength, and corrosion resistance, setting a new industry high bar standard for high-performance marine engines.
Ti-6Al-4V titanium (atomic number 22), widely used in aerospace and Formula 1 racing, is the core material of this stud kit. It is 45% lighter than stainless steel and 55% lighter than alloy steel, significantly reducing engine weight.
The Ti-6Al-4V is 30% stronger than stainless steel, offering superior resistance to deformation and stress under high-performance conditions. This can only aid combustion efficiency, acceleration, and top speed, essential in competitive racing.
Our broached US SAE 5/32-Inch Hex Key Head design of these studs allows easy installation and removal using a standard USA 5/32-Inch Allen Wrench, simplifying powerhead rebuilds and reducing setup time during engine maintenance. Combined with this kit provides unmatched durability.
Our Rainbow PVD (Physical Vapor Deposition) coating provides and impressive 2000-3000 HV hardness, up to 10x harder than electroplated finishes, while its ultra-thin layer (0.5-5 microns) provides 30-50% greater corrosion resistance, 30-70% less wear, and performance stability in temperatures up to 500°C (932°F). The low friction coefficient (as low as 0.1) ensures precise torque application without thread damage.
The 12-point Titanium Ti-6Al-4V "speed" nuts are lightweight and durable, offering 45% weight savings over stainless steel nuts.
Their precise 12-point design evenly distributes torque, reduces the risk of rounding, and maintains fastener integrity during high-stress operation.
Install with a standard 1/2-inch drive 12-point SAE socket, which also allows for more wrench clearanece comapred with a stock 9/16-inch head.
Completing the kit are grade-8, case-hardened, extra-thick washers provide superior load distribution and prevent damage to aluminum heads, while the yellow zinc finish adds corrosion protection.
This 73-piece Head Stud Kit includes:
24 Titanium Mercury Cylinder Head Studs with rolled threads
24 Titanium 12-point 1/2 Drive Nuts
24 Grade-8 Extra-thick Case Harden Washers
1 Ball-End Hex Key Allen Wrench (for each install!)
Introductory Race Net Pricing is $295 a kit!
It is compatible with all 1976-2005 gasketed and O-ring cylinder blocks manufactured by Mercury Mariner, Mercury Hi-Performance, Mercury Racing, and Mariner.
The kit replaces OEM part numbers 10-98534, 12-25909, 8M0125882, 849677, 878217, 10-878217 and more oem part numbers created over the years.
The kits fit a wide range of Mercury outboard engines, including 135 HP, 150 HP, 150 Pro Max, XR2, XR4, XR6, 175 HP, 175 EFI, SST-120, SST-140, 200 HP, XRi, 200 Pro Max, 225 Pro Max, 220 HP Laser, 240 HP Bridgeport, Mod VP, 245 Carb, 260 ROS, as well as SportJet 2.5-liter jet boat motors.
Proper Installation is Important
Start by thoroughly cleaning the block's threaded holes to remove debris and ensure you have good threads in the block.
Thread each stud into the block using the broached 5/32-Inch Hex Key with a standard US SAE 5/32-Inch Allen Wrench, tightening them lightly to a torque of 10-12 ft-lbs (13-20 Nm). Avoid overtightening to prevent damage to the block or threads.
Once the studs are installed, install new gaskets and clean cylinder heads. Place the washers over the studs, ensuring they sit flush against the cylinder head surface. Next, hand-thread the 12-point titanium nuts onto the studs and hand tighten them using a 12-point socket.
When securing the cylinder head, use a torque wrench to tighten the nuts to your specified torque values, typically 30-40 ft. lbs. (34-47 Nm). Tighten the nuts in the inside-out crisscross pattern specified by Mercury, gradually increasing torque in increments to ensure even clamping and a proper seal.
After the initial heat cycle(s), recheck the torque on all fasteners to verify proper alignment and secure installation.
Contact Mike Hill at +1-714-697-1716 or email mike@buckshotracing77.com to learn more or place an order.o
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SKU: Ti-6Al-4V-77
$295.00Price
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