This custom Mercury V6 powerhead stud kit is engineered for use with 12-inch studs-down Mercury Racing mid-sections, found on competition platforms like the SST-120, S3000, F1 V6, and various 2.5-liter drag race outboards. Designed to handle high-RPM stress, heat cycling, and structural load, this kit offers race-grade reliability in demanding conditions.
Each stud is machined from 190,000 psi tensile strength chromoly steel, finished with a protective black oxide coating. The studs are designed for downward installation from the powerhead into the block through the upper flange of the mid-section.
Design Features and Kit Configuration
The studs are broached with an internal Allen drive, simplifying removal and torque application in tight marine engine bays. Length and thread pitch are matched to Mercury’s racing mid-section geometry for consistent preload and secure engine mounting.
The complete kit includes eight high-strength chromoly studs, eight case-hardened washers designed to seat precisely in the mid-section’s recessed castings, and eight stainless steel nylock nuts for vibration-resistant retention. This configuration is engineered to maintain sealing and alignment under dynamic engine loads and thermal expansion.
OEM Compatibility and Application
This kit replaces Mercury OEM stud part numbers 822182 and 8221821, used in assemblies like Driveshaft Housing 821986A5. The thick washers correspond to Mercury parts 12-856774 and 8M0214963, ensuring accurate fit and load distribution.
It is fully compatible with 2.4L and 2.5L Mercury Racing V6 engines configured with 12-inch offshore mid-sections in F1, tunnel hull, drag, and SST racing classes, where powerhead retention is critical under prolonged high-speed operation.
What's Included?
Includes eight (8) Mercury Powerhead Studs sized for the 12" studs-down Mid Section, eight (8) case-hardened thick-washers to fit the nut seats cast in the mid, eight (8) stainless steel nylock nuts, and one (1) Allen Key Wrench.
Corrosion Prevention for ARP Chromoly Studs
To prevent corrosion on ARP-grade chromoly studs, clean them thoroughly before use and apply a light coat of high-quality motor oil or a corrosion-inhibiting lubricant such as WD-40. This protects threads during installation and resists moisture intrusion.
Reapply lubricant periodically, especially in saltwater or humid environments. When not in use, store studs in a clean, dry place to preserve surface integrity and prevent oxidation of the black oxide finish.
Contact Mike at 714-697-1716 or mike@buckshotracing77.com for technical support