Standard type head studs and nuts are mass produced which unfortunately compromises the specification of the end product. Worst affected are the threaded portions which create problems during torque-down; thread deformation, stud distortion and possible stretch, off-square seating of the nut to head and so on.
Exacting design, material, heat treatment and machining specifications stipulated by Mini Spares are all strictly adhered to during production to ensure a truly high standard of finish. This optimises accurate and even torque-down, eliminates stud distortion and minimises thread deformation therefore prolonging usage. The use of special washers greatly improves even clamp-down. The extra thickness helps to avoid thread-bottoming when using heads that have had a lot of material removed from the face to achieve high compression ratios.
The accuracy attained during production means that a far superior clamp-down is achieved so high torque settings are not usually required. However, it is possible to use up to 75lb ft if necessary. Any more than this the stud gains mechanical advantage over the block, ie. the stud will pull the threads out of the block.
Fitting notes:-
- Wash the studs and nuts clean to ensure no swarf or dirt is in the threads
- Fit studs into block dry
- Oil thread slightly before fitting nuts
- Smear oil on base of nuts
- Fit washers with large countersink to head
- Replace nuts after 4 or 5 uses, to retain accurate torque-down.
