Precision Racing Oversize Head Stud Washers
When fitting aftermarket head studs to your engine they are often supplied with inadequate washers, these washers have a smaller external diameter (22mm) then the factory washers (27mm) which does not cover the whole surface area of the aluminium head stud boss, so when cylinder pressures are increased with more power or detonation, the aluminium can mushroom over the washer which reduces the fasteners preload and there for its clamping capacity.
This is generally overlooked, and un-known to many that sell cheaper stud and washer kits, however it can be the root cause of cylinder head gasket sealing issues and/or catastrophic engine failure if not addressed.
Our solution is our custom made washers which cover the whole aluminium head bolt boss, this almost doubles the surface area covered by the washer, giving the stud a larger more even load area so that you can be confident when pushing your Barra!!