Upgraded B58 Cam Cap Bolts
The OE B58 Fasteners are TTY (Torque to Yield), this method is cheap to produce in large quantity using mediocre material standards. This method of fastening allows each fastener to reach its maximum theoretical elongation to provide maximum clamping force given that material property and strength.
The major problem with this method is that the fasteners are not reusable. The second problem is that under scrutiny of clamp load 2 fasteners side by side are not applying the same appropriate force within reason. If we cannot rely on even distribution of load, we cannot rely on these fasteners and its showing in the failures we are seeing. The third problem is the availability of replacements, this means a lot of these fasteners are not being replaced during engine rebuilds.
The OE Cam Cap Bolts have been a problem BMW has been aware of for some time now. The hardware has been revised and certain models have open TSBs. Although the the improvements from BMW is a step in the right direction we feel this latest update isn't a fix. Our upgraded hardware kit will prevent the cam caps from becoming loose and causing damage to the cylinder heads casting.
- Specifically designed to support the load and tensile requirements of increased output.
- Required to reach ASTM conformance certification. All Material must conform to AMS batch raw materials.
- Thread engagement and shank is optimized for each given bolt in its specific location.
- Meet or exceed a minimum allowable tensile strength of 190kpsi.
- Custom age hardened
- Corrosion resistant, there is no coating or plate film to wear or degrade.
- Reusable indefinitely unless over yielded past acceptable elongation.
6 port kits contain 13 long and 22 short bolts, use a dab of engine oil and toque to 13ft/lb