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Cylinder Head Restoration

Pre-70 BMW Heads

Materials

  • Guides: Custom machined Ampco 45. Valve guide ID and OD diameters are concentric with .0005" (.013mm) TIR. Shown below are custom R69/R69S and R50/R60 valve guides.

  • Valve seats: Hi-Chrome SAE10b/5 globular perlite and tempered martensite with a uniform dispersion of chromium carbides.

  • German sourced valves, springs, collars and retainers. Alternative German or Swiss high quality replacement parts are used when applicable.

Process

  • Heads are inspected, disassembled, hot tank cleaned and again inspected.

  • The heads are media blasted.

  • All critical dimensions and components are again inspected.

  • Valves are ground (as required) on a Kwik-Way valve grinder which has a spindle chuck TIR at .0005" (.013mm) or less.

  • Valve bores (ID & OD) are machined using a precision Sunnen honing machine and tooling.

  • Seats features (both OD and valve interface angles) are processed with all carbide tooling as applicable ona Rottler SG7 machine

  • Heads are processed in a commercial ultrasonic cleaner and assembled

Post-70 BMW Heads

Materials

  • German sourced standard, first and second overize guides.

  • Valve seats: Hi-Chrome SAE10b/5 globular perlite and tempered martensite with a uniform dispersion of chromium carbides.

  • Factory BMW valves, springs, collars and retainers. Alternative German or Swiss high quality replacement parts are used when applicable.

Process

  • Heads are inspected, disassembled, hot tank cleaned and again inspected.

  • The heads are media blasted.

  • All critical dimensions and components are again inspected.

  • Valves are ground (as required) on a Kwik-Way valve grinder which has a spindle chuck TIR at .0005" (.013mm) or less.

  • Valve bores (ID & OD) are machined using a precision Sunnen honing machine and tooling.

  • Seats features (both OD and valve interface angles) are processed with all carbide tooling as applicable on a Rottler SG7 machine.

  • ​Heads are processed in a commercial ultrasonic cleaner and assembled

s_guides.JPG
5060_guides.JPG

Equipment List

  • Rottler SG7 Seat & Guide Machine

  • Sunnen MBB-1660-D Honing Machine

  • Kwik-Way CV1397 Valve Grinder

  • Rockwell 21-100 Milling Machines

  • South Bend 9" Model A Custom Built Lathe

  • Miller Mig and Tig Welders for fin and thread repair

  • Metrology Equipment: Sunnen, Starrett, Mahr, Mitutoyo, and others.

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