Anchor Atlantic Enterprises LLC

Porsche 911 cylinder heads before reconditioning

Heads are disassembled and inspected. All components are numbered and checked for cracks and wear.
Valve stems often exhibit excessive wear, in cars with high mileage and early style valve seals.

Porsche 911 cylinder heads before reconditioning

All parts are cleaned ultrasonically in a 3523 Classic machine.

3523 Classic Ultrasonic machine

Heads after cleaning and before valve guide replacement and machine work.
Notice how worn the factory phosphorus bronze 9 mm guides are. This is typical of 911 / 930 heads with high mileage. In this situation, the valves can not properly seat and seal effectively.
Improper installation techniques can destroy the cylinder heads.
We are very experienced in proper valve guide removal and installation.

Heads after cleaning and before valve guide replacement and machine work.

Cylinder Surface Machining
911 / 930 heads distort and erode at the cylinder mating surface.
Machining this surface on all six heads, to the same dimension, is critical.
Unfortunately, most shops overlook this process.
Some heads require as little as .001" to .002" of material removed. We cut every cylinder head we rebuild.
Our method of refinishing assures a flat and parallel surface for a sure seal between the head and cylinder.

911 Heads after valve guides and machine work completed.
Proper valve to guide clearance is important for heat dissipation and long life of the valve seat.
Each valve is fitted to its guide and numbered.
Valves and valve seats are machined with multiple angles (competition valve job).
Special attention is given to the seating location on the valve face and width of the seat.

911 Heads after valve guides and machine work completed.

Close-up of machined cylinder head before assembly.
All studs and spark plug threads are checked and repaired when necessary.
Final wash before assembly is performed.
Spring tension is tested and springs are replaced when necessary.
Valve length and spring installed height are checked and machined to specifications.
Guides and stems are lubricated and installed with Viton seals.
We have found excessive stem wear in the seal area with other popular "white" seals.

Close-up of machined cylinder head before assembly

Cylinder Heads after assembly to factory specifications.
At this point, the heads are ready for shrink wrap and packaging. Each head is boxed separately and grouped together in one heavy duty carton ready for shipping.

Cylinder Heads after assembly to factory specifications.