Valve seat ring replacement per piece BMW cylinder head service

Valve seat ring replacement per piece BMW cylinder head service

Replacing a valve seat ring is one of the most demanding tasks in professional cylinder head overhauling. Precise machining, the correct oversize, and expert installation are crucial. In our engine department, we carry out this work in-house using the appropriate machinery and measuring technology.

First, the old valve seat ring is carefully milled out. We then machine the base bore of the cylinder head to the required dimension. For installation, the new seat ring is cooled down to −196 °C using liquid nitrogen, while the cylinder head is heated in a controlled manner. Due to the temperature difference, the seat ring can be inserted with minimal stress and achieves a secure fit in the cylinder head once the temperatures equalize.

This is followed by the precise machining of the valve seat contour on our SERDI 100 contour milling machine. Here, the seat angle and contour are precisely matched to the valve and the intended application. This process is an essential part of a professional cylinder head overhaul, especially for classic BMW 2-valve and BMW boxer engines such as the R65, R80, and R100.

Scope of services per valve seat ring:

• Precise milling of the old valve seat ring
• Re-machining of the base bore
• Controlled heating of the cylinder head in a heating oven
• Cooling of the new seat ring with liquid nitrogen to up to −196 °C
• Expert shrink-fitting of the valve seat ring
• Precise contour machining on the SERDI 100

Note: For multi-cylinder engines and when machining multiple valve seat rings or valve guides simultaneously, the unit price may be reduced. We would be happy to provide you with an individual quote for this.

Valves and valve seat rings are not included in the stated price. The price applies per valve seat ring.