SL2019-682/JAG New recommendation for grinding angle of exhaust valve spindle

The “wide seat” bore-cooled bottom piece design was introduced in response to the steadily raised temperature level of combustion chamber components aiming at energy efficiency and compliance with emission regulations.

The “wide seat” design alone has been in service since 2015 and introduced in the bore-cooled design since 2018.This Service Letter introduces an update of the machining toler-ances on the spindle seat angle.