I went through all the problems of
oil consumption that oliver is dealing with, with my first 418W and found out during tear down that my rings were not installed properly by the first engine builder that went out of business shortly after completion of my motor. The rings were improperly installed and the ring gap was way too narrow and they would touch after the engine warmed up. This wound up destroying the ring lands causing ring flutter. I had replaced the intake gasket which also was installed by blind monkeys during the first build. Didn't stop the
oil consumption however. After building a new motor by a master engine builder and over 8k miles on it to date, I only burn a quart of
oil every 2-3k miles. I hate to say it but I think a rebuild is in your future.