The valve train is supported by hydraulic lifters, and does not require an adjustment. If you have ticking, you could have a lifter that is not working as it should. Take a look at the grade of oil you are using and how recently it has been changed. Make sure you have a good filter as well. Sometimes just a simple oil and filter change can quiet down noisy lifters (if this is the noise you are indeed hearing). Other than that, some diagnosis should be performed to see what is happening.