Blow-by: Blow-by is said to occur when air-fuel mixture or the burnt gases from the combustion chamber leak past the piston rings to the sump. This occurs due to wear of cylinder bore and/or piston rings or due to excessive piston ring gaps. Related posts: Personnel Management Operative Functions Administrative Role of PM Competency HR Management Role Change Personnel Policies Personnel Procedures Appealed Policies Implied Policies Specific Policies Personnel records Research Pure research Personnel research Attitude or Opinion Survey Turnover Secondary research Applied research Personnel audit Read more articles Previous PostBio-diesel Next PostBoxer engine