Hey out there...
I have searched but I really cant find the answer to this question. If the B18 series blocks have the same bore what are the differences? Also what are the benefits of a closed or open deck? Thanks

 

from my experience the ls blocks have a different stroke and also do not have a girdle and oil squirters like the gsr and R motors. also piston size is the same between motors but piston compression different. also ls and crv motors have a different bearing as opposed to the vtec motors. the motor are all real close in design but it is the little things that make them different. honda uses open decks for cooling purposes and to keep the motor somewhat light.