im in the process of porting and poishing my b16 pr-3 head and was wondering how far to go with the polishing? i have consentrated on one combustion chamber and have got it to a highly polished/mirror finish, going by pics on sites like endyn it would seem i have taken it too far as theirs are rougher than mine. i was just wondering what the best finish is to have and why?

any help much appreciated, thanks

 

Think about what needs to happen to the air/fuel, it needs to tumble and mix as it fills the chamber. A mirror finish won't do that. Add some roughness to the finish.

 

Many porters finish with 80 grit and maybe a medium cross buff pad.