Is there any advantage to sanding/smooth & polishing the 6 inlets on the inlet mani?

i have no idea but at least you can say its been done lol

thought they was quite smooth anyways .. but i'm sure could be made better and a little bigger :)

Yes deffo worth it, done this on mine and you can feel the difference.

Didn't want to waste my time if there's no "real" gain to be had

i have no idea but at least you can say its been done lol

 

:lol::lol::lol:

i did this on my mx bike and you defo could feel the difference. its the castings, theyre ugly and cause turbulance, i used a dremal sanded it all smooth, made them a fraction bigger. then i painstakingly polished it with autosol and cleaned with degreaser. glad i did it

its the castings, theyre ugly and (cause turbulance,) But this is want you want, to help the fuel and air mix.

 

Paul

I think the best thing to do is to grind all of the in perfections out, (especially the miss match at the ajoining faces) so as to make the route from A to B as streamlined and contoured as best as possible. It is more about flow than friction,

Also polishing is not a good idea, it propagates wetting of the side walls,

IE The fuel is drawn from the air flow and sticks to the inside surfaces of the manifold and leads to lean running. (especially when cold, hence rich mixture at start up)

As 300 zedx says, you need a degree of turbulence combined with an aerodynamic flow.