air flow
 

hello
I'm currently rebuilding my 2.7RS engine, and notice there's surely something to do around intake valve guide to help air flow...
the shape should be slightly modified according to aerodynamics theory.. did you try something there
It's maybe a secret, :D you may answer "yes" or "no"
if not, i continue polishing, maybe it's not a good idea....
regards
Philippe

Be carefull, the metal gets thin. You can do more harm than good if you don't know what you are doing. Polish the exhaust ports, not the intake; also polish the chamber.

There is a saying "to flow is to know". Meaning is that you must have a flow bench to know what you are doing.

I can offer a suggestion that always works in all engines on the intake. Its usually the most significant improvment possible. It is to smooth out the short side radius (if there is one) on the intake port. There is usually some flashing or a small bump on this side and removing it will usually improve the flow from 5 to over 50 percent, depending on the engine and the ammount of junk on the radius.