jaYmo

I'm wondering whether to get the ports on my 5k cylinder head polished or not. I've been searching the net for info regarding this and a good piece I found (on WIKIPEDIA) was this: The reason that polished ports are not advantageous from a flow standpoint is that at the interface between the metal wall and the air, the air speed is ZERO. This is due to the wetting action of the air and indeed all fluids. The first layer of molecules adheres to the wall and does not move significantly. The rest of the flow field must shear past which develops a velocity profile (or gradient) across the duct. In order for surface roughness to impact flow appreciably, the high spots must be high enough to protrude into the faster moving air toward the center. Only a VERY rough surface does this. My question is, does anyone know if factory-standard, K-series cylinder head ports fall into the VERY rough surface catergory? (Enough so to justify polishing the ports.) Thanks.

Cheers guys. :)

Hey all, I'm Jamie from Christchurch, New Zealand. I'm planning to do up a ke30 in the near future and am gonna be building a mild 5k to drop into it. The purpose of this post is so that I can find out if I should be using a single or twin sidedraft setup. I'm aware that either will do the job, but firstly I've heard that twin setups can be a pain in the ass and/or costly to tune and keep them tuned. And secondly is that a twin setup may be unnecessarily thirsty. (The main reason for this concern is I'll be on a student allowance and would like to keep the fuel consumption within a sensible range for a 1500cc motor.) I've got a PAIR of Mikuni/Solex 40mm sidedrafts with k series manifold, but because of the above mentioned potential problems, have begun to lean towards using a SINGLE 40mm sidedraft setup. The only mods to the 5k will be; A mild road cam, polished inlet/exhaust ports/intake manifold and almost-flat-top pistons. So to sum it up, what I need to know is: -Is what I've heard about twin setups being a pain in the ass/costly to tune a myth, or is it true? -Will a twin setup on a 5k use too much fuel? (in comparison with a single carb setup that is) -Will I be comprimising much power if I do choose a single setup over twinnies? Any help would be greatly appreciated, especially from those who have had experience with this issue. :( Cheers all, Jamie. :)