| Author | Message | ||
     Sarodude |
Anyone have any ideas on what degrees of port roughness (uh, how do you measure that, anyway? grit?) work best with what port velocities? -Saro | ||
| Mikej |
That's all part of the "magic" that a lot of competitors don't like to give out. I have heard repeatedly that mirror-like is too smooth. | ||
| Jprovo |
Saro, You measure roughness in micro inches as a function of root mean squared height difference of the surface profile. You often see it in drawings with an RMS callout. Basically, the lower the value, the finer the finish. 125 rms would be a typical machined surface, or an as cast investment casting surface. 63 rms would be a reamed hole. 32 rms is a typical ground surface finish 16 rms is a honed surface finish. 8 rms is a polished surface finish. There are various methodologies to check surface roughness, the two I use are comparison to a roughness standard, and a machine called a profilometer that actually measures the surface roughness. There is much debate over port roughness. I'd probably make my ports in the 63-32 rms range on the intake and 8 rms on the exhaust. BTW, I think I've got a spare roughness standard somewhere if you want one. James | ||
| Jim_witt |
We do similar surface measuring profiles for our electropolished tubing in our gas distribution systems in the semiconductor industry. -JW:>  | ||
| Spiderman |
Rifle port the Intake |
