Author	[Modern View]
S.D.L. 07-24-2012 22:50:13 70.41.96.38 Report to Moderator	I have heard told to port/polish the intake manifold and then also have heard not to port/polish so the rough casting will creat turbulence and therefore mix the air fuel mixture better. Understood that there are many variables such as rpm and the amount of time it actually spends in the intake, but in general or under what circumstances would port/polish be good or bad. Just looking for everybodies opinions and possibly experiences with the subject. Thanks! [Reply]   [No Email]
Ole Johnny 07-25-2012 04:51:48 67.142.164.27 Report to Moderator	Re: Port and Polish Intake Manifold or Not? in reply to S.D.L., 07-24-2012 22:50:13   At higher RPM, it is much prefered to polish so the volume of air entering will have less resistance and thus more will enter. As for the rough surface mixing fuel and air better, the studys have shown that the rough surface in the runners will HOLD droplets and thus become 'smoother' by them selves BUT they will also cause restrictions. Use your simple common sense and visualize a running stream. The water is trying to get to the lake by flow. The rocks and sticks and falls restrict the flow and make the water churn and boil and such, but it slows down the water flow. If it is running thru a man made viaduct with no humps and bumps, it runs faster and more volume travels in the same given time. The more volume you can get in the cylinder the better. [Reply]  [No Email]
mEl 07-25-2012 04:43:41 108.10.128.243 Report to Moderator	Re: Port and Polish Intake Manifold or Not? in reply to S.D.L., 07-24-2012 22:50:13   Quoting Removed, click Modern View to see In my opinion the ports can be smoothed somewhat and gasket matching is helpful, the area immediately under the valve is the most important area, some heads have the guide protruding into the runner area, I get rid of that. IMHO at the rpm that limited classes run, real smooth large ports are probably not as important as the other factors in engine setup. Getting the compression up is the greatest single factor in hp gain. mEl [Reply]  [No Email]