90sBubblebutt

So been busy polishing my head and smoothing out runners. Didn't expand them at all just made them smoother and i think it looks great got some pics so here is an update on my build.

acmoc

Then just polish rite?
I did this with my TB, what tools are you using?


_MG_9830 by (ai), on Flickr

solomon93

You should never polish the intake side, only port it with rough grit. You have successfully decreased how well your head mixes air and fuel.

90sBubblebutt

Well my thought was if the intake is rough and not smooth the fuel would stick to the scratches and bad castings. Correct? So if the fuel is not making it to the combustion chamber because its stuck to the intake how well is it really mixing? how much is actually getting burnt instead of evaporating? This is just an experiment (trying to see if this will improve VE Volumetric Efficiency). Simple smother air flow more power its the simple things that add up. I used a dremel tool with stone wheels to smooth out the casting marks. There is a set of stone wheels on amazon for about 20 bucks they are equivalent to 120 grit sand paper. Then i use 320 wet then 400 wet 600 wet then polish cream. Most will say this does not do much and the reason why people say that is because this was a pain in the a$$ and not to mention it took about 25 hrs to complete. The best advise is patience. Now you can take the advise above I'm not going to say he is wright or wrong when i get the math done and i have access to a dyno so when all that gets done i will post and see what i find.

4drEF

Flow near the walls is slower than flow in the center.
If the walls are made smooth, the fuel in the slowed air/fuel mixture will start to stick to walls. Droplets of fuel will be introduced into the combustion chamber instead of atomized fuel in the air.
This is similar to what happens with a dirty or fouled fuel injector. Rather than spraying a fine mist, it sprays larger droplets.
Ultimately, your combustion burn will be worsened and it won't create as much power.

If the walls are made with an appropriate roughness (too much roughness has adverse effects as well) air will fill into the valleys of the roughened area making turbulence and "bubbles of air".
This greatly reduces the surface area that the main stream of air/fuel will flow will have with the walls.
The stream will ride on top of the turbulence rather than directly on the metal.
Far less droplets being formed = more atomized fuel making it into the combustion chamber.

acmoc

pretty sure you'll be fine OP

4drEF

... but as long as it's all apart.

acmoc

Port the manifold and throttle body whil'e you're at it