It's beuty on the inside that counts

[chameleonleather]

The wall was just cleaned up but no material was removed at the seal off. The butterfly was tapered to a .010 edge so only .010 of the original seal off needed to be maintained.

[chameleonleather]

Well someone should eventually bring up the idea of a boundary layer - and how a dimpled golf ball travels further than a non-dimpled golf ball, how sharks raise tiny scales in their skin when they want to swim faster, ect...

I don’t think this theory applies here. The air is being sucked in rather then an object flying through the air.

[rThor432]

Those theories apply here just like they do at the intake ports. Metric Mechanic has a nice article on the + & - of polishing.

[chameleonleather]

I agree that in the intake manifold it is better to have a rough surface to create turbulence but don't you want to get the air in there as quick as possible?

[mtechnik]

Nice work :)

[chameleonleather]

Can I see some port matched intake manifolds?

Before

[chameleonleather]

after

[rThor432]

I agree that in the intake manifold it is better to have a rough surface to create turbulence but don't you want to get the air in there as quick as possible?

From my brief understanding of how the airflow in the system works I believe that the low level air tumbling over the rough surface allows the air to flow better over it. The air sort of sticks to the polished surface. Hard to put into words, but MM says it best. I understand the concept, but it's not my field. If you really care check out their website. And they've got pictures!

[Jand3rson]

This should get interesting...

[der affe]

you didn't go deep enough into the intake to begin with. you just kind of made a funnel there. you need a less abrupt change in the manifold to the head.

no, you are not helping things with your polished throttle body. you would benefit from taking it and running a cross hatch scotch brite pad through the work you just did to give it a micro finish instead of the shinny one you have there.

[george graves]

Disclaimer: I'm in no way an expert on this.

Imagine that smooth surface under a microscope - Now, imagine a rough surface.

As the air flows over the rough surface, the tiny, tiny bumps/ridges create little tiny balls of turbulence on the surface. They end up acting as tiny bearings, rolling along the surface, allowing the majority of the air to flow with less drag.

With the smooth surface, all you have is drag.

I know - it's totally counter-intuitive, but that's how things work.

Of course its more-or-less academic, unless you're building rocket parts or something.

[chameleonleather]

Well I have now read the MM article and it's very well written. I did notice a positive difference after having it done. Now could there have been a better result if some perfect grooves where machined in, possibly. I will give that a shot when my head gets rebuilt with another throttle body. I agree that the manifold did not go high enough, only had 4 hours to polish up the throttle and open up the intake before installing it for the SD autox next day.

[kid325e]

Either way it's a clean throttle body.

[Fidhle007]

Any advantage you're feeling is simply from cleaning the moving parts in the throttle body. The work you did to the manifold will probably be a disadvantage, you've created a low pressure zone right in front of the valves.

[george graves]

Now could there have been a better result if some perfect grooves where machined in, possibly.

You don't need to machine in perfect grooves. The stock texture will flow better than your polishing work. If anything, you DECREASED air flow. But it sure looks pretty!