To those that have polished your intake manifold. . .

[Kingpin]

Did you ever get all of the dimples from the casting process to go away? I know sometimes with cast aluminum you can't, and it seems that in some places I'll sand/polish them away and more will surface. That's the problem some describe with cast aluminum and it's the issue I'm having. You'd never see it in pictures but to me it's annoying. Wondering if it's something I'll ever be able to get rid of or if I should live with it.

And just to whore out my progress :

[frankie gamez]

Looks sick either way!

[PrEgO CaNe]

wish i had the patients and skill to do this. love the look of polished intake manifold

[J-Ro]

Sweet! I'm doing the EXACT same thing. How did you get into all the areas around the injector holes and the fuel rail posts??

*EDIT* I know what you mean about the casting though. I think because it's a low-pressure sand cast, having the little imperfections appear is par for the course unfortunately.

[sivtecboi80]

I want to do this so bad i was just wondering this morning how i should do this. Did you guys do it by hand or use a dremel? What grit paper do you start off with and how do you bring it to a superbright luster? And I agree a polished intake manifold in our bay with a password jdm carbonfiber radiator shroud and some stainless braided lines coming off of the intake manifold and throttle body look phat as hell.

[J-Ro]

This is the process I've gone through so far:

1. 60-grit flap disk on a drill to get rid of the majority of the casting surface.
2. 120-grit flap disk on a dremel to further refine what the 60-grit did and get the areas that the last step couldn't.
3. 320-grit wetsand.

After this, it's just wetsanding until 2000 grit (and until your fingers are raw ) and then polish.

I'm thinking that those conical sanding drums on a mandrel might work for the tight spots? I haven't been able to find any though...

[bossman]

FYI,your IM will run slightly hotter after doing this....less surface area to radiate heat away....but it looks cool as shirt!

[atruhondagrl]

You should get it ceramic coated. It will reduce the temperature. I got my upper intake plenum ceramic coated and I want to get the lower one done now because I'm that impressed. Plus its all shiny and wicked looking under the hood.

[Kingpin]

Originally Posted by J-Ro

Sweet! I'm doing the EXACT same thing. How did you get into all the areas around the injector holes and the fuel rail posts??

*EDIT* I know what you mean about the casting though. I think because it's a low-pressure sand cast, having the little imperfections appear is par for the course unfortunately.

Yeah thats what I thought. Oh well.

I'm using a bit different process and am very happy I don't have to do this with a dremel, though gutting out the middle is work beyond a dremels capability as far as I'm concerned. I would not try it without air tools. Polishing can be done with a dremel but I wouldn't want to do it that way.

After cleaning out the webbing with carbide rotor files I started with 80 grit on a 2" disc mounted in my mini angle die grinder (yeah I'm using a compressor. A big one). That got rid of the casting marks and dings from my carbide tip. I'm using 80 grit polishing compound now on a combo of loose and sisal wheels mounted in my regular die grinder. I have 80, 120, 180, 240, 400, and 600 grit compounds. They do not seem to correspond directly to sandpaper grits because while the lower numbers cut very well, they do not leave the scratches that a similar sandpaper would leave behind. The image above is after a polish with 80 grit. It has worked well at removing the sandpaper marks and can remove casting marks too but it takes a little longer.

This is my first polishing project and so far it's going fairly smooth. I'd love a bench mounted buffer though. If I get into doing these for locals I will definitely be getting one.

[Kingpin]

I'm in a rush out the door right now but I'll post pics of the different wheels I've used so far. The loose wheels get into the tight spots OK but I'll still need some dremel size ones for the tighter areas.

[J-Ro]

^ Please do! Where did you get the compounds? I didn't even know you could get compounds that could cut that coarse. Maybe I've been doing this the hard way all along

[PrEgO CaNe]

^ now you've learned so when you do mine you'll be pro lol

[J-Ro]

^ That's okay, I'm usually my own guinea pig anyway

Just visited caswellplating.ca and ordered 5 greaseless compounts from 80-400 grit and a brown tripoli bar.... let's see if that speeds up the process!

[Kingpin]

I got mine from Caswell plating too. Good choice. Also check out there forums, I've picked up a few tips from there.

[sleeper101]

Originally Posted by Kingpin

Yeah thats what I thought. Oh well.

I'm using a bit different process and am very happy I don't have to do this with a dremel, though gutting out the middle is work beyond a dremels capability as far as I'm concerned. I would not try it without air tools. Polishing can be done with a dremel but I wouldn't want to do it that way.

After cleaning out the webbing with carbide rotor files I started with 80 grit on a 2" disc mounted in my mini angle die grinder (yeah I'm using a compressor. A big one). That got rid of the casting marks and dings from my carbide tip. I'm using 80 grit polishing compound now on a combo of loose and sisal wheels mounted in my regular die grinder. I have 80, 120, 180, 240, 400, and 600 grit compounds. They do not seem to correspond directly to sandpaper grits because while the lower numbers cut very well, they do not leave the scratches that a similar sandpaper would leave behind. The image above is after a polish with 80 grit. It has worked well at removing the sandpaper marks and can remove casting marks too but it takes a little longer.

This is my first polishing project and so far it's going fairly smooth. I'd love a bench mounted buffer though. If I get into doing these for locals I will definitely be getting one.

Yes this is good i agree you need more rpm I have a big 80 gal air compressor,dont even worry about trying to polish untill you have all the fine lines and pits out,it will not shine untill this happens the polish i got from casswell is the brick kind,mine took me about 12 hrs 2 hrs each day because i did mine with it on daily driver. Mak sureyou lay a blanket on engine to avoid mess as this is a very dirty and tedious job.

Good luck
Lee and when finished you will be about a pound lighter

[sleeper101]

Here ya go

[Kingpin]

Air volume is not my problem

[PrEgO CaNe]

can you just powder coat your intake manifold or do you have to sand it down first?

[J-Ro]

It is possible to powdercoat, but the rougher the surface, the greater the risk of offgassing underneath, a.k.a. bubbles. I tried doing a chrome powdercoat on the valve cover last winter but it didn't go well. I spent hours shaving it and prepping it, and what came out was basically identical to stock.... I don't know if I didn't bake it right or if it was just crappy powder. This winter, I'm going to do it properly