The title kinda sez it all, I caught a wild hair after working on my Cadillac all afternoon on Sunday and decided to have a go at polishing the intake. Now by intake, I mean the manifold itself, not the air intake. The allloy portion of the intake manifold has a pebble texture to it that isn't all that pretty and over time will probably accumulate dirt and crud. I started with a #36 grit 3M Sandblaster wheel on my right angle grinder to take the pebbble texture down to something I could sand really smooth. Next, I went to a #60 grit "finishing" wheel to get rid of any scrapes and scrathes left from my clumsy grinding technique. It was at this point that i discovered that Honda had left some imperfections in the mold for the intake manny as there are quite a few little "air bubbles" in the surface that had to be carefully filed away. I also took this opportunity to remove the casting marks in the tubes that make them look like two pieces instead of one. After the #60 grit wheel , I switched to hand sanding with #36 grit paper on a rubber block to get any grinder marks left over and to remove the file marks I had left after smoothing out the surface. Lastly, a hand sanding with #120 and #400 grit paper left a smooth satin finsh surface that looks like a welded tubular aluminum intake manifold going up under my painted engine cover! Some tips if you plan on doing this: 1. Remove the intake manifold from the car! Its a pain in the ass, but it makes life sooooo much easier. 2. If you aren't going to remove the intake from the car, mask the crap out of your front end, aluminum chips go every-freaking-where while you're doing this. I blew all of them off with compressed air to be on the safe side. 3. Get at least two of the right grit wheels for your grinder, you'll need them. The #36 is brown and the #60 is blue if you shop by color instead of grit # 4. I'll try to get some pics up today or tomorrow, I swear!

 

post picssssss

 

Pics would be awesome

 

Just not the same without pics..

Post some pics

 

[IMG]http://[img=http://img510.imageshack.us/img510/7015/015ra7.th.jpg]Pics for clicks?

 

[IMG]http://[img=http://img510.imageshack.us/img510/4127/021jv0.th.jpg]And some more, this one has the Caddy in it.

 

[IMG]http://[img=http://img231.imageshack.us/img231/4333/016jv6.th.jpg]Sorry to keep re-posting, I can't figure out how to post multiple pictures all at once. Bear in mind this is a work in progress, as it was getting dark and my hands hurt from sanding so I quit with work left to be done. The #3 tube (looking from left to right) is completely done the other three still have some left to be done. I think I may follow my own advice and remove the intake to finish it up right.

 

I really thing its gone to looks awesome when all done you must a very patient person..+rep

 

i just got done porting and polishing the inside of thealuminum section of the intake manifold. the outside is bad and the inside is of the same roughness.

 

^^Pscho Jungle Cat! Calvin and Hobbes FTW Damn, if the inside is as bad as the outside i'm wondering if it isn't that way on purpose! Something about inducing turbulence in the intake tract or something. If not then the sucker is gonna SING when you get it put back together. And I mean that in the best possible way BTW. The mold quality on the outside of the intake is pretty poor, very large amounts of flash on the joints and such, ick. How much trouble did you have removing your intake manifold Kylerwho? I looked at it pretty close and it looked like a real PITA! I wonder how much ExtrudeHone would charge me for one little ol intake mani?

 

it was real easy to get off.
take the manifold cover off with two bolts and speed screws.
take 3 bolts and two nuts off the aluminum manifold connected to the plactic manifold.
take off the egr hose and a screw to the left of it to remove a clip.
then there are 3 bolts and 2 nuts holding it onto the side of the head.
look for a diy about the hondata gastet for pics.
car runs great now. think im going to open it up a little more when i have time. air flows smoother over a glass surface than a rough one.

 

Well then I suppose my weekend project will be an interior and exterior polish of my intake manifold. Thanks for the info about the Hondata gasket, i wouldn't have thought to look there. And to all who are interested, I'll post pics on Sunday.

 

I've also heard that it is left rough for a reason. Grtpumpkin has it right. It is supposed to create a turbulance in the chamber for the air/fuel mixture to distribute itself evenly before combustion.

 

I'll reserve judgement until I get the mani off this weekend and see what it looks like. I may end up just doing a port match instead of a full interior polish, that is unless Honda has already done it for me! Either way I'll put up some before and after pics so you all can see what the hell we're talking about.

 

The sightly rough surface on the intake ports is to promote better fuel atomisation and also to promote fuel droplets to stay airborne... on the manifold side, you can go a lot smoother but you want to retain a certain degree of roughness (like 400 or 600 grit sandpaper!) it's tough to explain why but read this for more info!!

Cylinder head porting - Wikipedia, the free encyclopedia

and the entire article...

Cylinder head porting - Wikipedia, the free encyclopedia

Boundary layer - Wikipedia, the free encyclopedia

hope this helps!!

Marko!!

 

I imagine that the rough texture on the outside increases surface area which is an aid to efficent cooling. Its just too bad that it looks so UGLY After removing the aluminum portion of the intake, I decided to forgo the interior polish and port match as highly pointless ( Honda did a pretty damn good job of matching port surfaces already) and finished the removal of the rough exterior surface on the intake runners. I did this to the plainly visible surfaces only, mainly because getting the backside of the intake tubes would have been impossible with the grinder. I stepped up one grit level, to #600 for a final finish that is more than matte but less than polished. So far I have two of the four tubes "show ready" I'll put up some pics when all four are finished to my satisfaction. BTW, this ain't an easy, or quick mod to do, but if you have more time than money It is well worth the effort.

 

On a flow bench the best figures a bike mag got when trying to optimize an intake port path was when they just laid a strip of clay on the bottom of the port downstream from the valve stem. They could never duplicate that run.
The intake path upstream from the valve stem is probably much less critical.
At any rate ... Shine On happy buffers .. keep us posted on the results.

 

The outside is rough because the part is sand-cast aluminum. There's not much need to make the intake manifold look pretty on a base-level car.

 

Heres one of the finished product (for now) God knows what mischief I'll get into if it snows this winter...

 

And here are the rest of them. See Cojaro, just because the car came to me basic, doesn't mean I have to leave it that way.