Aluminum Intake Manifold Polishing

Aluminum Intake Manifold Polishing

First let me say that this is MY experience with polishing a dual-plane intake manifold for a MOPAR 440. Your mileage may vary.   And of course the standard disclaimer; I do not take any responsibility for your results. The views expressed herein are my own opinions and know the drill.

Manifold Polished

Let me start out my saying that it took just about every sanding and/or polishing tool that I owned to achieve this. I will tell you what worked and what I needed to improvise.

Buff Wheels

I bought the Aluminum Manifold Polishing Kit from Eastwood. I believed that this "kit" would contain everything that I needed to polish my manifold. I even went so far as to follow the instructions that came with the kit. Now, I have polished other things in the past; aluminum, steel, brass, etc. I have to say it took everything that I have learned from past projects to get this manifold looking decent. And I have to say that while the "kit" from Eastwood DID include some valuable pieces, it fell WAY short of being everything that I would really need to polish this manifold.



One of the most valuable tools that I owned and used extensively was my Black & Decker Mouse with the finger extension. I used this tool because the finger attachment and the regular sanding pad did a much better job of sanding flat surfaces. The "roll" and "taper" sanding tools that come with the Eastwood "kit" will leave an uneven surface when sanding on flat or slightly curved surfaces. The "mouse" worked very well for these surfaces. The only problem with the mouse is the available 'sandpaper' for the main pad and the finger extension. However, I did overcome this difficulty. I will go into greater detail later in this description.


Manifold Before

I cleaned the manifold with lacquer thinner before inspection.  I guess you could use carb cleaner but since I knew that I had 2 coats of lacquer on it, I figured the lacquer thinner would do a good job.  Besides, lacquer thinner is the "universal solvent" in my world.   

This is what I was starting with.  It is a 7 year old Edelbrock manifold that was clear coated with clear lacquer before it was installed...7 years ago.  It has yellowed quite a bit and the rough casting just was not 'cutting it' anymore.  Since I wanted to change the valley pan anyway, I figured that I might as well take a crack at polishing up this old manifold.  I had given the manifold 2 coats of clear lacquer before it was installed.  I am sure that helped keep the corrosion down to a minimum.  I am sure if I had not clear coated it, I would have been pulling the manifold and polishing it way before now.


Manifold Bottom- Before

BTW, if you can find one already polished...Buy it!  I did not find anything in my search and the Edelbrock is not offered polished for my 440.  I could not find any polished dual-plane manifolds for a 440 MOPAR.  But, you may get lucky.  I figured if I wanted one, I was going to have to polish it myself.  My results were not "perfect" but they are good.  This is not a concourse restoration or anything like that however, I do want it to look acceptable for the local shows and cruises.


I started by following the instruction that come with the kit. It provides a "grinders grease" (very useful to keep the sandpaper from loading up) which I used as per the instructions. You can remove the grinding grease residue with soapy water.  I used some from a spray bottle I keep handy.  I used lacquer thinner to remove the compound build-up, but I am getting ahead of myself here...  Regarding the sanding/grinding rolls and tapers that come with the kit; There are two slight difficulties with the starting procedure.

  •  First, the grinding grease collects aluminum debris and turns dark grey. And it sticks to the part you are trying to smooth out. This makes it impossible to see through the grease to inspect the work piece/path as you are sanding. The "upside" is that the grease does help keep the sanding rolls and tapers from loading up.
  •  The second issue is with the instructions. The kit comes with the following grit; 80, 240, 320. 80 grit is VERY AGRESSIVE! I did not realize just how aggressive until I cleaned the grinders grease from the areas where I was working and saw all of the gouges this stuff left in the surface...mostly right in the corners.

  TIP: Only use the 80 grit if you ABSOLUTELY HAVE TO! My advice is to START with 240 and see how it goes. I spent the better part of 50 hours removing the 80 grit gouges.

  TIP: Go Slow!  You can always take a little more material off, but it may be quite difficult to put material back on. 



After getting the surfaces as smooth as possible (I pulled out every tool that I owned including my Dremel tool) to get rid of the gouges.  I spent close to 50 hours smoothing out the gouges. After that I moved on to the "polishing" wheels and bobs.  The arbor that comes with the kit has one VERY MAJOR flaw.  There is a large metal "head" on the end of the mandrel.  After getting much too close and having to go back and sand out the gouges this arbor made, I finally wrapped electrical tape on the end, two full times around.  This helped a great deal in preventing further damage from this tool.  The trouble comes in when you are watching the surface that you are buffing and you are not really paying attention to how close the end of the mandrel is getting to an adjacent surface.


Mandrel wrapped with tape

 TIP:  Wrap electrical tape or even masking tape on any metal surface that could make contact with the work piece.  I even put masking tape on my electric drill (since I was using it for some of the buffing chores) 

Masking tape

The masking tape or electric tape may not last long if it makes contact with a surface while moving but it is MUCH better than making a dent or gouge in the already sanded or buffed surfaces.  Getting those small gouges out will take a great deal of time and if they are in the center of a large reflective surface, it is going to look very bad unless you go back and really work it out of the surface.


Remember, what you see is what you get. So, check the tape often and replace when necessary.  You will save yourself a great deal of misery in the long run.  I used at least two full wraps around the offending objects.  This provided a little protection against grinding a surface with the chuck.  Believe me, the feeling you get when you realize that you just put gouges into a surface that you had already buffed out will make your heart drop.

Die Grinder

I did make use of my die grinder for some things.  I wished that I had a compressor with higher capacity.  It would have helped.  I would not have had to use the drill as much.  The advantage of the drill was that it did not run out of air and the speed is adjustable.  But, the die grinder was easier to maneuver and had a smaller chuck to worry about.

Grinding 2

Here are a few more pictures of the manifold in the grinding stages;

You will notice the deep gouges in the manifold, especially in the corners.  I also have to say that this kit really did not come with anything to get into the small flat surfaces.  It was VERY difficult to get these areas looking decent. 

Grind 3

The trouble with the grinding rolls and tapers that come with the kit is if you use just the ends on a flat surface, you end up with a rippled surface.  I was able to get a 2" 3M roloc disk into some of the areas, and a few "Dremel tool" ends.  Some areas were too small even for those tools to be of any use.  The "mouse" helped in some of these areas but even it could not get into some of them.

Sanding 1

After about 50+ hours more sanding, I was able to start getting a decent finish.  Most of the sanding was done either with the "mouse" or by hand.  The "mouse" was indeed the most valuable tool that I used on this project.  You can work your way through 180, 220, and even some 320 grit on the mouse.  You have to have the "finger" extension attachment for the "mouse" to be as useful as possible.  There is also another tip coming up regarding the "mouse", but you are going to have to be EXTREMELY careful!!!

Sanding 2

You will want to spend some time sanding every area you can.  The more sanding you do and the smoother you can get the finish at this stage, the better your overall result is going to be.  I had some 400 grit wet sandpaper around and that was the first wet course I did. 

Spray bottle

I used a spray bottle with both water and a few drops of regular dish soap in it to work as a lubricant.  I actually find that this 'mixture' comes in handy for many things.  I usually keep one with soap and water in it and another with just plain water.  Any time you need to wet sand something, I have found it useful to use a spray bottle with soap and water.  This bottle happens to be from NAPA and holds about 1 quart of water.

Sanding 3

More sanding.  Another angle.  Just keep sanding.  The smother, the better.

DA Paper

Okay, so I mentioned that I had a mouse trick.  Well, I searched all over and could not find sandpaper for the mouse below 320 grit.  The mouse has a 'hook and loop' type setup so, I bought some 1000 grit DA disks at a local auto body supply shop. 
These disks have the "loop" side of the equation on the back of them.  I used a razor blade to cut them into the shapes that I needed for the mouse "finger extension".   Now, here is the thing.  This paper is not "wet" paper...and using wet paper with an electric mouse can be hazardous, so I am warning you ahead of time.

I used the spray bottle with soap and water and only sprayed enough water in the area that I was working to keep the paper from loading up.  Remember this is 1000 grit paper and it will load up quickly. 


Wet Sand

This is the manifold after 1000 grit with the mouse and 2000 grit by hand.  On to buffing and polishing.

Tripoli 1

This is the first course of buffing.  You use the Tripoli in this section.  Okay, so first rule.  Keep it clean.  Nothing will mess up what you are about to do than dirt and/or grit on the surface you are working on or on the buffing and polishing disks and bobs. 

Used bits

Next rule: Do Not Mix your buffs.  If you use a buff or bob for Tripoli, DO NOT use it for white rouge!  This is VERY IMPORTANT!  If you try to use white rouge on a tool that has been used for Tripoli, you will keep putting Tripoli grit scratches in your work.  So I use an indelible marker to mark the tools or keep them in a separate bag.  One bag for tools I used with Tripoli and one for tools I used in white rouge.

Tripoli 2

Here are some shots of the manifold after using the Tripoli.  You can see that the shine is starting to come up.

Tripoli 3

And another shot after Tripoli.

Polished 1

Cutting to the chase, this is after polishing.  This is done with the white rouge.  The white rouge is applied the same way as the Tripoli.  You will want to keep working the aluminum until you get the most 'mirror-like' finish you can get.  Since we are clear coating this manifold...what you see is what you get.

Polished 2

This is the other side.

Clear 1

This is after the clear coat had been applied.

Clear 2

Another shot after the clear coat.

     Here are some more pictures and explanations of a few other things that I used on the manifold.

Brush mounted in Vice

I used this brush mounted in a vice to clean or "spur" the tools like;


These polishing wheels. 

Buff bobs

And the bobs.

If you have questions, please feel free to e-mail me.  I will do what I can to help.