Aluminum Distributor Polishing

Aluminum Distributor Polishing

Here we are with another "Polishing" feature. I hope folks find this stuff useful.  This time we are working on a new distributor from Mopar Performance (via Jegs).

New Distributor

Here is the distributor from Mopar Performance (via Jegs) with the performance advance curve.  Now this is a fine distributor just as it is.  However, I have never been one to let "fine" be the last word.  I know that I can polish this unit up and give it some sparkle. 

This particular distributor is a challenge since the clips for the distributor cap are on the outside of the body and are 'staked in'.  You will see what I am referring to in some upcoming pictures.  Also, the vacuum advance unit will not detach without disassembling the entire unit, and I am just not going to take that path.

New Distributor

It will take a little more patience and a little more care, but I believe I can work around the clips and the vacuum advance.  Luckily I have a lot of stuff left over from the manifold polishing and I am sure I will be using some of it here.

New Distributor

This is a little closer look at the distributor.  You can see the casting leaves the surface of the distributor very rough and dull.  There is also a ridge that runs down both sides from the casting process where the two halves do not come together all the way.  This is called "Flash" and will need to be removed.  On the center right of the distributor in this shot, you can see the port that was left over from where the aluminum was poured into the mold.  That will have to get ground down as well.

New Distributor

This is a shot from the opposite side of the distributor.  You can see there is a seam just under the clip on the left side of the distributor.  You can see in the last photo and this on that the finish is very rough and very dull.  I have seen rougher but on my 440 Chrysler engine, this distributor is in the front of the engine so it gets noticed.

New Distributor

This is just a different angle where you can see the dullness of the finish.

New Distributor

Just one more from this side.  You can see the port that is used for filling the mold with molten aluminum.  That is the part that will have to get cut down and polished up.

Taped Up

Here I have taped up the parts of the distributor that I do not want to get compound or aluminum dust on.  I have covered the seal at the base of the distributor with a 'zip-lock' bag and some tape.  The top was done the same way.  I do not need an 'air-tight' seal on this distributor at this point.  That will change for paint but for now this works well.  I have started sanding in this picture.

Taped up

Here is another one where I have started to sand the surface of this distributor.  It will take some time but I am certain the results will be worth it.


Here I have started sanding and I have also started grinding the nub left over from pouring aluminum into a mold to create this casting.


Here I have been sanding and I have removed a couple screws and done a quick buff.  This helps show the high and low spots that will require more attention.  It also helps you feel like you are getting somewhere after a couple hours of taping, sanding and buffing.

Preliminary Polishing

This is after a little more polishing.  You can start to see that this unit is going to look nice when I am finished...providing I have the patience.

Polished 2

Here you can see a reflection...finally.  This took a few hours to get to this point.  I used the Black and Decker mouse with the 1000 grit sanding papers that I had made for the manifold.  I also have started polishing this with Tripoli.

Polished 3

Here you can see a spot that is still going to need work.  I have not gotten to this spot yet since it is so close to the vacuum advance.  I use the largest size buffing wheels that I can since this provides the least amount of distortion.  This is mainly due to the fact that there is more surface area with a larger buffing wheel and you are less likely to leave gouges in the surface.

Polished 4

Here you can see where the clip is 'staked' into the holder molded into the distributor.  I do not want to take a chance of breaking the tab or the mount off the distributor.  I am already sanding and buffing a $160 distributor.  I really do not want to break it.

Polished 5

These indentations are going to go unpolished.  I may leave them rough or I may paint them gloss black.  I have not decided yet so we will see.

Polished 6

Here is this section sanded down again.  You really have to work these parts to get them as 'mirror-like' as possible.  Now is the time to get all those deep scratches and dings out.

Polished 7

You can see that it is coming along.  I have removed the screws and am sanding in those areas.  Just buff, evaluate the surface and keep working it smooth.


Here is a tip;

I like to keep wheels and compounds together.  You do not want to use a fine compound on a buffing wheel that you have previously used a courser grit on.  For example, I do not want to try using white rouge on a wheel that was used for ebony or tripoli.  I would be wasting my time because the courser compounds will leave deeper scratches on the project.  I also like to mark the wheels with and indelible marker.  That way, I know what I used them for.  The smaller ones go into bags that are marked with the compound on them.


These are bobs.  They get into smaller places.  I highly recommend these no matter what size project, if you have any tight corners that you need to get into.

Polished 8

I was fortunate that after awhile this clip on this side of the distributor came off.  It made it easier to get in around it with the buffing wheels.  This is just before cleaning and final polishing.  You can see that the reflection of my thumb is quite good.


Here is the final buff on this part.  You can see a big difference between this and the first images.  The last compound I used on this was green.  It seems lighter than the white rouge and really does a nice job.

Buffed 2

I wanted to get this part as shiny as possible since it is going to be in the front of the engine.  I am also going to clear coat it which will drop the reflectivity by about 15%.  But it is either that or have to take it out every year and re-buff it.  Even Zoop-seal will only last a few years.

Before painting I will wipe it down one more time with lacquer thinner to get any remaining compound, wax, or fingerprints off of it.


This is the clear coat that I have had good results with in the past.  It is made for bare metal and seems to cling well.  This is the same stuff I used on the intake manifold.  It is available through Eastwood.

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