My 383 build is coming along well, cam and timing chain is in and degreed...but thinking to the future about my manifold. I have a friend who has a Performer RPM for minimal $$, but it is satin. The rest of my parts that i'm using are polished (accessories, bolts, themostat housing etc.). My question is can I polish a "satin" RPM to make it match the rest?? If so how would I do this?? Thanks.

Polishing that manifold would bear a bear... co many nooks and cranny's...

To polish alluminum, you would first grind off all the casting roughness, then sand with progressively finer paper to revove the sanding scratches. Once you get down to 1000-1500 grit paper, you'd use a polishing wheel, first with a coarse, then a fine compuond to bring it to a mirror finish.

I've done this on large, flat things like old alluminum valve covers and on small cast stuff, doing it on a manifold is mind bogling.

I know it'll be time consuming, but the price is pretty good( A new one is at least $230+shipping) . I dont mind putting in the time if it will work in the end. Whats a good grit to start with?? 120?

Star as fine as you can go... try 220 first. You'll need some quality tools and a die grinder. The cheap roll ones won't work, they can't handle the rpm. you might even look at a selection of carbide cutters to start with. It's gonna take FOREVER... that's whay they charge so much.

You might think about ebay'ing the nmanifold you have for a hundred, and putting that towards the one that's all ready polished...once you start grinding on it, there's no going back.

I repolished my old m/t valve covers not long ago, took 8 hours of work to shine em up, and these are FLAT and SMOOTH all ready, just wetsanded with 400 and up to get the oxidation off, then polished.

NRMEDIC984,
I have done quite a bit of polishing including intakes. While it is time consuming (you are looking at about ~25-40hours), it can be done at home. What you will need is a die grinder (or two), You can save yourself a lot of trouble if you use grinders grease, and cartridge rolls. This will save you a lot of time (makes it smoother faster) and will be easier to polish.

Check out Eastwoods and I HIGHLY suggest you buy a manifold polishing kit. If you don't want to get that get a head porting/polishing kit from Summit (it will have the sandpaper rolls), you have to have the rolls to get into the corners.

Now if you want to do the whole thing by hand (meaning no die grinder) you will be in for one heck of a time. It can be done. You will want to wet sand from start to finish. I would not even think about doing it by hand. It will take you weeks and you will wear your fingers out.

If you decide to do it let me know and I can help you through it. Just be ready to put in some hours.

You do not want to grind or use a carbide on it, if you do it will make more work for you. I can tell you what grit rolls you need if you want to buy them individually (might as well buy the kit).

I guess its a toss-up. The kit is $60 plus borrowing a die grinder. Like i said I dont mind the labor but i guess it comes down to it being cheaper than a new manifold.. It would be good polishing experience, LOL. Thanks for the info...

I forgot to mention you can use Scitchbrite pads on the die grinder for the larger areas that you can reach with it. It also helps to have a right angle die grinder as well. I typically have three die grinders out, one with a Scotchbrite, one straight with a snading roll, and my angle die grinder with sandpaper. You can pull it off with just one it will just take a little longer while you are changing back and forth. You can start with the course Scotchbrite to get it smooth, then switch to the green. If the casting is not real rouhg you can sometimes just start with the green. You can use grinders grease with the Scotchbrite pads as well, it helps make the surface smoother and helps the pad and paper last longer (kind of like wet sanding).

Looks like i'm gonna try the polishing route with the eastwood kit seems...it's a reasonable price. thanks for all the advice.

I use an old abrasive pad on my die grinder for rough polishing. Just be sure the pad is smooth enough to not cut into the metal. You should see fine swirl marks and not deep scratches. Fine scratches are going to be there and you can polish first with scotchbrite pads then fine steel wool then wet sand paper progressively finer. To get real smooth there's jeweler's rouge and other very fine abrasives. I've heard of compounding but finishing stuff.

It doesn't matter how you do it as long as you don't take off too much to start with then get progressively finer each step. An electric grinder with polishing wheel works well unless you can regulate your air to your die grinder.

You can buy a polished one from 125 up new. Just look around eBay.

Plus sit yours down on the engine and look at it for a few days. It may start looking good thinking about all that polishing. One or two pieces with factory patina aren't a bad contrast.

You can also glass bead it then consider powder coating or that new finish. Sorry can't remember it.

Good luck and remember. All this work is fun!