Aluminum Intake finish
 

I have a perfect 472 intake manifold for my Z. Looks like someone painted it and the finish is very bright. What is the best way to properly finish it? Bead blast and leave as is?

Re: Aluminum Intake finish
 

Do not bead blast. Wrong finish. If it has been muffed up all ready you might want to consider Jerry MacNeish and re-skinning, that is close. Valve covers and intakes were not smooth and shinney. Most of the time they looked weathered when new.

Re: Aluminum Intake finish
 

Does anyone know what the reskinning process actually consists of? Is it a burnishing process where the intake is shaken around in a tumbler, or is it shot blasted, or what? Looking to do the process myself if anyone can clear up the mystery.

Re: Aluminum Intake finish
 

I didn't think you could really "reskin" an Aluminum intake manifold?
But a process close to it in finish is replicated using Walnut shells.

Re: Aluminum Intake finish
 

Are you telling me I have to go to Sam's Club and buy a Paul Bunyan sized bag of walnuts?

Re: Aluminum Intake finish
 

...I had my 70 LT-1 manifold STEEL shot blasted(just like when they were mfg at the foundry) at a place that rebuilds Aluminum mostly japanese cylinder heads......not positive but a "Wheelabrator" brand or similar type of machine that they used to run heads thru on a conveyor belt like idea was used....They steel shot is only used on aluminum parts and wasnt contaminated with ferous metal or grease to get into or on intake or my Muncie case.....I'll attach several pics to show you examples of my intake, muncie case, AND muncie DIE-CAST PIECES which I had vibratory/tumbled in ceramic stones with a detergent/chemical cleaner

Chuck Sharin Seattle

THE FOLLOWING IS A STATEMENT FROM JEFF BETZ WHO CURRENTLY IS AN ENGINEER WITH DAIMLER-CHRYSLER.....previously with G.M. Jeff supervises in the plant where engines are built.

"Guys, I'm a design engineer that has worked with many cast iron and aluminum parts, and SAND CAST parts DO NOT have any type of skin on them from the foundry. Chuck is exactly correct when he states a "Wheelabrator" brand cleaning process (or similar version) is used to clean the sand off of a cast aluminum part when it goes thru "shakeout" which is the process of removing the core sand and green sand from the casting process. The type of media used may vary among foundrys, but they are all cleaned using an abrasive. To duplicate the "as cast" aluminum intakes may be a trick, because we need to correctly match that intake as it came out of the shakeout line of the foundry. It's anybody's guess today as to what media was used, and I'm sure that varied from month to month and foundry to foundry.
DIE CAST aluminum parts are a different story. A die cast aluminum part gets it strength from the outer SKIN that forms against a permanent cooled mold, very different from the sand used in a sand casting that is recycled/trashed after each part. Transmission tail shafts and distributor housings are typical DIE CAST parts. Today, some parts are a mix of a permanent external mold with internal sand cast cores."

http://img.photobucket.com/albums/v4...ls/IntakeA.jpg
http://img.photobucket.com/albums/v4...hotBlasted.jpg
http://img.photobucket.com/albums/v4...ase1970Top.jpg
http://img.photobucket.com/albums/v4...eSideCover.jpg
http://img.photobucket.com/albums/v4...ailhousing.jpg

Re: Aluminum Intake finish
 

I use plastic media (melamine) in the blast cabinet. Sand and glass are too aggressive and leave the item too shiny.

Re: Aluminum Intake finish
 

Darren,

Let me know what technique you used on your 472, to get the correct factory finish. I also have a nice 472 intake on my 69 Z that is really polished and needs to be dulled up a bit.

Re: Aluminum Intake finish
 

try easy off "fume free" lemon scented oven cleaner.it works very well and gives the aluminum a nice factory finished look.i cleaned my edelbrock TR-1X tunnel ram with it and it looks great.the aluminum has a light dull gray finish to it after cleaning with oven cleaner. spray the intake with the oven cleaner getting it completely covered in the foam.let it sit now for a half hour then rinse with water and use a toothbrush in hard to reach areas.this process may need to be repeated twice but you'll be very happy with the results https://www.yenko.net/ubbthreads/imag...ins/3gears.gif

Re: Aluminum Intake finish
 

Worked on the intake today. Here is how it came out. I know it is hard to tell in the pictures but I will post anyway. This shot is half the intake blasted. The blasted half is the distributor end to center. The other side was really shiny.
http://img.photobucket.com/albums/v3...6-3644_IMG.jpg