HomeSite IndexSearch Logo


Polishing the Valve Cover

By Matt Engelmann

Well I tried my valve cover polishing technique, though not in pure form, and boy did it turn out well.  My friend and I did it at his place over the weekend, and when we compared our valve covers to the polished lip of his Konig Tuners, I can honestly say the cover looked better (I'm sure the rims have a coating on them that protects from road nasty).  I can see my reflection in it, and it cost me about $20!!!!  So here's the way to do it:

Materials: -Assorted Sandpaper, from 240 to 800 grit (available anywhere) -Arbor buffing wheel for a grinder (ask somebody at Sears, they'll show you)       The 4" is good for drill, 6" for grinder. -If you want to use a drill, get a chuck adapter (again, ask the dudes at Sears) - Brown and Red buffing sticks (If you haven't got the hint, get it at Sears)

  1. If you are mechanically inclined or daring, remove the valve cover from the engine, otherwise leave it on, but you'll miss some spots [see notes below].
  2. Start sanding, use 240 grit until you don't see ANY dark little dots in the finish, just lots of scratches. This will take a while, and gets pretty messy.
  3. Go to 400 grit, start sanding.   Sand until the first rough scratches are TOTALLY gone and new, finer scratches are left.  At this point, you may see some little dots (dimples in the cast).  If there are a lot it will mar the finish, just like bubbles in paint, so go back to those spots with 240 again and then 400 until you're satisfied that they're gone.
  4. Now sand with 800 grit.   Keep in mind, what ever surface flaws (like deep visible scratches) that are there after you're done with this will still be there when you're done, so be thorough.
  5. Throw the buffing wheel on your tool and go crazy. Brown first, then red.

By now the finish should have an extremely high luster. From examining the finish over the past week, it seems not to be visibly oxidizing at all.   DON'T get tempted and polish your manifold heat shield, the aluminum is only an extremely thin coating, and it's mild steel under that.  It will rust and look way worse than it did before.

red_triangle.gif (202 bytes) Wayne Cox wrote about the procedure:

The procedure mentions possibly doing this with the cover on the motor. Just wanted to point out that you're gonna have bunches of aluminum grit and powder, which could do Bad Things to electrical stuff it gets into. Plus it probably makes a big mess in the engine compartment, which defeats the purpose the polishing job.

red_triangle.gif (202 bytes) Matt then responded with:

Wayne mentioned the possible mess involved in not taking off the valve cover when polishing.  It is true that the powdered aluminum goo gets on stuff, mostly your hands. If you don't have some cheap latex gloves to wear, you'll want to get some.  I draped an old sheet around my engine to keep the junk away, worked pretty well for me.  I thought due to my ability to loose and destroy small important parts that I shoud leave it at the large blunt buffing wheel.  All I know is from college chemistry, but I didn't think the aluminum would be detrimental, but if I wrong, please let me know.

Wayne's point holds true though, if you know how to take the valve cover off then you should do it, results are better too ;)