Removing the Valve cover for Polishing

[Oiluj]

Mike,

I did the cover on my previous Z. Granted, I had no deep nicks or scratches, but found that 1000 & 2000 grit w/lunbricant, followed up with a buffer wheel on a drill and polishing rouge did a great job.

[geezer]

This all depends on what results you want. If your valve cover already has scratches and nicks from dropped tools, etc., you need to be way more aggressive if you want those imperfections gone. You really have to try the sandpaper method yourself to see how well it works. You'd end up spending far too much time to get results that are not as good if you don't start out at the proper level of abrasion.

I agree Mike, It is sometimes nessesary to resort to a coarse paper to remove enough material so the nicks, gouges and deep scratches can be removed. It is just as important to sand out a much larger area well past the flaws, keeping the piece as flat/straight as possible so as to not end up with a wavy piece in the end. Nobody is wrong here, each part has to be assessed and the proper course of action taken. If you can start out with 1000 grit, you obviously have a very good condition part to start with.

[MikeW]

Exactly. The key is to start with the proper grade and move to finer grades in the smallest possible increment. Each iteration needs to completely remove all of the scratches from the previous. Absolutely, if you can start with 1000 then you're in great shape as your cover must not have any problems to begin with. You may have some scratches that you are willing to live with because you're not willing to go coarse enough to remove them completely. In that case you might end up with a very nice high polish in between all of the defects.

[Zs-ondabrain]

Same thing here. I started with a good dose of degreaser to make sure the grease did'nt affect the polishing. Then went to 1000 grit to smooth everything out, then 1500, then 2000 grit.

Then I used a buffing wheel on my bench grinder with a red rouge? to cut thru the scratches.

Followed by liquid aluminum polish to buff it all out. You'd be smart to use a deep crystal clear coat afterwards to keep the shine and luster. Make sure it's a hi temp clear coat.

You can wash out the buffing material and polish with warm, soapy water and a soft toothbrush for the cracks, before clearcoating.

As you can tell from the pictures, I've repeated the process on MANY of the aluminum items in my engine compartment. Schucks, NAPA, AutoZone and many other auto parts stores also carry Anodizing spray in Red, Blue, Gold and some other colors to really make it all come alive and maybe even match some real anodized items on the engine.

Dave.

The third picture shows the pulley and water neck after being polished (by me) then sprayed with the red anodizing spray, then clearcoated. As an offset to the blue anodized hose fitting.

[TomoHawk]

Instead of a clearcoat, tere are proper metal waxes (refer to Metalwax.com) to sustain & protect the finish. The only problem is that you can't get it at just any autoparts store, and if you ask a salesperson, they will show you car wax.

[7277]

100 grit is wa-ay too aggressive and will leave deep scratches. Better to use finer paper and more elbow grease.

i went with 100grit to start...it takes everything down to a common level, then 220, 400, 600, 1200, 2000, then to buff to a shine i used 2000dry. the clogged 2000 paper kind of creates it's own weird-sort-of-buffing surface..

[TomoHawk]

100 grit isn't all that coarse. I use 60-grit as a start on wood projects, then 220 and paint. On the Aluminum 100-grit should be fine, but will take a little effort on the next one or two grades up. Even a file can be used to take out scratches or dings.

[bobs77]

.....Followed by liquid aluminum polish to buff it all out. You'd be smart to use a deep crystal clear coat afterwards to keep the shine and luster. Make sure it's a hi temp clear coat.....

Dave, what aluminum polish and clear coat did you use?

Bob

[Zs-ondabrain]

Eastwood Makes or sells a Crystal Clearcoat that is specifically for hi temp polished aluminum applications. Just make sure that the surface is absolutely Clean of oil, wax and grease.

one is called "ZOOP"

http://www.eastwoodco.com/jump.jsp?itemID=5158&itemType=PRODUCT&path=1%2C2%2C607%2C1549%2C1560&KickerID=494&KICKER

They also have other clearcoats or you can use what I used, Dupli-color Hi-Temp clear. Eastwood also sells the new reflective chrome Powdercoating. here's a picture of it on some familiar items.

Edited November 16, 2008 by Zs-ondabrain

[bobs77]

Nice timimg--I just got the latest Eastwood catalog. Thanks for the info and pic!

[jalexquijano]

Question: once i remove, clean and polish the valve cover on my 240z will i need a new valve cover gasket and how tight should i fasten the bolts to avoid the heat drawn by the engine destroying the border of the cork gasket. I dont see this describe in the haynes manual. Should i also cover the engine camshaft and valves with plastic wrapping paper to avoid any insects or dirt getting inside while i am polishing?

[jonathanrussell]

I use an inch pound torque wrench to tighten to 51.6 - 86.4 inch pounds or 4.3-7.2 ft pounds. So, it is a very light amount of torque. I don't know of any fsm that references torque for the valve cover but these values are the same as the oil pan.