[Polishing]: Valve Covers
Thread Starter
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
[Polishing]: Valve Covers
Ok guys, I finally got around to taking one of the magnesium valve covers down to the bare metal with a die grinder and wire brush attachment. The casting quality is CRAP on these things. I can see why GM had loaded them up with primer and paint to hide it.
What would you suggest I do to try and take out as many pits as possible?
Thanks!!
p.s.
They started like this...
[Modified by scorp508, 9:13 PM 1/26/2002]
What would you suggest I do to try and take out as many pits as possible?
Thanks!!
p.s.
They started like this...
[Modified by scorp508, 9:13 PM 1/26/2002]
Elite Torch Red Member
Joined: Sep 1999
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
Cental/South NJ Events Coordinator
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St. Jude Donor '03-'04-'05-'06-'07
Re: [Polishing]: Valve Covers (scorp508)
Bondo!
I'm guessing you're leaving them polished?
Looks like you have a lot more work ahead of you.
You are right, I remember Gordon Killebrew talking about how they couldn't get a good finish, so they "loaded" it up as you said to hide the imperfections.
I'm guessing you're leaving them polished?
Looks like you have a lot more work ahead of you.
You are right, I remember Gordon Killebrew talking about how they couldn't get a good finish, so they "loaded" it up as you said to hide the imperfections.
Le Mans Master
Joined: Feb 1999
Posts: 5,381
Likes: 0
From: Pineville, Louisiana
Re: [Polishing]: Valve Covers (Mr Mojo)
It may be more than you want to spend but a new set of valve covers is gonna save you lots of time and will probably look better than anything you can do yourself. :smash: You already have lots of work in those things now :eek:
Pro
Joined: Aug 2000
Posts: 519
Likes: 2
From: South River N.J.
Re: [Polishing]: Valve Covers (scorp508)
Forget it Scorp. Your better off getting an aftermarket set already polished or chromed. Those castings were never intended for anything but paint. To bad you put all that time into them already.
Le Mans Master
Joined: Aug 2000
Posts: 6,227
Likes: 0
From: Corona CA
Re: [Polishing]: Valve Covers (scorp508)
Yep! That's exactly how bad mine look. I tried to take them to a shop to be polished. They took one look and laughed at me. I ended up stripping and painting.
If you really want them to look good, get the aftermarket.
If you really want them to look good, get the aftermarket.
Thread Starter
Team Owner
Joined: Mar 2000
Posts: 83,383
Likes: 87
From: Boston, MA
Re: [Polishing]: Valve Covers (Danah92LT-1)
Scorp508, do what I did with mine. Find a box and put them in the garage and go and buy these from Chevey Perf. for $116.00.
Come on guys. I know I've seen a bunch of L98 owners with the stock covers polished. Somebody must know. Am I going to just have to start with some rough sandpaper and work my way down. :)
I'd rather not spend money on MORE valve covers. These are just a nice side project that I can hack away at when I have time. :) Plus it is nice to say "Yeah, I did that!" :yesnod:
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Le Mans Master
Joined: Aug 2000
Posts: 7,760
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From: Lost in the mountains of TN
Re: [Polishing]: Valve Covers (scorp508)
Looks like you need to grind some more. Then start with 80 grit and work your way up. But some of those pits are pretty deep.
I dont know if I would grind them as far that is needed to get them out. How thick is the valve cover?
I dont know if I would grind them as far that is needed to get them out. How thick is the valve cover?
Race Director
Joined: Aug 2000
Posts: 14,130
Likes: 7
Cruise-In II Veteran
Re: [Polishing]: Valve Covers
Scorp,
I had the same EXACT problem with my 86 covers...They were dull,brown and peeling so I stripped them down to bare metal.I had pourous pits, geographical map-like grand canyons running through the casting and decided to buy new covers.
I got mine cheap from http://www.paceparts.com but Jeff Kopp can get you new ones cheaper if you decide to go that route.
They are the 88 and up style and use the screw on oil cap,not the twist-lock on and come with a new emblem as well.Identical except for the oil cap.Btw,this newer cap design doesnt leak oil like the older versions did,a PLUS.
One side was like 65 bucks and the other was 72 or so.
Just letting you know in case you decide yours cant be polished nicely due to imperfections.
It seems some castings came out better then others.
Good Luck in what you decide.
:)
I had the same EXACT problem with my 86 covers...They were dull,brown and peeling so I stripped them down to bare metal.I had pourous pits, geographical map-like grand canyons running through the casting and decided to buy new covers.
I got mine cheap from http://www.paceparts.com but Jeff Kopp can get you new ones cheaper if you decide to go that route.
They are the 88 and up style and use the screw on oil cap,not the twist-lock on and come with a new emblem as well.Identical except for the oil cap.Btw,this newer cap design doesnt leak oil like the older versions did,a PLUS.
One side was like 65 bucks and the other was 72 or so.
Just letting you know in case you decide yours cant be polished nicely due to imperfections.
It seems some castings came out better then others.
Good Luck in what you decide.
:)
Burning Brakes
Joined: Sep 2001
Posts: 1,162
Likes: 76
From: Sumter, SC
Re: [Polishing]: Valve Covers (scorp508)
I was thinking of doing the same. I've got a spare set and wanted to polish them too. Even if I just paint them, what is the best way to strip them? I was thinking of bead blasting instead of wire brush. Has anyone tried that?
Scorp, you'll have to go with a course paper to sand and work your way down. Do the imperfections go through the casting like vaines? If so, you'll only uncover more imperfections as you sand.
Scorp, you'll have to go with a course paper to sand and work your way down. Do the imperfections go through the casting like vaines? If so, you'll only uncover more imperfections as you sand.
Burning Brakes
Joined: Jun 2000
Posts: 913
Likes: 17
From: Chatsworth, Ga.
Re: [Polishing]: Valve Covers (scorp508)
scorp508, I had the same kind of valve covers as yours. Early 92 LT-1. That is why I changed them. These new ones will fit your L98 center bolt covers. :flag
Thread Starter
Team Owner
Joined: Mar 2000
Posts: 83,383
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From: Boston, MA
Re: [Polishing]: Valve Covers (Danah92LT-1)
scorp508, I had the same kind of valve covers as yours. Early 92 LT-1. That is why I changed them. These new ones will fit your L98 center bolt covers. :flag
Le Mans Master
Joined: Nov 2000
Posts: 7,391
Likes: 3
From: Chandler AZ
Re: [Polishing]: Valve Covers (scorp508)
Scorp,
As per our previous discussions I know you know the older L98 cover mag castings were crap as well. I bought 2 sets and put the best 2 together. They were still bad but I had them powdercoated... along with the plenum and runners. I'm not sure PC is an option for you or if you prefer the polished look. PC does not cover up the imperfections very well but with all the harnesses and hoses in place one doesn't really see the sides of the covers too much anyway... I know... but you'll know its there:D Powdercoating WILL, however, protect the magnesium from further damage. Mine has been done for over a year and stood up to an Arizona summer with no problems whatsoever. Exposed magnesium will "grow" a layer of magnesium oxide ("rust") on top of it over time. We've talked about this for over a year and we both have seen several members put ALOT of work into their stock covers to make them look as good as you want. Opinions vary on the upkeep. Its possible as you know... but it looks like you have to take considerable more material off before you have a smooth surface. My suggestion would be to look around boneyards for another stock set and see if you can match up a good pair... if you prefer to stay with stock covers. Good Luck :cheers:
Drifting
Joined: Nov 2001
Posts: 1,498
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From: Bucks county Pa
Re: [Polishing]: Valve Covers (billreid1@***.net)
Thanks for the post. I was gonna try to polish mine to match the intake when i do that. But now ill shop around for covers. I really thought they were nice under the brown :eek:
Team Owner
Joined: Apr 2000
Posts: 27,818
Likes: 8
From: CT
Re: [Polishing]: Valve Covers (billreid1@***.net)
when the time comes(intake gasket replacement) I am going to either powdercoat mine black or go with LPE covers. If spending $300 on a set of covers isn't your cup of tea...go with powdercoating. I think it'd look especially nice on your yellow car.
Melting Slicks
Joined: Apr 2000
Posts: 2,793
Likes: 46
From: Elizabeth City, NC
Re: [Polishing]: Valve Covers (IndianaKoko)
Scorp,
Its not impossible, I did the ones on my 88 back in the day. It was time consuming. Just takes alot of sandpaper. I started with 60 and then went to 200 and so on until I got to 1500. Get to work, should be done by the time the warm weather gets here.... :D :D
Its not impossible, I did the ones on my 88 back in the day. It was time consuming. Just takes alot of sandpaper. I started with 60 and then went to 200 and so on until I got to 1500. Get to work, should be done by the time the warm weather gets here.... :D :D
Team Owner
Joined: Oct 2000
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St. Jude Donor '03-'04
Cruise-In 1-2-3-4-5 Veteran
Re: [Polishing]: Valve Covers (LPDesRoche)
It's going to get frustrating. You know that as you polish a casting, you just expose more voids.
Also, I notice that no one has mentioned the propensity of magnesium to ignite and burn at 2000 deg. F? I'd try to do the work in a shop with a D-class fire extinguisher...:D
Also, I notice that no one has mentioned the propensity of magnesium to ignite and burn at 2000 deg. F? I'd try to do the work in a shop with a D-class fire extinguisher...:D
Thread Starter
Team Owner
Joined: Mar 2000
Posts: 83,383
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From: Boston, MA
Re: [Polishing]: Valve Covers (Matt Black)
Also, I notice that no one has mentioned the propensity of magnesium to ignite and burn at 2000 deg. F? I'd try to do the work in a shop with a D-class fire extinguisher...:D