William A

I tried searching and didn't find anything that helped me, so forgive me if I am rehashing something that has already been vetted.

My '93 GTS has it's manifold off to replace the throttle sensor. I have been unhappy with my valve covers for some time, but it wasn't until I saw the underside of the intake manifold that I realized I in for a major loss of the finish.

I am trying to find the correct match, and the powder coat guys in my area are only close and not really in the ball park to my eye.

So first of all, is there a resource at Porsche who can tell us what was used, or at least tell us the source of the material they used? Although I don't know this, I would assume it would come from a source just like the paint does. It should have a code and everything that can either be purchased or matched (wishful thinking!)

In the end, my goal is to have my car look like it did when it left the factory. I certainly don't want some concours judge to tell me that the finish is not right (I have heard stories), but I want it correct just because that is how I am (use your own derogatory term to describe that, lol!).

I sure appreciate any help or guidance. I am sure doc Brown doesn't want my car taking up space in his shop while I figure this out.

As an aside, I know that Rob Edwards tried working with a local plating company and got a color that was somewhat close. I actually took my entire manifold to the same outfit in an attempt to match, and while they said much has changed in the 16 years since my car was made, the surface didn't appear to be prepped properly and it is no wonder the powder coat is separating. Ultimately, they said that the best bet was to go to Porsche and find out what they used otherwise I would just be chasing my tail trying to get all the variables right (color, tone, finish, blah, blah, blah).

If I can get this info once and for all, I am thinking that many of us will be saved alot of trouble in the future. I am willing to do the legwork if someone can point me in the right direction.

Thanks in advance, and look forward to your responses,
William

auzivision

I'm almost certain the covers were only painting in the factory, not powder coated.

My understanding the original paint was fairly silver and ages in the beige gold color.

I’m sure others around here know for sure.

dr bob

Talk to Greg Brown. A few locals have been working with him and his favorite parts finsihers to get the right colors in PC. We worked from a NOS intake side cover, and confirmed against the virgin unmolested underbelly of my intake. I have a set of covers and intake ready to go on the car. You are welcome to come look at them and see if it's what you have in mind. I'm in Glendale at the 2/134 intersection. The color is very close, within the normal range of factory variation. The sample piece we compared to is a little darker than what's on my car, for instance. I have 95k on mine vs the NOS part, so which is closer to the way they left the factory?

William A

Thanks to Dr. Bob, I will take you up on your offer.

I included some pictures taken today.

The top of the intake has more gold color, and the underside is more silver. The inside is like the top with more gold, and the black inside isn't grime but looks like the dark magnesium underneath.

So is the correct color what I suspect is the silver underneath? If so, I don't get why the inside of the manifold is the gold color.

Lastly, can it be confirmed that this is powder coated. The finish guys said yes, Greg Brown also thinks so. But I talked to PCNA and they referred me to a dealer who specializes in restorations (Stoddard in Ohio), and the guy there said he didn't think Porsche would have powder coated the finish of the intakes and valve covers.

Lastly, check out the abominable separation of the finish from the metal underneath. This is off a car that is 16 years old, with fewer than 45k mi., and and engine bay that is pristine. I have never used harsh solvents or abrasives. It is amazing to me that condition of the finish of the intake is this bad, discolored, and separating to this (or any) degree.

I am also surprised that the top of the intake is discolored anymore than the bottom. It gets less heat, and it's not like it is exposed to the sun or anything.

This whole thing puzzles me.

If anyone has any contact information of folks that can help, anyone who has successfully matched the finish, or if anyone can point in the right direction, I would be most grateful.
Thanks,
William

dr bob

I found on the intakes (some) and the cam covers (more) that there is a yellow chromate primer used under the silver. As the silver deteriorates, that yellow starts to show through, giving the illusion of a gold or maybe light champaigne color. My understanding is that the actual starting color is the same Zermatt silver that came originally on your fenders. But the intake and the cam covers came from different suppliers and have slightly different finish shades too. Different years, different batches of paint, different painters, different shades. Bottom line is that I don't think there's a wrong answer if you are in that range. The one thing that will get you points is the actual finish quality, as you pointed out in the original posting. That means that you want to use the minimum possible clear, and it can't be gloss finish. Looks real cool but it sticks out like a neon sign in an otherwise-original engine bay.

MrLexse

I don't think the original finish on any of these manifolds is PC. It seems to me that the GTS intake manifold was finished differently in the last few years of production. I've bead blasted four or five S4 manifolds in preparation to PC and the paint comes off pretty easily. Last week I got started on a 94 GTS manifold (21,000 miles on the engine) which was showing the same symptoms as yours. There is a thick blueish grey coating below the paint. This coating is present on the interior of the runners and seems to have been applied by dipping the manifold prior to finishing. It's thick enough to make me wonder if it was for temperature insulation (?). In either case, it is readily separating from the manifold underneath as is yours. This coating is not on any S4 manifold I have come across. I've tried to chemically remove it, bake it at 500 degrees, burn it off with a torch, and blast it with 60 grit aluminum oxide, to no avail. It is the finish from hell. The most success I have had was with a putty knife, getting beneath it in the areas where it was separating from the manifold. In the areas where it was not separating, it does not come off easily. You can get this manifold down to the bare metal by blasting, but it will take many hours. The cam covers, side covers and intake manifold all appear to be the same color, until you look very close. They are each a little different, which may or may not effect how you proceed. If you're going to enter a concours event, it might matter, but under normal conditions, you could finish them all with the same PC and it would look fine. I've gotten pretty close to the factory appearance with a color called "Shimmering Gold" by NIC Industries. I sent them a side cover for color matching, and they came very close. They'll do a custom color match for a fee and a minimum purchase, if you've got a greater case of OCD than me. If I get some time I'll post some pictures. Good Luck

Rob Edwards

Your experience with the GTS intake vs. earlier intakes parallels mine- My GTS intake was all but impervious to the bead blaster, while the GT intake stripped reasonably easier.

Here's the underside of my GTS intake, note the long cracks along the runners where the coating was cracking:




For posterity here's a shot of the powdercoat sample Greg is using on my intake and valve covers, compared to a new old stock intake side cover. The overall color is a little bit darker than the NOS piece but the finish sheen is pretty much spot on.

https://rennlist.com/forums/6450829-post140.html



The second pic shows the new factory side cover closeup, to give a sense of the sheen. The VC in the cover is a GTS cover, post- chemical stripping. The bead blaster wouldn't touch it either.

GregBBRD

According to the guy that strips my manifolds and valve covers, they are all powder coated. He claims that the finish is way too thick for paint. It also doesn't respond to paint strippers like paint does.

I agree that on the later cars, the coating got thicker, but I think this was to "hide" the cast appearance of the magnesium pieces.

William:

I forgot that Rob Edwards had pieces that were done. You should go look at his...the color is pretty darn close to that original cover...just a bit darker. You'd think it would be easy for them to make it a bit lighter, without messing with the sheen and general appearance....but I get usually get in trouble for thinking.

MrLexse

Rob your pictures aren't showing up on my computer as pictures, but rather as small boxes with a red "X" in them. Is there a setting I should change ?
Here are a few pictures I took of S4 manifolds which I powder coated, for color comparison with the original painted manifold and last is the GTS manifold which is in the middle stages

GregBBRD

That does look nice.

Rob Edwards

Lex-

My webserver is misbehaving right now - I took a couple of pics of the valve covers Greg had done and will post them when I can- they capture the sheen of the finish nicely. Consider this a placeholder.

Rob Edwards

dp

William A

Lex,
Thanks for your info and posting your photos. Looks like you are on the right track, I will try NIC tomorrow.
W

slate blue

I have only stripped one manifold, it is pretty time consuming, however I have done a bit of painting and the reason I raise that is that various parts on the 928 are stripped differently. The black window pieces IMHO are powder coat. The fellow who does my work told me how you can normally work it out. Paint thinners will normally strip powder coat, doesn't matter how old it is. It will wrinkle up and de-laminate.

He did say when he put my black pieces in his stripper designed for powder coat that it "the coating" was very tough. So even though the specialist powder coat stripper had trouble the paint thinners didn't after 25 years in the sun. Also powder coat doesn't have a primer so if the manifold has a primer maybe it is paint. I would put a bit of that hard coating in paint thinners and if it stays hard, it is paint. If it gets wrinkled etc, it is powder coat.

Greg

Rob Edwards

Here's the GTS intake after about 5 minutes of blasting in a commercial cabinet with aluminum oxide at high pressure. Tough stuff:




I know these pics are essentially worthless for assessing color over the internets, but here's a shot of a VC going on the stroker- color's a little too dark, sheen's pretty good.

I think that Lex's shimmering gold selection is a really good look too, certainly a better color match!




Closeup no flash





Closeup with flash