Intake and Valve Covers - Powder Coating
Mo and I have recently revived our "project car" and have a few relevant details to report. It is an 87 S4 Auto we bought months back and have gone through virtually all systems. It has been running (strong) for a week now and one of the areas that we took on was the valve covers and manifold. They were horrible. Brownish valve covers and chunks peeling off the manifold the size of silver dollars. Since we had everything else apart, we pulled the manifold and valve covers and visited an excellent powder coater here in Wichita, KS that I have had experience with before. After a little trial and error, we got to the final product, which is bead peening twice for prep (prep is all important here), leaving the inside of the manifold raw but peened smooth, and coating the inside and outside of the valve covers. Note that the bearings for the infamous flap must be either removed (difficult) or effectively masked off so no damage will come to them. We did this by inserting bolts and washers and then taping off with some tricky hi-temp powder coating type masking tape (they had this). Of course all interior surfaces of the manifold and side plates were masked. We (with help from this list, thanks Walt and David) determined that the inside of the manifold is too full of nooks and crannies for anyone to expect good coverage and eventually something would let loose. So we went raw. The inside surfaces of the manifold were eventually peened and smoothed out to be very clean...I was satisfied.
Cost was like $250 for the whole job...not too bad. There were dozens of colors (for you fancy guys) but we went with a pretty basic bright silver that looks great. Powder coating is practically bulletproof and I was surprised at the finish and how tough it was when we re-installed all the pieces. I don't think paint will ever be that tough.
Now I know that many are skeptical of the process, especially on interior surfaces like what we did with the valve covers. I asked our guys how many valve covers they have done, how long have they lasted, etc. We got very convincing replies like 10 years with no problems, etc. We saw their complete display of powder coated coil springs, leaf springs and many other items that see harsh duty. I had it done to all the metal on a boat seven years ago and it is still pristine, even on the cleats and rails. I am not too worried. I will do a follow up post when we take the covers off in six months to inspect them. Again, prep (removing ALL oil, dirt, sludge, grime and deposits) is key to the coating sticking properly. The first time with insufficient prep, the valve covers came back with a few spots like bubbles over any oil or grime that remained, you could work a bit and scrape some off with a knife. That's why they went back. Second time was perfect, baked on like a molded piece of metal with no loose areas.
Anyone wanting info on this can email me. As usual, proceed at your own risk, etc.
Marc White email@example.com http://www.goimi.com
928 Owners Club Charter Member http://www.928s4vr.com/928OC.html
PCA Member Wichita Region Porsche pix http://www.denari.com/marc
81 928 Weinrotmetallic/Black Auto 80,000 miles
88 928 S4 Schwarz/Maroon 5 speed 92,000 miles
87 928 S4 Guards Red/Black Auto 94,000 miles Project car with Mo
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