Some recent projects on my ’71 911:
PAINTING STOCK MUFFLER
My muffler was looking a little shabby, with peeling paint and light surface rust. I researched the correct muffler colour and finish in order to replicate what the factory did, nothing better, nothing worse. I was not willing to remove the muffler in order to paint it – too much hassle – so a brush-on finish was required, which, it turns out, is all the factory did (see below for more detail).
Many early 911 fans suggested the exhaust grey from the Eastwood Company. Following the instructions, I scrubbed the muffler with a wire brush, followed by sanding and then thoroughly degreasing it. Eastwood recommends applying it with a foam brush. It goes on VERY thin, replicating the thickness of water. As a result, multiple thin coats were required, with all coats needing to be applied within one hour.
WARNING: The fumes are very strong, so it’s critical that you have good ventilation.
I let the paint dry for a few days (24 hours recommended), followed by taking it for a drive for 20 minutes, bringing the engine up to temperature. The finished photo is after 3 months of use, including getting caught in a rainstorm.
I’m very happy with the result, as it closely resembles the factory exhaust finish. My reference was a photo that my friend Dave Conklin took of 713 mile 1970 911 S. Note the crude finish on the muffler. In fact, you can see where the factory technicians took a brush of gray paint and brushed it over the dirty hand prints after installing the drivetrain. The yellow/brown goo is the Cosmoline applied by the factory to prevent rust. Some of it spilled onto the front side of the muffler once the engine got hot and was driven down the highway. I wasn’t brave enough to replicate that mess!
Actually, comparing my muffler to the original, I may have indeed over restored it. 
Another mistake many people make is to yellow cad plate the muffler straps. As you can see by the 713 mile car, that is also incorrect – it was all painted gray, which I replicated.
LEAKING VALVE COVER
Like their ancestors, the Volkswagen Beetle and Porsche 356, the Porsche 911 engine is a known leaker. Despite the fact that the engine in my 911 is original and has never been re-sealed/rebuilt in its 56,000 mile life, it only has one leak. Which is why it’s so annoying, because I’m so close!
In Porsche’s obsession with keeping weight down, especially in the rear of the car, they used magnesium for all four valve covers in the early cars. My upper right valve cover leaks a bit. Not a lot – I never have to top up the oil between annual oil changes – but enough to annoy me. The valve covers are prone to leaking because, being magnesium, people tend to over-torque them, which causes them to warp and leak, which causes people to over-torque them even more, leading to an ugly downward spiral.
I tried an alternate valve cover, but it leaked too. So I removed the upper right valve cover, placing it on a flat surface, the butcher block on my workbench. A large piece of glass works well too. Write in pencil on the valve cover sealing surface, and then carefully sand back and forth, up and down and side-to-side, until all of the pencil is evenly removed. Repeat the process a few times. The pencil ensures that you are evenly sanding the surface and don’t end up with any high/low spots.
After doing all that, it still leaked. I’m not convinced that it’s the valve cover, and will continue investigating. Most friends have told met that I’m tempting the Porsche Gods by trying to make it leak free, especially with a 38 year-old engine; the moment it becomes leak free, it will explode. I haven’t given up yet…
