Oddities.
Here's one for the Porsche historians out there. We found a pair of original Porsche boxes marked 901.113.904.00 in our shop. According to our research, they are part of a Federalization / Emissions update kit for the air-pump equipped 1968 911. The parts include a General Motors-sourced valve, a breather filter, as well as a few brackets and hoses.
We're not quite sure what to do with these two little critters, but here's a question for you folks—in the enthusiast's quest for the ultimate in originality and concours scores, are you going so far as reinstalling all of the original anti-smog equipment on your vintage 911s? At what point does driveablity and reliability trump the concours points?
In theory, air (or smog) pumps add air into the exhaust stream just past the exhaust valves. This increases the temperature of the exhaust gas and helps burn off any extra fuel leftover after the combustion process in the engine. This reduces the emissions output of the engine with only minimal effects on performance. Sadly, engines with these air pumps attached often suffered from cracked heads due to all of that extra heat in the exhaust tract.
That said, many of these air-pump equipped cars are over 40 years old now and are out of the typical window for emissions testing and compliance, so it really just comes back to whether or not you want your car really to be as it was delivered from the factory in 1968. Even for nuts like us, it would be a stretch for us to put an air pump on a 911 during a restoration.
