I think it was in the magazine, that I read Roys comments about the little green filter device on the Murena engine.
Actually Anders it was here on the forum I detailed this recently, in the topic 'Worklog of my car' started by RazorbackNOR. I was also going to repeat it again in the club magazine as it is quite an important feature, and the original was many years ago.
I didn't fit it when I converted the engine to sidedraught Webers, but I realize now why it is so important to keep a little vacuum in the crank case. I have noticed a higher than before oil leak.
For those of you who do not receive the excellent magazine of the MEC UK, the green filter has three connections. One going to the manifold, connecting to a calibrated stud (1mm diameter outlet), one going to the top of the cam cover, and one going to the airbox. Essentially it ensures that the crankcase is under a small amount of vacuum, and allows poisonous gases to be sucked into the engine, where they will be burnt instead of vented into the atmosphere.
Unfortunately, my setup does not allow for a simple connection of the vacuum side of the green filter, so I'd like to hear you guys, what to do.
As you will notice from the attached photo, my manifold - which is not a standard S-manifold, but a reproduction by Simon - has two vacuum stud connections. One on the right facing upwards for the headlight vacuum system, and one on the left facing sidewards for the brake booster. Since the webers do not have takeoff points for distributor vacuum, I have drilled in two thin additional connections in the two middle tubes of the manifold.
10 years ago, I photographed the engine room of a standard S, see the attached photo. Yes, that's yours Poul! Notice that the green filter is installed, but the vacuum connection is not installed. It is blinded off with a piece of hose and a nut.
What's the standard S-installation of this?
The standard 'S' Solex carbs. and the Dell'Orto DHLA carbs both have vacuum take-off points on each barrel. The standard 'S' had the green filter connected to one of these take-off points.
What would be a good way to connect the vacuum side of the green filter? I'm thinking I need to drill a hole in the manifold for a 1 mm stud, it will have to be in the leftmost tube of the manifold.
Thoughts, ideas?
/Anders
It would be possible to drill a couple of take-off points on the manifold, one for each carb. and link then together and then to the filter, but even just one would be sufficient. The Weber DCOE does have a casting next the the progression hole cover and the idle mixture screw, which looks like it would be the place for it to have a vacuum take-off but it was never drilled and tapped, except on the emission versions of the carb.
Roy