Early fe grey motor. 132 or 138?

[ardiesse]

Definitely aftermarket, and most likely one of these "economy-boosting" devices.  If you have a display cabinet, that's where I'd put it.  Replace it with a carburettor gasket, or even a smear of Silastic gasket sealant between bakelite spacer and inlet manifold.

Rob

[my8thholden]

hey doggy with a diamond ..never seen one of those ,I reckon after market product ,especially with elongated holes ,sort of suggests to me universal fit ,BUT WHY ..back in the day ,there was a lot of theory going around about fuel ,and carbies and combustion chambers ,and water injection  ,porting and polishing ,fuel and cylinder heads were blamed for lots of things or people just wanted things better ,a need was perceived and usually based on speed ,more power ,and get fuel economy at same time..roller rockers ,cross flow heads ,Yella Terra made a name out of it , a story , a history ,a workshop word ,
I am gonna say , that device was aimed at breaking fuel into fine droplets , we know today that theory back then they were on to something ,look at modern diesel cars ,diesel being a oil, with additives, actually by its very nature resists breaking into droplets ,but they achieve this by atomisation at high pressures ..it will be interesting to see if some technical info comes up on that device ,cheers Vern

[Harv]

Hmmm... not a filter per se with that hole in the middle. Lots of interesting tricks in old racers. Reminds me of this:

https://supertrarged.files.wordpress.com/2015/05/the-operating-limits-of-an-su-carburettor12.pdf

Dragon's teeth
At full throttle a significant fraction of the fuel will flow along the walls of the choke tube and into the manifold. It is possible to clamp a thin annular plate in that join, where normally a rubber insulator is fitted. The inner circumference of this plate is cut into triangular teeth projecting a few millimetres into the bore. Each tooth is bent in the air flow direction ca 45deg. The teeth lift the fuel film back into the fast moving, turbulent air flow so improving droplet formation. The trick is mentioned as 'dragon's teeth' in Maurice Brierley's book on supercharging motorcycles, and by Lenz (called a 'deflector ring', fig 5.31, cited above). This little-known device is simple to make and I suggest should be the first corrective measure to attempt should wall wetting be suspected.

Lenz' work is Mixture Formation in Spark-Ignition Engines, Hans P Lenz, 1992.

Cheers,
Harv

[Diamond Dog]

Thanx guyz. Interesting reading.   ( i wonder who wouldha e manufactured this ?) Surly not a one off item