Guys, testing air slide valve prior to putting engine back together . Have put in small container of boiled water and the piston moves from about a 5mm gap to about 1mm when "closed"...is it supposed to be fully closed ? ie 0mm .( Has not been used for about 14 years after engine seized )
Cheers, Simon
The curse of a lazy auxiliary air valve?
Some disorganized musings:
Over the eons I have attempted cleaning a few AA valves, with little success.
This did not involve total disassembly. In the “good old days,” lazy AA valves were inexpensive enough to typically warrant a new replacement valve. Over time, the valve’s piston can certainly get gummed up, corroded and even galled. Nevertheless, I do not think this is the primary cause of the valve being lazy, especially since I remember testing several brand new (clean and unworn) valves that failed to completely close. Instead, I wonder about both the spring that tensions the piston assembly and, more important, the brass bulb containing the magical plasticine substance that causes the piston to move in its bore.
Examining the attached dissection photos of a two similar AA valves, it seems that
carefully crimping the brass bulb "might" displace some of the bulb’s volume and force the piston higher, sealing the valve as intended. I have not carefully looked at one of these valves in quite some time. I do recall that some (but not all) of the bulbs were crimped. It is unclear if the crimping is a byproduct of the assembly to retain an inner brass cylinder/bush or it has some other significance. As I presently do not have a suitable test subject, I merely present this as an untested theory for someone who does have a suitable test subject.
Notice also that there is a linkage between the bulb and the piston. If the valve were to be disassembled, it is unclear whether that linkage can be “adjusted” by bending/straightening or by possibly rotating what may be a nut. Of course, this would require disassembly, which, understandably, most of us would prefer to avoid.
Since necessity is often the mother of invention, there are always other alternatives to shutting off the “auxiliary” air flow. Later K and L Jet systems employed electronically controlled AA valves. Other types of vacuum controlled air valving exists too. And then there is the base of a single barrel carburetor containing the throttle plate (think lawnmower or motorcycle). It might be adapted too.
A fuel injection system with a manual choke? :shock: . . . . . ? :shock:
http://www.benzworld.org/forums/r-c...auxilliary-air-slide-valve-deconstructed.html
Jaguar version
http://www.jag-lovers.org/xj-s/book/AAVdisassembly.html
Electrically controlled AA Valve from Saab. Must also be a time delay relay.
Mercedes version of electric operated AA valve
http://www.ecstuning.com/Mercedes_B...e-L4_2.3L_111.981/Engine/Emissions/ES1614630/
Mechanical "flap valve?":shock:
