Not sure about the size of the LM gicleur but Dave (Cannonfodder) used a carburetor jet for the A3 as mentioned here with a source mentinoned in the same thread here.

Maybe Paul can also say a word about time for pressure relief from the group after the shot is finished and the solenoid opens.

eastpresso wrote:Not sure about the size of the LM gicleur but Dave (Cannonfodder) used a carburetor jet for the A3 as mentioned here with a source mentinoned in the same thread here.

Indeed, I'm using one of those (actually a stock Elektra Jet, but same threading as those) in my group as I mentioned here. I guess it is M4, based on the info out there.

... which makes me wonder why the major thread diameter on the gicleurs EPNW sent me is 5 mm. I'll look further into this when I get a chance.

Well, back home and I've re-checked. I bought spares of this La Marzocco ruby gicleur for my GS3 and it fits into the boiler pickup tube where it's supposed to be affixed to the machine. I also have Keihin carburetor jets and a standard Elektra group jet. Each of these is confirmed to be M5 by my calipers and any of the product detail pages for the Keihin carb jets.

Yet M4 is the threading you want for mounting in the dispersion screw for sure--the LM group dispersion screw won't likely support being internally tapped to M5. That's probably just as well, as the LM gicleur is way too long to fit in the group above that screw anyway. It is too bad about the Keihin jets, though. So, you'll need to get your own source for M4 gicleurs or make them yourself. As I said previously, Eric's source looks best.

And, as I haven't yet orchestrated a group buy, I will be more than happy to do so. Options would be simply the orifice, a proper tap, the dispersion screw, and a 2 mm hex key wrench as separate parts or a turnkey arrangement where you would receive a new dispersion screw tapped and fitted with the "proper" orifice. My email address is erics@erols.com.

im down!

eric i will be emailing you shortly to get some of these.

thanks!

jon

Here is a simple illustration of the various parts ordered. The dispersion screw insert requires tapping the appropriate M4 thread in the dispersion screw and the other parts fit the "pickup tube" on the GS3 after removal of the installed gicleur. Lots of very interesting combinations possible for the hydraulically inclined GS3 owner by varying the size of the pickup tube orifice and dispersion screw insert .



edit - improved drawing a little and added note about varying orifice sizes.

erics wrote: Lots of very interesting combinations possible for the hydraulically inclined.

Another possibility for the hydraulically inclined is to bring the gicleur out into the light of day, as in the Speedster group:



The gicleur screws into the hex fitting that you see poking out, and is readily accessible for removal and cleaning. Setting up a GS/3 this way would be pretty easy; one would screw in an extension tube where the gicleur normally went.

The disadvantage would be that the new gicleur location would change the pickup location for water going to the puck. Presumably the original pickup location was carefully selected by Bill for best performance. But maybe it would work out just fine.

Eric, can you clarify on the drawings above for the orifice fitting and orifice screen filter--the orifice fitting does have a female M5 on the inlet side so you can "daisy-chain" the orifice fitting (gicleur) and the screen fitting together, correct? Looks like a perfect solution to anybody worried about swarf/verdigris/anything else clogging their gicleur.

That's correct. You can put either one in or both. The filter/screen unit can be screwed into the orfice unit (a typical installation) but not vice-versa.

As regards Andy's suggestion, an adaptor (M5 male to M5 male) is available to do exactly what he describes but the fitment into the passageway might be a little difficult without removing the brew boiler and cutting threads in soft copper tubing is not on my "been there/done that" list as yet.

The screen/filter is rated at 43 microns - that's 0.043 mm and the orifice is 0.610 mm. The filtration rating on the screen is PROBABLY what's termed a nominal rating but still - pretty protective.