Dear Sam,
Your modesty is a shining light...
Thanks for all the interesting points you bring up, food for thought.
I will try line pressure reduction and flow rate reduction. Totally agree that pressure may not be < 1.2 bar, else filling of the boiler will become problematic.
Personnaly I wouldn't mind a pre-infusion pressure of 1.5 bar. I have worked for a couple of years with a vintage Conti prestina (dipper design) which has pre-infusion taking place at boiler pressure (0.9 bar). Never any problems or whatsoever...
I am aware that Londinium is working with elevated pre-infusion (3 bar). Have you seen the design of the cylinder? It is doublewalled and has four inlet ports, hence optimized dispersion.
There is some more experimenting to do. Keep you updated.
Regards, TY

turboyeast wrote:Personnaly I wouldn't mind a pre-infusion pressure of 1.5 bar. I have worked for a couple of years with a vintage Conti prestina (dipper design) which has pre-infusion taking place at boiler pressure (0.9 bar). Never any problems or whatsoever...
I am aware that Londinium is working with elevated pre-infusion (3 bar). Have you seen the design of the cylinder? It is doublewalled and has four inlet ports, hence optimized dispersion.

Agree with you there. 3 bar preinfusion working well on one type of machine doesn't automatically mean all other levers have gotten it wrong. Thousands of levers out there had used that config for decades with great results.

Yes, [anonymized] has a beautiful set of pictures on the water dispersion which I'm sure you've seen. I am envious of the improved functionality of their group head but as consolation, I think the Aurora group head is more gorgeous. I guess we can't have it all

Let us know how it goes!

Hi Sam,
Will keep you informed about progress. Yes, I have seen the pics. [anonymized] is actively participating in my post on Koffiepraat.
http://www.koffiepraat.nl/forum/viewtop ... &start=160

I agree that the Aurora group has feminine characteristics which makes it particularly attractive....
Cheers, TY

Dear all,
Yesterday I installed a pressure reducer, a needle valve and a manometer to do some experimenting with respectively pressure and flow. I noticed that playing with pressure, influences jetting the most and flow restriction doesn't do so much. As Sam already mentioned, there is a thin line since boiler (auto)fill is seriously (negatively) influenced by a low pressure (1-1.5 bar). The optimum between avoiding jets and getting satisfactory boiler (auto)fill is at approximately 2 bar. Having that said, I will also install the extra dispersion screen as suggested by fellow Aurora owner Sam.
The result of some experimenting (in the cup) is FANTASTIC!
Cheers, TY

TY,

That is quick, thanks for reporting back! Welcome to the Aurora club and enjoy the fine God Shots to follow.