Finally I've found the time and courage to take apart the grouphead of my Pro800. It's definitely worth to make a try with a pressure gauge:

Woohoo!

Wow! Super interested in this, as I am seriously considering buying the Pro 800 vs LR in the coming months.

I am watching this thread eagerly.

With a Gabor pressure kit on my Cremina and a Rossa device with a pressure gauge, I know how versatile it makes an espresso machine. The Cremina kit works flawlessly.

To have a pressure gauge on my Quick Mill Achille would be like putting a cherry on the top!

If you can make it work, Gabor....I want one!!!!!

Oh man! Count me in for 2, being as I have a 2 group machine! I just replaced the groups on my vintage Astoria with the same group that's on the pro800 and I would never go back. This would simply be amazing Gabor! I could see myself using this, mainly, to see what pressure my second stage preinfusion is at (when you hold the lever right before it catches and get somewhere between 2-4 bar pressure) and what effect retarding the lever has on my profile. Will be watching this thread with A LOT of interest.

I must also mention that this would be a beautiful addition to the steampunk vibe on our machine.

I love the PP mod on my CT1. It works perfectly, and looks even better!

I assume that this proposed version would work on the Londinium R as well... Am I correct?

Personally I think it would be criminal to have a gauge sticking out of that beautiful group. Don't really see the point as a simple homemade pf pressure rig & 10 minutes of playing around will tell you pretty much all that you will ever need to know. Best thing you could do for that 800 is toss the inner spring in a drawer & put it back together. Of course that's just my opinion.

JohnB. wrote:Personally I think it would be criminal to have a gauge sticking out of that beautiful group.

Oh, noooo! I don't want to go back in jaaaail !

John,
Do not call the sheriff pls! At least not yet. We won't touch that group. As we did not harm the group of the Cremina, Pavoni and Strietman either.

JohnB. wrote:Don't really see the point as a simple homemade pf pressure rig & 10 minutes of playing around will tell you pretty much all that you will ever need to know.

Haven't you ever experimented with the pre infusion pressure? Or holding back the lever during extraction? We'd like to realise a kit which is nicely made, practical, reliable and without compromise during everyday use. A "home made pf pressure rig" can't offer these points.

JohnB. wrote: thing you could do for that 800 is toss the inner spring in a drawer & put it back together. Of course that's just my opinion.

I will give it a try for sure.

naked-portfilter wrote:Haven't you ever experimented with the pre infusion pressure? Or holding back the lever during extraction?

All the time & after a few runs with my pressure rig I know what's going on when I do that so I really don't need to see it every time I pull a shot. I think that your kits are a great mod for a manual lever & as you know I have one on my Cremina. As far as spring levers go I think it will be about as useful as tits on a bull. Nothing more to say so I'll stay out of the rest of this thread.

JohnB. wrote:Nothing more to say so I'll stay out of the rest of this thread.

Don't be that sensitive, pls! I think these kind of discussions can reveal a lot for less experienced users.

JohnB. wrote:All the time & after a few runs with my pressure rig I know what's going on when I do that so I really don't need to see it every time I pull a shot. I think that your kits are a great mod for a manual lever & as you know I have one on my Cremina.

Of course I know. If you sometimes (all the times) hold back the lever of your Bosco, which means you manipulate the pressure, you do sg similar as with a manual lever.
A) After a couple of pulls with a MANUAL LEVER you know exactly what's going on and the piston pressure kits are "about as usefull as tits on a bull".
B) this kit could be just as useful for spring lever as for manual levers.

But I vote for option

C) It's all about personal preferences/taste.

It's optional and any time reversible.

I'd be happy to read more of your comments, John.