Still, these rotary pumps pump a lot more water than what the groups flow, so most of it goes through the OPV instead. Fitting a bigger pump than necessary just works the OPV more, so as long as the OPV doesn't max out you should be fine.

Yes, of course, you are correct Sebastian. The FOT 1504 delivers about 1/3 of its flow to the PF and simply recirculates the remaining 2/3's via the pump's bypass valve, the total flow being ~ 3.64 litres/minute at 9.0 bar.

Ross - maybe Pasquini needs a phone call and, if you have no luck there, I can assure you that Bezzera typically returns answers pretty quickly, especially when you tell them the whole story and, perhaps, reference this thread.

Do you really need to do all this? - well, might as well, considering the admirable work you have done so far.

Yeah, I'm not saying he shouldn't fix it, I'm just noting a fact, for "in the mean time" use and such.
A good idea would maybe be to get on the phone with the manufacturer, then get on the phone with FOT and see what they say about the whole thing. Since they make the pumps, they can tell you if the pump you've got now is close enough to work or if it would be a good idea to replace it. And you could probably get the one you've got exchanged for the right one since these pumps shouldn't show any wear from installation and testing, if you were careful.

Looking mighty fine. Great job on the restore.

Mark

I took a break from the Laurentis restore to finish the preinfusion pump delay project. I mounted into a small aluminum project box and installed a neon lamp that illuminates when power is applied to the input. It's not as if I can't hear the auto-dosing or auto-fill relay clicking, but I had some spare lamps and it seemed like a good place to put one.

I'm still evaluating whether or not I can discern an improvement in the shots. The main problem being my limited experience. I'm still on the learning curve to pulling some decent shots with or without the timer. But, I'm certainly enjoying the process.