This is my first post here: I am more of a French Press coffee addict, but could not resist buying the very same coffee machine my father used to play with (see the "lever killer" post in this forum). So for now I am trying to get a more subtle coffee out of that beast. Water flows very fast and is too hot.



ISSUES :
In order to have a not so bitter coffee here is the procedure I am following: I just let the thermoblock reach its temperature, then shut it off for ~1 minute , then install the portafilter without coffee and pull two cups of clear hot water (huge burst of steam at the begining), and finally pull my shot.

The pull does not last more than 7~8 seconds. In order to make it a 15seconds pull, the only solution I found was to tamp the coffee like a maniac and grind the coffee almost like greek coffee (one step before actually). The result is unpalatable: lots of crema but way to "acid" for me.



ADDITIONAL CONTEXT :
The porta-filter is a a mix between a 0810 and 0820 : it's got two ears like the 810, but the baskets are similar to the 820. The filter themselves are not like the usual 58mm filter that are advertised : the edge is flat (like on the 820?).









Temperature management is quite primitive: there is a safety round bimetalic switch (in serie) with a sensor inserted in the bloc. The sensor is quite short (4cm) and no idea of its type: not a capilary tube for sure (bimetalic?). This sensor is wraped in a clear material. In order for this sensor to react faster, I've added some heat sink compound, which made the system a bit more reactive, but still very hot.




NEXT STEPS (?):
Another basket for slower flow? Any suitable source? (I would prefer a single/7g basket).

Are there any alternative sensor/thermostat that could fit in this machine? I would rather avoid installing a bulky box in this lovely machine, but any simple solution that would stop these giant burst of steam would make the shots much better for sure.

Thanks for any hint!

You might find suitable thermostats here:

https://www.digikey.com/en/products/fil ... CORJ4vIpAA

Or at least get an idea of what to search for. Hard to tell what the thermostat looks like.

Thanks for the tip as I was heading in the wrong direction: I thought the snap disk was the security fuse, whereas it is actually the other way-round: the snap disk is the temperature thermostat, whereas the "wrapped" element is the security fuse. No doubt this 60 years old snap disk is now totally out of spec and burning my subtle arabica...

This morning was my first "proper" espresso despite the poor temperature management, single cup basket and lack of suitable tamper. It's been quite a challenge, backed by the incredible grumbling of the pump...

At least I know this machine can pull proper shots. With a bit of adjustments and a few repairs, this should be repeatable.

Here a few pictures of my progress.

Although the previous owner had made quite a good job on the exterior, the internals of the thermo block were quite dirty. I just removed as much crude as possible and took note of the specificities of this old group head:

• The group is 800watts unlike what was previously reported, the remaining 200watts are probably for the pump!

• Unlike the 820, there is no separate disk between the shower screen and the thermo block.

• The system lacks the spring valve of the 820.

• The group seal is an odd size : 80mm x 57.5mm x 7mm.

The lack of spring valve is a bit of an annoyance, as at the end of the brew process, a bit of unpressurised water flows in the basket. So you always end-up with water on top of the puck. The more recent valve should be an easy retrofit, but this news design also implies to make it do with the large screw that so many are complaining about, it would also require to use the newer QuickMill shower screen.

The large outside diameter of the seal makes it hard to source, but chances are that a regular 73mm seal would do the trick.

I could easily replace the contact thermostat with a 100°C thermostat from the rancilio (see brown disc). No more burst of steam, narrower temperature deadband, much better coffee.



With a bit more work, this could be a proper machine: it is obviously not in the same league as current models, but it heats up so fast that having a proper coffee does not take more time than a Nespresso.