Greetings,
This is my first post, I will do my best to not sound too noobish.

I have had my silvia for 6 months and I am in the process of dialing it in for more serious usage. Alot of reading has been done on my part, and I feel like I reached a point where I needed to ask a few questions.
In order to get the most of of this machine, I am trying to see where the settings are now for pressure and temperature.

So, I made a portafilter gauge, I got parts from McMaster Carr, and the 200 psi glycerin gauge from there as well. With teflon tape and the removal of the basket, I was able to make a good seal at all connections. I am using a needle valve to approximate espresso flow, and I made a small movie of my efforts this evening. I am recording 12 bar at the gauge, with the valve somewhat open, if my technique is correct. I tightened up a few leaks afterwards and retested several times, all with the rapid climb to the 12 bar level. In the movie, it can be seen that when I adjust the valve to open it slightly more, the gauge pressure dips momentarily, then raises again to 12 bar. Here is the movie...
http://gallery.me.com/portergieske#100521
That's a little high, right? I was under the impression that the opv was set to open at 10.5-11 bar.
I am happy to report that I found and ordered the newer version OPV from a reputable shop online, this one is the more easily adjustable one from the V3. This should end my troubles in this area.

Now for temperature-
I bought a nice digital thermometer probe, one with +-.5 a degree in Fahrenheit. Its a food probe model, not too fancy or pricey, but it is exact, I calibrated it too.
Here's what I found out from testing it tonight:
I used a double walled stainless steel mug, one that doesn't quickly lose heat. I began the test after a moderate warm up time of about 30 minutes. I wanted to start low to see the temps rise. I put a portafilter in with no basket and no diverter below, it was after I removed the gauge piping. I flowed water through the grouphead and saw temps in the low 180's. I kept the water in the cup and the probe in the water and waited for the boiler to cycle until the light went off. My process from here on out was to dump the water, replace the probe and run water into the mug. Round 2 went into high 180's. Cycle 3 saw high temps of 195, at about 6-7 seconds into the pumping. Everything seemed to be getting hotter and holding it better. Dump and rerun cycle 4 and it went to 199, held there, then slowly dropped off to 197 as the pump light went on near the end. Now I can only run the pump for about 6-7 ounces, due to the size of the mug.
I let the boiler go a full round and when the light turned off, I dumped the hot water and ran the pump. This time, I definitely saw 202.5 for a few seconds, right at the start of the flow of water. It began at 199, shot up to 202.5, along with sputtered out steam as well, then dropped to 201, 200 and held for the filling of the cup. I consider this to be just a guesstimation of the real temps inside the portafilter, my test was just to reconfirm that the old lady was still able to kick out nice numbers. I had to quit at this point (kids), but it tells me that 1) I need to let it really warm up for the higher temps and 2) I can now look into figuring out how long to wait to surf for the right temperatures. My plan there is to count seconds away after the boiler light goes out, and not try to hit the temp with the boiler on the rise.

I have had fair to good results despite my high pressure and low temps. I use a naked portafilter to improve my tamping and dosing technique. I use a quality digital scale for dosage, and I in full understanding of grind optimization for flow volume at specified duration. That all makes sense to me. The designer in me is dying to make a 30 pound tamper from a precision spring and some tubing, all I have to do is attach the coffee tamper base and mark the calibrated level. Much like the spring loaded hole punches, without the click and kickback.

Comments are welcomed on where i stand with all of this, I have already swapped out the steam arm and valve for the new version, that helped the foaming some. I feel like I am making some good cappas, milk hides alot. I am very much enjoying the journey, and I feel that there is a nice long way to go before I make serious espresso.

thanks

sprint jinx wrote:That's a little high, right?

Yes, 12 bar is too high. Adjust the over-pressure valve.

sprint jinx wrote:I bought a nice digital thermometer probe... <snip snip snip> ...My plan there is to count seconds away after the boiler light goes out, and not try to hit the temp with the boiler on the rise.

There are countless pages of instruction on temperature surfing the Rancilio Silvia. Mark's video shows you a shorthand method that by all account works quite well:

sprint jinx wrote:Comments are welcomed on where i stand with all of this...

Er, nowhere in your post did I find an answer to the most important question: How does the espresso taste?

Porter -

If you have not yet installed the newer adjustable OPV, this could save you a few $.



Your V2 Silvia OPV may be fitted with those small stainless steel spring shims. Removing those shims will lower your OPV's setting.

Silvia needs about 45 minutes to fully & uniformly warmup - installing a digital timer makes this an effortless task. Silvia also benefits greatly from the installation of a PID - this takes temperature surfing "out of the picture."

The main purpose of grounds distribution & tamping is to create a near uniform density of coffee for the water to pass through while also moving the coffee bed away from the dispersion screen. Consistency would be more important than any actual force value - check yourself on a bathroom scale.

Where are you located in Baltimore and what coffee are you using nowadays?

Thanks for the replies, I appreciate the info.

Eric - I am in northern baltimore in 21093, and not southern towards where you are from in Silver Spring. I have been sampling the local roasters fare like the baltimore coffee company, 'spro, and most recently, Zeke's. Their mobtown beans produced great tasting results, with early blonding occurring at 20 seconds in. I'd like to see the pressure and volume slow down a bit to combat it. Its a little out of the way to obtain it, but I think that I will be going there regularly.

I have already pulled the trigger on buying the more adjustable OPV, despite being aware of being able to adjust the pressure on the older OPV with fiber or copper washers. With the age of this machine and the hassle of trial and error on the method, I figured why not just go with the new part. I like being able to adjust the nut and not having to add the right distance washer. The odd thing is that I rang up the shop and asked them which way was the better choice, of course they were going to say - buy the new one.
If I have any hassle with the new opv, it is good to know that I can stiff futz with the older one.

I am certainly leaning towards a pid, in time. And, the timer makes alot of sense too, I'll look into it. If there is a tried and true unit for cheap, I'd like to hear about it.
Edit - they are all over the place and cheap, I'm set, pun intended.

thanks
p

Silvia temp surfing/warmup:

I've read numerous references to 'cycling' the boiler heat/t-stats to get the Silvia up to an acceptable operating temperature.

What I have NOT read is using the steam switch to get the machine to that acceptable temperature faster. I DO use the steam switch in that fashion and check 'pre-pull' water temps using a non-contact 'laser thermometer'. I don't expect +/- .005° from that device, but when water out of the PF is running around 190°, I figure that I'm close enough, and I get there without multiple cycles.

So...why NOT use the steam switch to decrease warm-up times?

canyncarvr wrote:So...why NOT use the steam switch to decrease warm-up times?

I do this too, as a preliminary warmup for the parts. But, because the temperature would be rapidly moving up to the steam setting value with the switch on, to where it is too high to make espresso, hitting the target would be difficult. Running water through the grouphead to lower it from there just produces steam and water until just water comes out. That water temp is generally lower than what is needed for espresso. It is effective for warming up all of the system and group, but I have found it to be too variable in temps for good control.