Izzo Alex Leva - preinfusion workings

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LuckyMark

#1: Post by LuckyMark »

I have read the great review of the Profitec Pro 800 Array/reviews/profitec-pro-800-review-t44660.html. This review gives a great description of how the dipper mechanism in the Pro 800 works, with prewetting then pre infusion. I have a Alex Leva and realise I am not totally sure how it works. I understand that when you lower the lever to the halfway point, where it activates the little rod at the rear, the water flows freely and at some pressure. I assume boiler pressure as the inlet line would be shut? Is the bottom of the stroke different? When does the cylinder close from the boiler? Just trying to get a handle on how everything works (rather than just using it). Thanks Mark

Parkeralto

#2: Post by Parkeralto »

I just fired up my new Alex Leva today so I am not an authority by any means but my understanding is that line pressure (or pump fill) has little or nothing to do with pre infusion on these machines. At the factory setting of 255f gives you 1.3 bar of boiler pressure for pre infusion. Changing the temp setting changes the boiler pressure. I lowered mine to 250f for about 1.1 bar. which is working well for a pre infusion of around 8 sec.
From the factory mine opened the water valve with the lever about 1/3 of the way down. I adjusted that valve opening to the neutral point of spring pressure, about horizontal lever position to make it easier to control pre infusion water flow. I did notice that when the lever is all the way down (piston up) the water flow seems to be restricted a bit and I have not figured how that happens.
And the coffee.... even the first shot was good, all the next were excellent and compared to my E61 machine, noticeably softer. Lever machines are different.

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belegnole

#3: Post by belegnole »

I've found that looking at parts diagrams such as this one can be enlightening when seeking to discover how something works.

Also, the Pompei group service video shows the La San Marco group being assembled. You'll want to download the video as it's the only way to watch the whole thing. Anyway watching it has helped me understand this group.

To answer your questions. When the lever handle is pulled down enough the small adjustable lever pushes down on a spring loaded valve. When it is pushed, it opens allowing water from the boiler (at boiler pressure) to enter the group below the piston and seal. The valve remains open until until the lever handle is raised.

Of course the next question becomes "well what does that adjustment do? And how am I suppose to set it?". Well so far I've left mine as it was set at the factory. Others have said that they played with theirs and and it didn't seem to make any real difference. Personally I think that while you can adjust it so that the valve opens up more, or less. It may not be noticeable in the cup. At some point I'm going to play with mine as well. The first thing I'll probably be doing is setting it up so that the valve barely opens. Then I'll probably slowly adjust it to open up more and measure the volume of water coming out. But all that's for another day. As I've had the machine for less than a year and I haven't felt a great need to poke at that little mystery, yet.
LMWDP #641

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TomC
Team HB

#4: Post by TomC »

I've fiddled with mine, never seeing any appreciable difference, which left me scratching my head.

Dr Espresso out of London reassured me a few months ago that there's no "adjustment" available, that it's just a simple infusion valve, on/off. But it doesn't seem quite like a Gaggia group, where you can essentially shut off water flow to one group and service it, while the other groups keep on working.

I really wish LSM/Izzo engaged more with their customers to explain things like this. It's not like the design has changed in the past 50 + years.

drH
Supporter ♡

#5: Post by drH » replying to TomC »

If Izzo engaged more with customers they would also sell a heck of a lot more in the US. I think lack of awareness and support are drawbacks when people are looking for lever machines. Profitec becomes an obvious choice.

LuckyMark (original poster)

#6: Post by LuckyMark (original poster) »

Thank you everyone. Will download the video and won't chase any (sounds like non existing) adjustments till I understand the basics. Thanks

puffinjk

#7: Post by puffinjk »

If you want to adjust your group head so you can get a nice gentle shower and preinfusion remove the actuator and remove the locknut and install it on the top of the thru threads, then you have all the adjustment you want, You will have to remove one of the acorn nuts and a seegar clip to remove the thru pin to do all this, Be careful to put a towel down so the seegar clip doesn't run away. Jim :D

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puffinjk

#8: Post by puffinjk »

A few other things I forgot to mention about adjusting the flow, once you get it where you want it you can tame it more by adjusting the pressure stat down I have mine set to 1.1. After all that your grinder may need some adjusting because your not blasting the hell out of that coffee puck anymore. Jim :D

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espressotime

#9: Post by espressotime »

I don't think that screw ever was meant to do anything. It 's just there so you can assemble the group without putting tension on the valve.
Grind,rake ,tamp and enjoy a great espresso.( by F. G.)

puffinjk

#10: Post by puffinjk »

Well that screw does turn the water on and off in the group, And the locknut defeats any adjustment,I have been running mine for quite some time this way with very positive results, It may be one of those things where it might not be for everyone, But I like the preinfusion, shower flow, cleanliness, coffee profile.