Insights pressure waveform cilider with WPS 500.

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Insights pressure waveform cilider with WPS 500.

Postby tode » Fri Sep 11, 2015 8:32 pm

If possible, I want to bring experiences of sensor use WPS in the study of the cylinder pressure waveform, The purpose of my test is to verify that the pressure waveform corresponds closely to what is happening in the engine.

I chose a very simple engine and mechanically, which to experiment, it is the Fiat 172B2000, the classic 1108 Fire equipping small cars at Fiat, in this case a 600 of the year 2001.
This engine has a single camshaft, in more possess the values in degrees of the openings - closings of the valves, to be given in the waveform the pressure of the cylinder.
The grades are:

Exhaust valve:
Open=-37° (143°)
Closed= +7° (367°)
Inlet valve:
Open= -7° (353°)
closed= +37° (577°)


values are shown in this image:

prima considerzione.jpg


EXHAUST VALVE OPENING

As can be seen from the first screenshot, the first marker in red indicates the 'opening of the exhaust valve, but the point for translation of opening is moved further forward approximately 10°, I think because the piston is still in the ascending phase and the small opening the valve does not immediately generates a lift of the pressure :

zoom open valve ex.jpg
Small delay in the ascent of the pressure


OVERLAP

With the valve overlap exhaust / intake, the consideration is more complicated but the intake valve begins to open 7 ° before TDC to 360 ° and the pressure drops immediately, at this point the piston is practically stopped, starts again immediately after its race and we can see a slight curvature of pressure when the exhaust valve closes:

zoom overlap.jpg
slight curvature of pressure when the exhaust valve closes.


CLOSING INTAKE VALVE

The intake valve closes at + 37 ° (577 °), while the piston is in the ascent phase, in fact the pressure is starting to rise, but we can say that where there 's the slight oscillation of the pressure corresponds to the closing of the valve:

zoom closed inlet valve.jpg


CONCLUSIONS

Finally, the response pressure in the opening/closing valve occurs with a slight delay compared to the real point, but we can say that it is a fairly insignificant, for me, depends on what we have to do tests and assessments that are used for diagnosis.
These are considerations of a simple motor, without peculiarities and clearly idling.

If I'm wrong some consideration, correct me and any advice is accepted to grow and learn.
Last edited by tode on Wed Sep 16, 2015 9:10 pm, edited 1 time in total.
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Re: Insights pressure waveform cilider

Postby LEYLAND MILL MOTORS » Sat Sep 12, 2015 12:56 pm

How do you add the text boxes, arrows and additional information to the screen shots?

Is it a feature within Pico's software or additional software?

thanks

Steven
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Re: Insights pressure waveform cilider

Postby Robski » Sat Sep 12, 2015 2:03 pm

Is it a feature within Pico's software ?

No.
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Re: Insights pressure waveform cilider

Postby LEYLAND MILL MOTORS » Sat Sep 12, 2015 6:30 pm

Dose anyone have any pointers as to what the additional software is?
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Re: Insights pressure waveform cilider

Postby Robski » Sat Sep 12, 2015 6:47 pm

LEYLAND MILL MOTORS wrote:Dose anyone have any pointers as to what the additional software is?

Snagit
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Re: Insights pressure waveform cilider

Postby tode » Sat Sep 12, 2015 7:38 pm

I used a program to capture images called Fastone capture.
but you can used the Paint a windows program, how to use it?
You choose the image from the screen Pico, Or any screen, even the one you are watching now, press the button on the keyboard "Print";
You open the Paint program, which you should find in Windows accessories and opened it, now you press the keys "Ctrl" and " V" at the same time or menu of paint you choose the " paste " command;
The stored image when you have pressed the print button is displayed;
Now you can use all options of the program to insert arrows designs geometric shapes or cartoons .....
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Re: Insights pressure waveform cilider

Postby LEYLAND MILL MOTORS » Sat Sep 12, 2015 7:45 pm

Thank you for that Tode :D
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Re: Insights pressure waveform cilider

Postby Robski » Sat Sep 12, 2015 8:05 pm

but you can used the Paint a windows program

OS dependant.

Thank you for that Tode

No probs from me too, seems my reply was invisible to you....... easily remedied :roll:
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Re: Insights pressure waveform cilider

Postby LEYLAND MILL MOTORS » Sun Sep 13, 2015 8:13 am

Sorry Robski, I didn't notice your reply, I am looking at that now.

Thanks Robski
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Re: Insights pressure waveform cilider

Postby Fat Freddy » Sun Sep 13, 2015 9:27 am

There is also Annowave - not free https://www.annowave.com/ . Or the one I use Paint.net. Free and has a great merge layers feature. That can be used to tie various events to the crank clock. https://www.getpaint.net/index.html

HTH
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