WPS500S question

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grunf1976
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WPS500S question

Post by grunf1976 » Sat Nov 12, 2016 10:20 pm

Hello,
I just got WPS sensor and would like to know if it can be used in diesel running compression testing, as most cars that Im working on are VW diesels?
Thnx

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STC
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Re: WPS500S question

Post by STC » Sun Nov 13, 2016 12:32 pm

Grunf

The official line will be that it is safe and accurate to use up to 500psi (34.47 bar). Being a quality product, it will probably be ok if you were to exceed that by 10 - 15% occasionally and for very short periods however that would be at your own risk and unadvisable.

Use a Dial Gauge to get an idea of what these engines are peaking at to make the decision before you put safety and the WPS at any unnecessary risk. Just be sure fuel delivery to the cylinder is paralysed whilst testing.
Last edited by STC on Sun Nov 13, 2016 5:38 pm, edited 1 time in total.

volrem
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Re: WPS500S question

Post by volrem » Sun Nov 13, 2016 1:26 pm

It's ok if you don't exceed maximum pressure range as STC stated. Check with mechanical gauge first.
And there is lot of heat so I would say it's safe for a short period. I have used max 10 seconds at time.

grunf1976
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Re: WPS500S question

Post by grunf1976 » Sun Nov 13, 2016 4:04 pm

Thnx for your info. I never used transducers before, just was curious if it is possible and safe to use.

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Autonerdz
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Re: WPS500S question

Post by Autonerdz » Sun Nov 13, 2016 7:00 pm

The pressure is not the issue. Heat is.

You can do diesel running compression testing as long as you do it for a short time. The higher diesel pressures generate a lot more heat. That is what will damage the WPS battery and cause it to fail. So, set up, make your capture and shut it down. Don't leave it on there for any length of time.

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Re: WPS500S question

Post by victor2k » Sun Jan 08, 2017 12:12 pm

Hello,
I found some info about the peak pressure in cylinder during burning process in a older training of diesel engine.
I can't upload the file so I will attach a link for download(the pressure can reach 5-6 MPa at 10*ATDC,not specified in what conditions:idle ,partial load or full load).From my measurements I noticed a increase of pressure at idle/compression by 25%...
Here is the link:
https://mega.nz/#!4Ahy2IzK!hM39gG-ICN9D ... SRPdfq540Q
Also for the peak of pressure will need a new marker for 10*ATDC if the fuel/air is ignited :roll:
Regards
Last edited by victor2k on Sun Jan 08, 2017 4:27 pm, edited 1 time in total.

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Re: WPS500S question

Post by STC » Sun Jan 08, 2017 4:11 pm

the pressure can reach 50-60 MPa
That is some 5 - 600 bar whereas the WPS has a limit of 35 Bar.
Also for the peak of pressure will need a new marker for 10*ATDC if the fuel/air is ignited
On a modern Common Rail we may see many pressure peaks before and after TDC.

We now have pressure sensing Glow Plugs, Perhaps a tool maker could take that technology and produce a universal set to fit many engines (those that are not fitted with them from VM) that would enable in cylinder testing with it running and firing in the cylinder. Would not be easy to buy an off the shelf transducer that would sustain that heat.

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Re: WPS500S question

Post by victor2k » Sun Jan 08, 2017 4:24 pm

STC wrote:
the pressure can reach 50-60 MPa
That is some 5 - 600 bar whereas the WPS has a limit of 35 Bar.
Also for the peak of pressure will need a new marker for 10*ATDC if the fuel/air is ignited
On a modern Common Rail we may see many pressure peaks before and after TDC.

We now have pressure sensing Glow Plugs, Perhaps a tool maker could take that technology and produce a universal set to fit many engines (those that are not fitted with them from VM). That would enable in cylinder testing with it running and firing in the cylinder. Would not be easy to buy an off the shelf transducer that would sustain the heat

Not sure that I have ever seen the need to do that for fault diagnosis purposes.
Sorry,
It was 5-6 MPa(50-60 kgf/cm2),I edited my previous post.
I think we must keep a low speed of engine to protect our pressure sensors if the engine start somehow(wrong sensor disconnected,oil in intake manifold,...)
Thank you.

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