Compression K9K-702 1.5DCI

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Compression K9K-702 1.5DCI

Postby Tronic » Wed Sep 27, 2017 1:46 pm

Hi!

Back after a long period of illness and finally, at least with 50% strength, back att work. We have a 2004 Renault Kangoo with a K9K-702 engine and a non start condition. A relative compression test revealed the following mixed compote: 19, 18, 15 and 20 Bar. My question: what are the compression specifications for this particular engine?

Thanks in advance!
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Re: Compression K9K-702 1.5DCI

Postby Technician » Wed Sep 27, 2017 6:16 pm

Hi Tronic,

The technical data I have advises a compression ratio of 18.3.1, this equates to approx 18 bar.
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Re: Compression K9K-702 1.5DCI

Postby Tronic » Wed Sep 27, 2017 10:20 pm

Hi Technician and thanks for reply!

Now I will continue, compression test was just a start. This car have a more or less unknown background, so not much help from there.

Thanks again Technician! :D
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Re: Compression K9K-702 1.5DCI

Postby volrem » Fri Sep 29, 2017 7:49 pm

Technician wrote:Hi Tronic,

The technical data I have advises a compression ratio of 18.3.1, this equates to approx 18 bar.


I disagree. Compression pressure should be higher than compression ratio.

It also depends of additional volume measuring tool has.

With WPS I usually measure measure 22-23 bar (18:1 engine) and with compensation it's 27-29 bar.

post64371.html#p64371
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Re: Compression K9K-702 1.5DCI

Postby Technician » Fri Sep 29, 2017 7:56 pm

volrem wrote:
Technician wrote:Hi Tronic,

The technical data I have advises a compression ratio of 18.3.1, this equates to approx 18 bar.


I disagree. Compression pressure should be higher than compression ratio.

It also depends of additional volume measuring tool has.

With WPS I usually measure measure 22-23 bar (18:1 engine) and with compensation it's 27-29 bar.

post64371.html#p64371


The compression ratio I thought was the minimum acceptable and not the maximum, so yes I agree it should or would be higher when tested dynamically, especially with a warm engine, but as a guide it should be reliable.
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Re: Compression K9K-702 1.5DCI

Postby Technician » Fri Sep 29, 2017 8:21 pm

Technician wrote:
volrem wrote:
Technician wrote:Hi Tronic,

The technical data I have advises a compression ratio of 18.3.1, this equates to approx 18 bar.


I disagree. Compression pressure should be higher than compression ratio.

It also depends of additional volume measuring tool has.

With WPS I usually measure measure 22-23 bar (18:1 engine) and with compensation it's 27-29 bar.

post64371.html#p64371


The compression ratio I thought was the minimum acceptable and not the maximum, so yes I agree it should or would be higher when tested dynamically, especially with a warm engine, but as a guide it should be reliable.


I just located a formula which includes specific heat ratio, therefore;

pTDC = 1 bar x 10.3^1.4 = 26.2

The end result I suspect would very much depends on manufacturer cam and valve timing specifications, volumetric efficiency, and what they have calculated as their specific heat ratio.
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Re: Compression K9K-702 1.5DCI

Postby Mark Dalton » Tue Oct 03, 2017 2:34 pm

I just located a formula which includes specific heat ratio, therefore;

pTDC = 1 bar x 10.3^1.4 = 26.2


That looks like a formula from a wikipedia page "https://en.wikipedia.org/wiki/Compression_ratio" where the 10.3 is the compression ratio, so I think your specific formula should be (1 bar * (18.3^1.4)).
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Re: Compression K9K-702 1.5DCI

Postby Technician » Tue Oct 03, 2017 2:51 pm

I just located a formula which includes specific heat ratio, therefore;

pTDC = 1 bar x 10.3^1.4 = 26.2


That looks like a formula from a wikipedia page "https://en.wikipedia.org/wiki/Compression_ratio" where the 10.3 is the compression ratio, so I think your specific formula should be (1 bar * (18.3^1.4)).


Sorry typo error on my behalf
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