On the problem of the timing chain

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On the problem of the timing chain

Postby pantiancai » Sun Apr 29, 2018 6:04 pm

Hello everyone
Ask a question about timing chain elongation
An 11-year VW CC equipped with EA888's engine, we did a normal maintenance for him and replaced the defective timing chain. Before that, I measured its CKP CMP with pico 4225 (Idle speed and removed the camshaft position adjustment. ()), CMP lags behind the CKP's 14th tooth by about 1.7 degrees. I replaced the timing chain lag and I measured again. At this time, the CMP is 1.4 degrees ahead of CKP. Can I think that the old timing chain is elongated? At 3.1 degrees, the length of the timing chain can be calculated on the premise of knowing the length of the timing chain. I do not know if my judgment is correct?
Does CMP advance or lag relative to CKP when the timing chain is stretched?
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链条拉长.jpg
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Re: On the problem of the timing chain

Postby pantiancai » Mon Apr 30, 2018 6:13 am

Before the replacement
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Re: On the problem of the timing chain

Postby pantiancai » Mon Apr 30, 2018 6:17 am

After replacement
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更换后.png
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Re: On the problem of the timing chain

Postby kona » Mon Apr 30, 2018 7:29 pm

pantiancai wrote:Hello everyone
Ask a question about timing chain elongation
....... and replaced the defective timing chain. ........


Only one chain? ..... or the whole set? :?:
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Re: On the problem of the timing chain

Postby Liteace » Mon Apr 30, 2018 10:56 pm

pantiancai wrote:Does CMP advance or lag relative to CKP when the timing chain is stretched?


If your looking at the front of the engine and the engine is running clockwise, the tensioner is on the slack side of the chain (its not slack as the tensioner is there) and not the pull side, as the as the chain stretches the tensioner will move out and will move the cam/s anticlockwise and the crank clockwise unless the chain is really baggy and the tensioner is at its stop
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Re: On the problem of the timing chain

Postby pantiancai » Tue May 01, 2018 12:40 pm

Liteace wrote:
pantiancai wrote:<trans data-src="Does CMP advance or lag relative to CKP when the timing chain is stretched?
" data-dst="是否提前或滞后相对于CMP CKP时正时链条被拉长?报价">是否提前或滞后相对于CMP CKP时正时链条被拉长?报价</trans>

<trans data-src="If your looking at the front of the engine and the engine is running clockwise, the tensioner is on the slack side of the chain (its not slack as the tensioner is there) and not the pull side, as the as the chain stretches the tensioner will move out and will move the cam/s anticlockwise and the crank clockwise unless the chain is really baggy and the tensioner is at its stop" data-dst="如果你看着前面的发动机和发动机运转顺时针,张紧器对链条的松边(不松张紧器有)和不拉边,作为链延伸器将搬出去,将凸轮/逆时针转动,曲柄除非真的是顺时针链宽松和张紧器处于停止">如果你看着前面的发动机和发动机运转顺时针,张紧器对链条的松边(不松张紧器有)和不拉边,作为链延伸器将搬出去,将凸轮/逆时针转动,曲柄除非真的是顺时针链宽松和张紧器处于停止</trans>
The camshaft rotates counterclockwise, the crankshaft rotates clockwise, so there is no reference, because both positions will change and cannot be calculated. How long the chain is stretched can only be roughly seen when the chain is elongated and the phase changes.
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Re: On the problem of the timing chain

Postby pantiancai » Tue May 01, 2018 12:41 pm

kona wrote:
pantiancai wrote:Hello everyone
Ask a question about timing chain elongation
....... and replaced the defective timing chain. ........


Only one chain? ..... or the whole set? :?:

A timing chain, not a set
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Re: On the problem of the timing chain

Postby kona » Tue May 01, 2018 7:36 pm

pantiancai wrote:
...The camshaft rotates counterclockwise, the crankshaft rotates clockwise, .......

:shock:

Please indicate engine ID code (4 letters).
pantiancai wrote:
A timing chain, not a set


Well, then everything is believable.
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Re: On the problem of the timing chain

Postby pantiancai » Wed May 02, 2018 12:29 pm

kona wrote:
pantiancai wrote:
...The camshaft rotates counterclockwise, the crankshaft rotates clockwise, .......

:shock:

Please indicate engine ID code (4 letters).
pantiancai wrote:
A timing chain, not a set


Well, then everything is believable.

CGMA
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Re: On the problem of the timing chain

Postby Technician » Sat May 05, 2018 3:58 pm

CGMA?

I read something about management and training regarding the above, but I'm sure it might mean something different!

Then there is a difference of the OTTO cycle that I'm not aware of, that being crank rotation being in opposite direction to cam rotation!

That's got to be a misunderstanding surely!
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