Cam variations bank 1 – within LN spec but slightly drops on back to idle from 3K rpm

[lemikson]

I would appreciate comments on findings with Duramteric Pro Cam Deviation tests on a 06 997 C2S, 45K miles with superb maintenance history over the whole lifetime. Regularly tracked but never abused with twice a year M1 oil changes and an OCD for proper engine warm up / use and servicing.

Engine running 20 minutes and engine oil got to 200F before tests.

Both Bank 1 and Bank 2 deviations are rock solid (zero change) from idle rpm up to 3K rpm.

Holding 3K rpm for some time (30-ish seconds), followed by full & sudden throttle off with engine speed quickly coming down to idle rpm on its own.

Bank 2 variations values holds steady every time at the same value as it was on the rpm up side.

Bank 1 variations decreases in a very small increment every second test and only when engine is back to stable idle rpms. Variations don’t change while engine rpms are decreasing from 3,000 rpm down to idle – rock stable. Smooth engine speed transition into idle every time.

Here are the numbers:

TEST 1: IDLE 3K RPM IDLE

BANK 1 -3.8125 -3.8125 -3.7500

BANK 2 1.0938 1.0938 1.0938


TEST 2: IDLE 3K RPM IDLE

BANK 1 -3.7500 -3.7500 -3.7500

BANK 2 1.0938 1.0938 1.0938

TEST 3: IDLE 3K RPM IDLE

BANK 1 -3.6875 -3.6875 -3.6719

BANK 2 1.0938 1.0938 1.0938


TEST 4: IDLE 3K RPM IDLE

BANK 1 -3.6719 - -3.6719 -3.6719

BANK 2 1.0938 1.0938 1.0938

More than 20 minutes passed between Test 2 and Test 3 and about a minute between the 1&2 and 3&4. Can upload videos / attach link if anyone would like to see.

Is this level of change (6/100th of a degree or even less) indication of anything known?

[lemikson]

Here are the screen shoots. Again, any comment is very much appreciated.
- first: at 3,000 rpm (steady all the time from idle to 3K rpm and kept for 30-ish seconds):
Cam deviations bank 1 value = -3.8125



- second: at idle speed when rpms saddled down (from throttle off all the way down to idle revs deviations value don't change - they slightly change only when engine gets at steady stable idle rpms)
Cam deviations bank 1 value = -3.7500



- third: change in deviations value is so small that you barely can see that the graph line is shifting ever slightly
Arrows pointing moment when Cam deviations bank 1 value dropped down to -3.7813 before finally saddling at -3.7500