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      08-18-2023, 07:34 AM   #34
M2guru
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Drives: 2018 M2
Join Date: May 2017
Location: St. Paul MN

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2018 BMW M2  [10.00]
If 28psi is normal idle oil pressure:

Normal start up (after the car sat for a week): It took ~0.5 seconds to build up to ~900 rpms (higher than the subsequent tests). It took ~ 1 second to get to ~28psi. The average engine speed over that 1 second is 913. 913 revs per minute = 15.2 revs per second. If I did my math right, that's ~15.2 revolutions with oil pressure below ~28.

Normal start up log: https://www.bootmod3.net/log?id=64de...0b439c89d6a4d6

Startup after oil drain without spark plugs: It took .5 seconds to go from zero to 235 rpms. It took ~2.5 seconds to build up to ~28 psi. The average engine speed over those 2.5 seconds is 243 rpms. If I did my math right, that's 10 revolutions with oil pressure below ~28.

Without spark plugs log: https://www.bootmod3.net/log?id=64de...729b43b38a162d

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Startup after oil drain with spark plugs: (I reran this test because of residual fuel during the original test). It took .5 seconds to go from zero to 235 rpms. It took ~6 seconds to build up to ~28psi. The average engine speed over those 6 seconds was 230. If I did my math right, that's 23 revolutions with oil pressure below ~28.

During this re-test, I noticed two things: 1) the car sat overnight and that seemed to impact the time needed to build pressure and 2) the second crank didn't seem to add any significant oil pressure. Perhaps it's recommended as insurance...

With plugs: https://www.bootmod3.net/log?id=64df...729b43b38a688e

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Revised video:

Last edited by M2guru; 08-18-2023 at 07:43 AM..
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