Low Oil Pressure

[Ron]

...might be the pic/me, but it looks like one place is smooth, yet blue (heat).

If you don't have the micrometers to actually measure the journals then just get your parts to a machine shop. They should know what to do and how to do it. IMHO the damage is the RESULT of the low oil pressure, not the cause.

+1

Thanks Ron, nothing like this on the flange and counterweights. There some numbers and letters though.
I checked the documentation. Standard size is 70.062mm, which currently it is. Regrind should be 69.762mm, 0,3mm under. So we will take 0,25mm main bearings but they will do it with the crankshaft and the block to the exact measurements of the oversize bearings.
There is big marking "R" still visible on one of the counterweights.
Will replace the bearing with the SKF, too (made in China currently installed).

Only the high spots are 70.062mm.
I would wait until it goes to the machine shop before ordering the bearings, 0,30mm might not clean it up.
No idea what the "R" is for...

[Azar]

...might be the pic/me, but it looks like one place is smooth, yet blue (heat).

+1

Only the high spots are 70.062mm.
I would wait until it goes to the machine shop before ordering the bearings, 0,30mm might not clean it up.
No idea what the "R" is for...

The guy from machine shop told me to get the 0,25mm bearings and he will regrain exactly to this size. Sorry, english is not my native language, did you mean that it might require more than 0,3mm regrind and I may need 0,5mm oversize brarings?

[Ron]

The guy from machine shop told me to get the 0,25mm bearings and he will regrain exactly to this size. Sorry, english is not my native language, did you mean that it might require more than 0,3mm regrind and I may need 0,5mm oversize brarings?

I didn't know that the machinist looked at the crank...he should choose.
(He will grind it as little as he can in steps of 0,25mm.)

[Azar]

If you don't have the micrometers to actually measure the journals then just get your parts to a machine shop. They should know what to do and how to do it. IMHO the damage is the RESULT of the low oil pressure, not the cause.

David, I think you are spot on on this. If you check the photos in my first post, there are metal shavings on the magnet oil drain plug.I made a close up photos of the 4 main bearings and it looks like some hard particles have been dragged in between the main bearings and crankshaft. It is also obvious that the surface of the bearings is harder than the shaft. Was the crankshaft defective from from the manufacturing (not enough hardened)? In any way the filter did a bad job filtering all. Perhaps the previous owner lied about "regular oil changes". I haven't done the first oil change since I got the car (was done at DMCH) but they did not report the shaving. I have made the earlier photos of the oil change last year, half a year later after shipping and registering the car driving less than 100 miles.
Still not clear why the surface below the rod bearings is almost perfect.

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[Bitsyncmaster]

Rod and Main bearings are made with soft surfaces. In the old days you could repair the Babbitt bearings.

[Jakub]

Any new developments?

[Azar]

Any new developments?

Yes, finished motor rebuilt in September, ran 1000km and changed oil, 20w-50. Now in the winter storage since 1st of Nov, waking the baby up in just 2 weeks!

[Jakub]

And how is oil pressure now?
I am particularly interested because I’ve lived oil pressure saga of my own. All in all after numerous intervention I have barely 2 bar at 1000 RPM and 4bar above 2000 RPM.

[Azar]

And how is oil pressure now?
I am particularly interested because I’ve lived oil pressure saga of my own. All in all after numerous intervention I have barely 2 bar at 1000 RPM and 4bar above 2000 RPM.

I need to dig in to the records but the manual gauge connected directly to the motor instead of the dash sensor showing good pressure. The dash sensor is showing low when warm but the light is not coming on. I will monitor in 2022 and report.

2 Bar at 1000 is very good then in warm state? 4 bar above 2000 is perfect. Or am I missing something here?

[Jakub]

I do need also refresh the subject. From memory, and with age memory is not what it used to be, there are different recommendations depending if you dig into Volvo or DeLorean manual.
On the warm day and after prolonged drive the car oil pressure gauge goes really low but the warning light never comes on. And before last work on the engine warning light would flicker sometimes.

On unrelated subject, are you planning to participate in Berlin DeLorean meet in June?