123 Distributor failures from oil?

[Dick Steinkamp]

I have the original 3.0 in my E3. Virtually no oil in the tube from the valve cover to the air cleaner or in the air cleaner itself...even after the 2,000+ mile high speed trek to Legends and back. I have good compression on all 6 and good performance. No oil in or under the stock distributor. No drips under the car (yet). No record of the motor ever being rebuilt (although it is a possibility)

I think the only way that crankcase pressure can build is through blowby past the rings. Which (to me) means rings worn, rings not yet "seated", and/or (maybe?) higher then stock compression ratio.

I was surprised when I first started working on the car that there is no Positive Crankcase Ventilation system...only the hose from the valve cover to the air cleaner. A typical PCV system looks like this...

A good source of vacuum from the crankcase to the intake manifold and a filtered source of make up air. Would a true PCV system solve this problem?

 

[Stevehose]

Virtually no oil in the tube from the valve cover

My tube is bone dry too, so oily residue not necessary for this to happen. I agree it's the blowby (agree with your idea regarding old/unseated rings, higher compression exascerbating this) which BMW and other manufacturers have accounted for (like the vent to air cleaner tube you have). I suppose if the stock setup is not used and/or the engine has more blowby than spec'd, we have a problem. In the old days before the crankcase draft tube, followed by the PVC system, engines routinely blew oil past the seals as part of the design, and was considered normal.

 

[adawil2002]

I have 123s on Athena & sent it back to add the new milled spindle last year.

Veronika the 1969 1600 Cabriolet has milled spindle & is so far oil free.

I've been running a 123 on Vern since 2016 & have sent it back every 16K miles. This year I felt some pulsing & noticed oily dirt on the 123 housing, reclined the distributor cap, rotor & circuit board every other fuel stop. Ordered a new 123 with the milled spindle.

 

[Stevehose]

Ok checked a few days ago - was fine. Today, oil. Crankcase vent tube still dry, oil consumption close to zero in 800 miles. No oil leaks anywhere, compression is 198-205 all cylinders. I put an anemometer to the valve cover vent hole and get very little air movement at 3k rpm, none at idle. Engine runs beautifully otherwise. I'll be traveling for the next month+ so this will give me time to formulate Plan B which may involve some upper timing cover mods.