123 Distributor failures from oil?

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...

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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?
 
Dick Steinkamp said:
Virtually no oil in the tube from the valve cover
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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.
 
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.
 
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.
 
Ok I’m firing my last 2 bullets before crying Uncle. First, I noticed that oil gets up between the gear and shaft on the 123 (it’s not on very tight and is pinned in place). This could possibly be the entry point for the oil, the other entry point is higher up at the bushing, away from any potential oil pooling/pressure so I have removed the gear, added some JB Weld to the shaft as a sealant, and sealed the bottom of the gear so there is NO freaking way oil is getting past this gear.

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Next I drilled an oil relief hole where the oil might pool at the base of the dist shaft. There will still be plenty of oil splashing around for lubrication but hopefully won’t be there for pressure or whatever to push it up or however it’s getting into the 123.

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Meanwhile, I have no evidence of any blow-by oil in the valve cover vent tube, and I checked that this is not blocked internally so I won’t know which if either is the solution if my leaking is solved but I don’t care at this point. It will be another 1000 miles before I can report success or my pending harakiri.
 
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You don't give up.... I did and the stock dizzy has been fine ever since.
Good ideas, I would never be brave enough to drill a hole.
The JB seal is a great idea!

Hope this works.
You'll be a hero if it does.
Still have my 123 in a box but the oil may have ruined it.
 
300 miles and it's BAAAAAACK.....

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So much for the previous theories, on to the next one. Having anticipated this, I went ahead and came up with another hare-brained scheme and ordered the parts for the "123 double seal mod." After removing the "upgraded" Bosch style reverse-grooved oil shaft, I noticed it had imprinted itself into the bushing:

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This makes me uneasy so I went back with the stock non-grooved shaft (which wasn't leaking before I went ahead and installed the grooved one as "preventative" maintenance).

I ordered two 4mm Viton shaft seals (the 123 comes with one 5mm one) so that I can double up on the sealing potential. In order for this to work I had to cut down the standard 16mm bronze bushing by 3mm in order for them all to fit properly inside the 123 housing. So thanks to @jjs2800cs and his lathing skills, we have a new system:

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The upper seal got filled with grease, the lower one will be installed as is:

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All went back together smoothly (at this point, I can do this blindfolded in a foxhole under enemy fire) and it's now in the car ready for another go. I also cut my valve cover breather hose in half and attached a larger diameter hose to the lower half out of sight down by the block, this has lessened the airflow resistance somewhat to hopefully help with even more pressure venting.

See you in a few hundred miles!
 
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Steve, hop on the Amtrak Auto Train to D.C. & come up for The Vintage at Saratoga in October. Drive cross lots ma be ablaze of peak leaf season through NY, VT, NH, visit VSR & Stan, come up to me in ME for a visit...No AC needed. Auto Train home...then check 123 for oil along the way.
www.saratogaautomuseum.org

Vintage at Saratoga: BMW — Saratoga Automobile Museum

Join us at the Museum for the 2024 BMW: Vintage at Saratoga October 12, 2024. This show is open to All BMWs 1999 and earlier including all E36s. more information at www.vintageatsaratoga.com
www.saratogaautomuseum.org www.saratogaautomuseum.org
 
adawil2002 said:
Steve, hop on the Amtrak Auto Train to D.C. & come up for The Vintage at Saratoga in October. Drive cross lots ma be ablaze of peak leaf season through NY, VT, NH, visit VSR & Stan, come up to me in ME for a visit...No AC needed. Auto Train home...then check 123 for oil along the way.
www.saratogaautomuseum.org

Vintage at Saratoga: BMW — Saratoga Automobile Museum

Join us at the Museum for the 2024 BMW: Vintage at Saratoga October 12, 2024. This show is open to All BMWs 1999 and earlier including all E36s. more information at www.vintageatsaratoga.com
www.saratogaautomuseum.org www.saratogaautomuseum.org
Click to expand...
someday!
 
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