123 Distributor failures from oil?

Gary, this is a great investigation you are pursuing. I'm guessing milling the oil scroll on the shaft may not be a simple or inexpensive mod. Curious to see what your brother says.

By the way, this is a common technique to keep oil out in lieu of a seal. Seen here in the Citroen 2CV engine on the camshaft where it simply sits on the case without any bushing or seal and it effectively keeps oil from escaping.

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Here's the shaft of the 123 after my brother did the heli coil work on it.
There are actually 2 lines on the BMW shaft. One groove starts and goes around a couple times then stops. A little space and groove starts again.
It will be a while till I can test this.
Ed at 123 was very interested in what we did.
 

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Thank you Gary. Ray Koke in Savannah has suggested 123 also do the machining as you've done. May your efforts be more successful.
 
I have some news about 123 dist shafts.

If you have had this problem 123 in Ohio has had a few shafts modified.

No mention of how any remedy of existing units with the oil problem would be handled.

I have done my dist shaft but still don't have my motor running again so I can't give a report as to how effective this "fix" will be.
Here are photos of shaft done by 123 in Ohio. Ed is the US rep for 123.
If you have any questions please let me know and I will try to answer to the best of my ability.

BTW if you have had problems with oil contaminating the electronics of your dist please let me know.
Trying to find out some estimate of how widespread this is?
Thanks,
Gary
 

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I'm only the messenger.
Since I took the initiative to research this problem he has been in contact with me.
In fact I sent him a Bosch dist shaft to give to his machinist to see how it was done after my brother did one for me on his lathe. Photos in thread above.

Also there is some skill involved in swapping this out. A new brass bushing should be installed and a seal inside the dist housing. Ed or I have those part numbers but removing the brass bushing is a little tricky. The seal is a special order item not found on popular sites like McMaster. The seal is basically a small version of a crankshaft or cam seal. Even has the little spring.

I think he is reserving these for people with chronic problems. Oil in your distributor.
It's happened to me twice over 5+ years. I know it happened to Andrew. I also know the 2002 guys have had the same problem and I have not posted this yet on 2002 FAQ but will.
I know he only made a few and this idea is still not indorsed by 123 corporate in England.
If you have to have one contact Ed.

Gary
 
Gary - thanks a ton for posting the follow up about this. I have not had the problems you and Andrew have experienced, but I appreciate being aware of this issue, and the potential fix.
 
Yes, +1, thx Gary for the info.

FWIW, I have not experienced any issues with my recent 123 install, it seems to work great. However, I had only put about 400-500 miles on it before parking it for 'other reasons'....ugh.

Question: how many miles were acquired before noticing 'issues' ?!
 
shanon said:
Yes, +1, thx Gary for the info.

FWIW, I have not experienced any issues with my recent 123 install, it seems to work great. However, I had only put about 400-500 miles on it before parking it for 'other reasons'....ugh.

Question: how many miles were acquired before noticing 'issues' ?!
Click to expand...

My engine had 8000 miles on it with the first use. Over 4 years.
Rebuilt car and parts of engine then had failure. Sent to 123 charged me $250 to rebuild.
Put back in and drove less than 1000 miles and failed again.
That's when I did the research about the shaft.
I worked with them and they sent me a whole new circuit board that I installed myself.
BTW my motor is almost a race motor. Very modded.
Not sure it that has anything to do with it but actually needed the 123 for max performance.
So stuck out the research and process to get back.
HTH
 
I am reviving this thread as I am now battling this issue. My theory (besides the crank pressure one as noted above) is high oil pressure and I am asking the experts to confirm or debunk this possibility.

When I rebuilt my engine, the oil pump was also rebuilt and it works great. Hot oil pressure maxes out about 60psi at 4k rpm or so and 22 at idle. But after the engine had broken in and been running for a while, I noticed the dreaded oil seepage between the sandwiched circuit boards and oozing out of the cap. I removed the 123, cleaned the circuitry, and installed a new seal and bronze bushing. I already have the helical groove "upgrade" shaft - which now obviously isn't enough to hold back the oil. Yesterday, 6 weeks later, I noticed the issue is back after only a thousand miles or so.

My suspiscion started after the engine rebuild and before starting for the first time. I spun the engine with the starter (no plugs) to see if I had any oil pressure and if so, build it up before the first real start. I did this without the distributor in place and when I cranked it, oil shot out of the dizzy hole across the garage - not a drizzle, a significant shot that cleared the fender. I noted back then that if I ever had 123 oil intrusion that this may be the source. So here we are.

In summary:

1. I have the grooved drive shaft
2. I have new a bronze bottom bushing and shaft seal (looks like a mini transmission selector rod seal)
3. I have oil seeping before and after the latest 123 rebuild.
4. I have the valve cover breather hole venting with no restriction (other than the diameter of the hose attached to the fitting - hmmmm.....).
5. The only thing that has changed is the engine rebuild with higher compression pistons (10:1) and oil pump rebuild

Therefore, if it is the crank pressure:
1. High revs and/or high compression pistons overpower the ability of the valve cover hole to vent, possibly with, certainly without vacuum from the stock air cleaner, thereby driving oil up the 123 shaft past the groove and seal. Interestingly enough, I have little to no condensed oil at the bottom of my valve cover vent tube so a large amount of blowby is not evident. I may try a larger diameter hose but I suspect this will not have any effect.

If oil pressure:
1. High oil pressure, especially cold 20W50, drives oil up the 123 shaft past the groove and seal

Any thoughts on the above? I love the tech of the 123, and given BMW is the only engine with this issue as far as I can tell (I've searched other forums), I'm not ready to fully blame the 123. Yet.

I'll be cleaning this again AND thinking of a possible fix.
 
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