Distributor part numbers

GPD

Greg
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Does anyone know an easy way to reference whether a later part with a new part number can replace the original OEM part number for the car?
I am looking to replace my distributor in my 1972 Bavaria. Real OEM part number 12111361236
I cannot find that part specifically, but have come across a number of distributors including Ed’s with part number 0231184008.
Ebay has some in Germany which is says would fit, eg. 0231306001 but I am not sure I trust ebay.

Would appreciate a resource and or some help.
greg
 

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Patience here, but when I put the numbers in do I specify my model etc or just search with the part number. I am reading the part number off the actual distributor (ed) and on another on ebay. So those parts might fit but are not original BMW parts?
 

coupedegrace

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Patience here, but when I put the numbers in do I specify my model etc or just search with the part number. I am reading the part number off the actual distributor (ed) and on another on ebay. So those parts might fit but are not original BMW parts?
I think the problem is that you're trying to use Bosch's (or whoever the OEM was) internally assigned part number as if it's a BMW part number. BMW assigns their own part numbers to the parts that they source from their suppliers. So in this example, BMW would use one part number for that distributor, and the OEM manufacturer would use their own, different number.

Check this little tutorial/FAQ out. Quite handy.
 

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That is definitely helpful. And they were the first folks I called when I started this process almost a year ago. My new question then is how to cross reference a Bosch part with a BMW part number. I suspect the “part store” can tell me but how to they look it up?
I think the problem is that you're trying to use Bosch's (or whoever the OEM was) internally assigned part number as if it's a BMW part number. BMW assigns their own part numbers to the parts that they source from their suppliers. So in this example, BMW would use one part number for that distributor, and the OEM manufacturer would use their own, different number.

Check this little tutorial/FAQ out. Quite handy.
 

HB Chris

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You don’t need to specify model or it will limit your search but I do select Classic. One used to be able to search a Bosch part number data base.
 
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halboyles

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Here is the distributor list from the "Engine-Electrical" section of the repair manual. It shows both Bosch and BMW numbers. In that same section you will find some useful advance curves and other specifications.
 

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I avoid ALL of this headache and send ALL my distributors to "Advanced Distributors" in Minnesota to have them rebuilt and curved. You can have him curve just about any advance you want, and the end result is more precise than the original. I hav been SUPER impressed with his ability. I've sent him distributors ranging from lowly 2002 ones to Gullwing 300SL units...and they come back working flawlessly. Cost is generally under $300 and turnaround time is 10-14 days, depending on how busy he is.

For the record: I'm not a huge rabid fan of the fancy digital 1-2-3 distributors. I think people are replacing completely whacked out junk original Bosch / BMW ones for the 123 stuff and of COURSE they'll be a fantastic improvement over 50 year old broken crap.... but a *properly* dialed in analog Bosch unit will work just as well (unless you invest time in a dyno session or three...the programmable feature of the 123 is virtually useless IMHO. )

Hope this helps!
 

halboyles

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"Advanced Distributors" in Minnesota
I definitely agree with Paul on this. You can specify the engine specs and performance expectations and you will get back a dizzy that will work with those specifications. The limitation is that if you change the cam/compression/fuel delivery/ignition, the distributor will no longer be perfectly tuned for the new configuration. Also, when you get the distributor, it will come with a single advance/rpm spec that you tune to, like "18° at 2000". And Jeff is reticent to share any other advance information. But, as Paul says, if you are going from a 40 year old Bosch to a rejuvenated Bosch, the difference will be night and day.
I do think that the 123Tune products offer a similar advantage in that you are exchanging a worn out part for a new one. And with the help of an AFR gauge and all the experimentation that has been done on the M10s and e9s, you can get a very good curve depending on your performance expectations. In addition, if you end up changing from downdrafts to sidedrafts or throwing in a hot cam, you can just adjust the curve to accommodate the new components.
If you are using an adjustable advance timing light and notice that the little flywheel ball is bouncing around like a Missouri meth addict, you will benefit by replacing the ancient worn distributor with either of these options I believe.
 

Stevehose

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For triple Webers you can set the throttle valve where they need to be in relation to the first progresion hole in order to eliminate the dreaded off-idle hesitation, then adjust the advance curve to dial in whatever idle rpm you want and not mess with the idle screw. It's a game changer. Then with jetting changes and a dyno you can adjust timing curve accordingly to get max performance. No can do with a mechanical distributor without a recurve each time.
 
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For triple Webers you can set the throttle valve where they need to be in relation to the first progresion hole in order to eliminate the dreaded off-idle hesitation, then adjust the advance curve to dial in whatever idle rpm you want and not mess with the idle screw. It's a game changer. Then with jetting changes and a dyno you can adjust timing curve accordingly to get max performance. No can do with a mechanical distributor without a recurve each time.
I've been able to solve the classic "off idle hesitation" by altering idle jets and em tubes generally - but you make a very good point, with regard to adding heaps of initial advance to keep the throttle happy. I tell Geoff at Advanced Dist what I want at idle and what I want total advance to be, and thus far the recipe has worked. The 123 is a great concept, but I still do not trust them 100% and I'm not ready to spend $$$ on dyno time....YET. :D
 

halboyles

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I still do not trust them 100%
I trust them 100% in the exactly the same way I have always trusted any electronic ignition: I keep the original mechanical distributor/coil/resistor already set up and ready to go in a sealed plastic bag under the rear seat!
 
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I trust them 100% in the exactly the same way I have always trusted any electronic ignition: I keep the original mechanical distributor/coil/resistor already set up and ready to go in a sealed plastic bag under the rear seat!
I 100% feel this, Hal! I just drove it 9 hours to Boston yesterday.... and this is among the few spares I packed in the trunk:
 

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Stevehose

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Yes a spare 123 is in my box of misc. breakdown items I take on long trips. I always keep an extra fuel pump under the spare tire.
 
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