Why does my 74 have a vacuum advanced distributor

[buckweber]

Attached shows vacuum advance working    

 

Appears to be be counter clockwise 

IMG_0131.MOV

[buckweber]

Dist #. 0 231 115 071

JFUR4

['76mintgrün'02]

yes it does.  that is vacuum advance, not retard.

 

researching the model number might give you some insight.

 

putting a timing light on it with the variable advance feature would let you plot its curve, while on the engine, or tell you what the all-in advance is with the BB set at various rpms.

 

 

 

[buckweber]

I don't have a variable timing light

[buckweber]

Would the best play be to replace the distributor?   And if so,  with what?

 

dont have much funding so if I can get it to work with what I have that would be preferable 

['76mintgrün'02]

ah.  well, do you have a dwell meter?

if not, that'd make two reasons to buy an Innova 5568 timing light.

that model also has a built in tach and volt meter.

shopping online will get one to your door for $100.

money well spent, imho.

timing is such a critical setting that it warrants proper tooling to assess the situation.

 

I did a tiny bit of googling to see if I could find info on that distributor, but did not have much luck.  Even if you found the factory curve for it, there is no guarantee that it is still working that way.  

 

Perhaps Carl could post the model number of his distributor and you could post a wanted ad, to find one.  Hard telling what condition another used one will be in... but having the light mentioned above will tell you what it's doing.  

 

edit:  do you know anyone with a variable timing light?  that might keep you from having to buy one right now.

Edited September 16, 2017 by '76mintgrun'02

[OriginalOwner]

My distributor is whatever part number they installed at the factory, it is 100% original.

 

My first source for parts (new or used) is 2002AD in Pomona, CA.  Call Ben to discuss and see what he's got ......

  https://www.2002ad.com/storeworks/view_item.cfm?id=1103

 

Cheers,

 

Carl

 

 

 

[Simeon]

Replace that with an Ireland Engineering mechanical only distributor. Be prepared to swap out the Pertronix styled magnetic proximity switching system. 

[Dudeland]

.... or a 123..... I hug and kiss mine daily.... please don't judge 

 

 

[Conserv]

19 hours ago, buckweber said:

Dist #. 0 231 115 071

JFUR4

 

Just trying to sort this out.  The above distributor has centrifugal and vacuum advance?  Correct?  And are we saying this model distributor was original to a 1974-76 U.S. model (which generally have centrifugal advance and vacuum retard)?  I don't know all the distributors used on 1974-76 U.S. models, but my 49-state 1976 came with a 0 231 170 164 JFU4, as below.

 

Is this currently on a '74 tii?  Is it possible it's been swapped out over the last 43 years?

 

Regards,

 

Steve

 

Edited September 17, 2017 by Conserv

['76mintgrün'02]

1 hour ago, Conserv said:

Just trying to sort this out.  The above distributor has centrifugal and vacuum advance?  Correct?  

 

And are we saying this model distributor was original to a 1974-76 U.S. model

(which generally have centrifugal advance and vacuum retard)?

 

I don't know all the distributors used on 1974-76 U.S. models, but my 49-state 1976 came with a 0 231 170 164 JFU4, as below.

 

Is this currently on a '74 tii?  Is it possible it's been swapped out over the last 43 years?

 

The above distributor has centrifugal and vac advance, correct. (0 231 115 071)

 

This model original to '74-'76?  Nobody has identified this model's original application (in this thread). 

(I don't agree with vac retard generalization for 74-76 cars)

 

It is currently on a '74 tii, according to the title of this thread.

 

It seems likely that it has been swapped out for the original, which had centrifugal/vac retard... such as the one on Carl's car (mystery model number). 

 

 

If I am not mistaken, the early tiis had centrifugal advance (only) distributors and in '74 they added vacuum retard.  As we have seen in the photo Carl posted, the vacuum supply line came through a "T" fitting (and I do not know the correct terminology to say where the hoses plug in).  Running vacuum advance on this engine does not seem like a good idea, especially because I do not understand the nature of the vacuum signal it is getting.  It seems safer to unplug the vacuum unit and cap off the source nipple(s).  Set all-in centrifugal advance to the tii safe-limit (32-34* btdc??) and see how it runs.

 

Setting the BB to some prescribed rpm setting is risky, without knowing what the total advance is at that setting.  A variable timing light is required to diagnose the situation.  If you do not have a dwell meter, the light mentioned above will be doubly useful.  Setting points with feeler gauges is not accurate enough, imho.

 

(If you do already have a dwell meter, there may be cheaper lights out there, which are variable, without the meter built in.  I have no experience with them though).

[PaulTWinterton]

We talked about this in my 74tii engine build thread.

 

JAS wrote:

The correct distributor for the 74 tii is 180013 and that one includes the dashpot which is attached to the decel valve mounted on top of the 74tii air cleaner. Interesting enough, Jeff at Advanced is adamant that the vacuum advance (s/b retard) on the 013 hurts performance. He said to plug the vacuum line to the dashpot, set the advance at idle to 12 - 15 degrees BTDC, and then leave it as is. I plan to try it both ways (factory and his) and see if there is much of a difference.

 

Thanks John.

 

In 74 they added the vacuum retard function as an emissions feature.  The vacuum hoses are connected to the air cleaner and the plenum via the T-fitting.  With the aid of a one-way valve (on the air cleaner) the vacuum is activated on decel, affecting the  spark/detonation of unused fuel in the cylinders while decelerating.  On acceleration or cruising the distributor acts on the mechanical advance only.

 

Right?  Anyone add or disagree, please.

 

 

[Conserv]

7 hours ago, '76mintgrun'02 said:

 

The above distributor has centrifugal and vac advance, correct. (0 231 115 071)

 

This model original to '74-'76?  Nobody has identified this model's original application (in this thread). 

(I don't agree with vac retard generalization for 74-76 cars)

 

It is currently on a '74 tii, according to the title of this thread.....

 

Tom,

 

I, too, believe buckweber's distributor is not original to his engine if he has a '74 tii, but was hoping to hear back from Carl, until Paul came through with the correct distributor number.

 

My authority for saying that all U.S. '02's from the 1974 through 1976 models utilized vacuum retard distributors is simply the U.S. '02 marketing brochures -- and, heaven knows, marketing brochures might have errors.

 

Below, nonetheless, are:

 

1.  1974 brochure (un-dated, but shows both 2002 and 2002tii sub-models)

2.  January 1975 ("1/75") brochure

3.  January 1976 ("1/76") brochure

 

Best regards,

 

Steve

 

 

 

 

 

 

 

Edited September 17, 2017 by Conserv

[Conserv]

4 hours ago, PaulTWinterton said:

We talked about this in my 74tii engine build thread.

 

JAS wrote:

The correct distributor for the 74 tii is 180013 and that one includes the dashpot which is attached to the decel valve mounted on top of the 74tii air cleaner. Interesting enough, Jeff at Advanced is adamant that the vacuum advance (s/b retard) on the 013 hurts performance. He said to plug the vacuum line to the dashpot, set the advance at idle to 12 - 15 degrees BTDC, and then leave it as is. I plan to try it both ways (factory and his) and see if there is much of a difference.

 

Thanks John.

 

In 74 they added the vacuum retard function as an emissions feature.  The vacuum hoses are connected to the air cleaner and the plenum via the T-fitting.  With the aid of a one-way valve (on the air cleaner) the vacuum is activated on decel, affecting the  spark/detonation of unused fuel in the cylinders while decelerating.  On acceleration or cruising the distributor acts on the mechanical advance only.

 

Right?  Anyone add or disagree, please.

 

 

 

Nice summary, Paul.

 

I would guess that the factory tuning specs achieve the lowest possible emissions, not the best overall performance.  So I'd guess that Jeff's specs will yield a performance improvement.  Please let us know!

 

Best regards,

 

Steve

 

[OriginalOwner]

OK, I'm reunited with my all-original '74tii .......  hope this stuff helps.

 

--  The number on the distributor body is of course facing the firewall and "impossible" to see.  Using 2 different mirrors and a flashlight, and reading everything backwards, I think I read this number:

      0 231 180 013

 

--  I found nothing at www.RealOEM.com  

 

--  SO, I Googled,   "2002tii  0231180013" and found these links ......

 http://www.vehiclepartsdatabase.com/vehicles/allprivateroadvehicles/bmw/02touring/2002tii/m10b20/7518/distributors/bosch/0231180013

 

 http://www.data.bmrparts.com/bmwparts/BMW_IGNITION/BMW_2002TII_2DR_E10_IGNITION_Distributor_3_12111357771.html

 

  GOOD INFO HERE,  see what visionaut writes .......  

 

 

Cheers,

 

Carl