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Thu Mar 16, 2017 4:12 pm

Hello,

Does anyone have the specs (advance curve plot) for the mechanical and vacuum advance of the Bosch VJU 4 BR 8 distributor? (Stndard distributor for oval-era engines)

Thanks in advance.

Thu Mar 16, 2017 4:24 pm

Yes, I'll post it later when I get home.

Thu Mar 16, 2017 4:25 pm

Thanks. I appreciate this a lot.

Thu Mar 16, 2017 4:29 pm

This was in the gallery, I should have one with both mechanical and vacuum at home.

Fri Mar 17, 2017 1:44 am

Thanks.

I would be interested to know the degrees of advance for the vacuum unit as well, and if possible the value of the vacuum depression itself.

Fri Mar 17, 2017 3:54 pm

Tagging along, I just cleaned one of these up (0 231 115 040, actually, but who's keeping track :roll: ) and was curious what it should be at. Other than dirt and external rust, it looks NOS inside and is nice and tight.

Fri Mar 17, 2017 8:01 pm

Komissar wrote: I would be interested to know the degrees of advance for the vacuum unit as well, .

in my own little "gallery" here's the vacuum and centrifugal:

Sun Mar 19, 2017 7:33 am

The vacuum canister delivers between 8 and 12 degrees of advance.

Tue Mar 21, 2017 1:55 pm

There is a small difference early and late vju4br8, this is early (before mars 1956/ date code 3M).

Sun Mar 26, 2017 12:08 pm

Here is some numbers from "Notes on the Practical Work" #13 a Volkswagenwerk Service School publication posted here on theSamba.

These motors don't run much advance as it looks like the later 36 horse distributor only has 14-20 degrees of centrifugal advance all in up around 3200-3600 rpm. The vacuum advance is 7 to 13 degrees. Total advance under load would then only be 21.5 to 27.5 degrees and max total advance only 28.5 to 40.5 degrees (wow, quite a range.)

Mon Sep 10, 2018 1:53 am

Yes, but good for folks to realize that distributors have an aceptable range in their performance.

I've always quietly considered it overkill for data tables to suggest that distributors like the 1966-1967 models to be static timed at 7.5 degrees static. Few of us have the ability to set timing to that degree of accuracy. That explains the reasoning for the notches in the pulley.

Tue Sep 11, 2018 5:58 pm

EVFun, where did that data table you posted come from? Looks to be old factory parts/repair manual but I've never seen one with the intermediate advance data before.

Tue Sep 11, 2018 6:31 pm

Some notes on the distributors in that table:

VJ,VJU 4 BR 2- was a short lived distributor version running less than 8 weeks starting December 1953.

VJ,VJU 4 BR 3 Basically the same distributor but with modified advance weight springs. Also short lived Janaury to July 1954. The VJU 2 and VJU 3 shared the same vacuum canister.

VJ/VJU 4 BR 8 date codes 2 and 3 M correspond to February and March 1956. The VJ 4 BR 8 was re-released in the mid 1960's as the "019" and "screamer".

211 905 205 B Interesting that they have included data for this uber rare distributor made by Garbe Lahmeyer in very limited numbers. This is the mechancial advance version of the "VW" distributor.

ZV/JUR 4 R 1 used in 1959 for just a few months only on Ghia's.

VJ 4 BR 25 released for 1960 Bastard 40 hp Bus re-released later as the "010". I've never seen a 211 905 205 H, and I don't think its a Garbe Lahmeyer unit so maybe the VW# for the BR 25? In the late 1960's it was badged as a 211 905 205 F along with the 010 designation.

113 905 205 B was the service department replacement for the 113 905 205 K used for 1966-67 Beetle and Bus.

ZV/JCU 4 R 3 the last of the cast iron SVDA distributors this one installed on type III for 1964.

113 905 205 P is a VW part # but then it's listed as Bosch! This was the first of the aluminum bodied SVDA's installed on 1968 semi-auto transmission Beetles.

Mon Sep 24, 2018 8:35 pm

tasb wrote: EVFun, where did that data table you posted come from? Looks to be old factory parts/repair manual but I've never seen one with the intermediate advance data before.
It is in the Technical tab near the top of theSamba. In there you will find a section titled "Technical Instruction Manuals." In that list click on "Notes on Practical Work" and scroll down to Subject 13 "Ignition system." There is a lot more to that manual than just the advance curves for distributors.

I've been crawling through that whole section, slowly, and there is a lot of interesting stuff there!

Tue Sep 25, 2018 9:11 pm

Thanks for the directions!