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Wed Aug 11, 2021 12:30 pm

Found this info

BUS
Dec 53 - Jan 54 VJ4BR2
Feb 54 - Aug 54 VJ4BR3

I have a VJ4BR2. My bus is an Apr 54 so should have a BR3 if this info is correct. What is the difference between a BR2 and BR3?

Wed Aug 11, 2021 1:23 pm

sgellis wrote: Found this info

BUS
Dec 53 - Jan 54 VJ4BR2
Feb 54 - Aug 54 VJ4BR3

I have a VJ4BR2. My bus is an Apr 54 so should have a BR3 if this info is correct. What is the difference between a BR2 and BR3?

https://www.instagram.com/p/CErBd4Xi7Un/?utm_medium=copy_link

Wed Aug 11, 2021 4:46 pm

Far as I can tell they look identical on the exterior. Probably just a different timing curve. Guess I will use it then.

Wed Aug 11, 2021 6:00 pm

TASB or some other users may be better able to answer this question, I have seen it covered in the Oval forum. That being said, the BR2 is a super rare distributor I believe they were used at the very beginning of 36hp production for about a month. Not many people have one of those.

Thu Aug 12, 2021 12:47 am

Correct, very rare. According to that link it states that the BR 3 is "without negative pressure connection" which I think is simply implying that it was mechanical advance only without vacuum advance for Bus engines. The same can be said about the VJ 4 BR 2. Going from an ancient memory here, but I believe Progressive Refinements lists the difference between the VJ 4 BR 2 and 3 as the 3 is "less noisy". I can't see where that matters one wit once an engine is running how noisy the distributor is :wink:

I'm busy the next two days but if I can remember I will run my VJ 4 BR 2 and then 3 on my Sun machine and we can compare and contrast both. I happen to have one of each in my distributor geek collection :shock: I know they are very close matches using the same tune up parts and possibly advance weights. They might have different advance springs in them.

I would be appalled to find that you had the audacity to run an VJ 4BR 2 distributor instead of a VJ 4 BR 3 :lol:

I ran my 1941 distributor in my oval for awhile along with a star coil, just to show that it could be done!

Thu Aug 12, 2021 12:58 am

They possibly meant better radio white noise suppression. maybe a slightly larger condensor or such.

tasb wrote: lists the difference between the VJ 4 BR 2 and 3 as the 3 is "less noisy". I can't see where that matters one wit once an engine is running how noisy the distributor is :wink:

Thu Aug 12, 2021 1:01 am

Yes, you may have hit on something there. I know on later distributors starting around 1959, with a screened rotor the part number badge ended in a "R". We are talking fairly early distributors here. The condensers would have been the same part.

Thu Aug 12, 2021 1:51 am

BR2 use ZPT 213/12 X and ZPT 214/1 Z Centrifugal weights
BR3 use ZPT 213/12 X and ZPT 214 Z 23 X Centrifugal weights

BR2 use 2pcs of WSF 89 Z 36 X springs (19.5 turns)
BR3 use WSF 89 Z 28 X and WSF 89/8 X springs (19 and 22 turns)

I can look if I spot any other difference in the parts book, but I think for example they used the same cam/rotor assembly.

If I remember correct it was general engine noice that was reduced (thus maybe hinting that it was the advance that changed) or maybe it was the same but springs/weight change ment the advance rattled less?

Thu Aug 12, 2021 2:35 am

I also have an earlier source indicating that early 383 used different springs.

Thu Aug 12, 2021 6:13 am

Wow, there you have it. Thanks for the data Frederik. Almost takes the fun out of testing the distributors on the Sun machine.

Thu Aug 12, 2021 8:39 am

The comments about BR2 and BR3 in the factory manual was about engine noice and using them on flat top piston engines/ changing to flat top pistons, 6.6:1 comp. ratio and then reduce initial timing (2.5deg BTDC above 80 octane fuel, 0deg below 80 octane for BR2 and 5deg BTDC >80 oct. fuel, 2.5deg BTDC <80 oct. for BR3).

The book is for type 1 VJU 4 but it shold probably be the same for the centrifugal VJ 4 models as well. In the comments it's said BR2 with it's lower timing will lose about 4% power up to 1800rpm, 2200-2400rpm a very small power gain to again loose some power in higher rpm. With a BR3 you will also lose some small amount of power and get some lower mpg, but this would hardly be noticed. For both BR 2 and 3 the engine noice will be louder, more so with a BR2.

I don't have an advance curve for VJ/VJU 4 BR 2, but this is for VJU 4 BR3 (the mechanical advance should probably be the same as VJ 4 BR 3). Initial timing for 6.1:1 ratio.

Fri Aug 13, 2021 7:03 am

Great info. Looks very usable on a 36. I actually hope to build a 30 anyway.

I would prefer a BR3 to match my April/13 build date. And I am not a distributor geek :) So if I was to trade my BR2 for a BR3 what would be the value difference. Is a working VJ4BR2 for a nice restored VJ4BR3 reasonable? I have no idea what either are.

Fri Aug 13, 2021 7:34 am

A 36hp and a 30 are the same engine, the 1192cc engine was introduced to replace the 1131cc in the very end of 1953. 30 is the european designation while 36hp refers to SAE (american) hp designation. This leads to confusion sometimes, so much that some reference books mistakenly refer to a 30hp as a 1 year only engine. The only difference between a 30 and a 36 is one of marketing as the VW began to more aggressively pursue North American Sales and to expand distribution across the United States, this became especially true beginning in the later part of 1954.

Fri Aug 13, 2021 7:54 am

Mr. OGPaint wrote: A 36hp and a 30 are the same engine, the 1192cc engine was introduced to replace the 1131cc in the very end of 1953. 30 is the european designation while 36hp refers to SAE (american) hp designation. This leads to confusion sometimes, so much that some reference books mistakenly refer to a 30hp as a 1 year only engine. The only difference between a 30 and a 36 is one of marketing as the VW began to more aggressively pursue North American Sales and to expand distribution across the United States, this became especially true beginning in the later part of 1954.

I thought the 30 was used to describe the early 36 with dished pistons and different compression ratio. And yes there is a lot of conflicting information on this.

So I will reword the previous statement as - I hope to build an internally correct 36 for April 54. :)

Sat Aug 14, 2021 9:56 am

The only people who would value a VJ 4 BR 2 over a VJ 4 BR 3 would be a distributor geek :wink: which is a very very small number or someone with a December 1953 /January 1954 Bus AND only wants month and year correct parts, possibly an even smaller number 8)