Distributor #3 lobe retard discussion

[tasb]

There has been some discussion if you do a further search on whether some VW distributors have a retrd of @ 3 degrees built into the #3 lobe of the points cam to attempt to keep the engine cooler since the fan shroud on original single port type 1 and 2 engines has the oil cooler interfering in cooling air flow. I don't believe it has ever been fully researched "in the flesh" which distributors have this feature and which ones do not. As above there is some manual documentation out there but nothing with extensive real testing. I will attempt here to do some real world testing and post the results.

I plan on testing the following distributors on my 1949 Sun MSD Distributor Tester. I'm open to some educated suggestions if you believe there's another distributor version I should test.

ZV PAU 4 R 5 big cap 40 hp (March 1962) NO

ZV/PAU 4 R 6 big cap type III (Feb 1962) [NO)

ZV/JU 4 R 3 20 degree advance (9U Sept 1963) YES

113 905 205 B Garbe Lahmeyer (no date) maybe

111 905 205 N 20 degree advance (502 Feb 1965) YES

113 905 205 K short cap 25 degree advance (805 May 1968) YES

131 905 205 as above but exclusively for Bus (Sept 1968) YES

113 905 205 M short cap 32 degrees advance 1968 (708 Aug 1967) YES

113 905 205 T tall cap 32 degrees advance (Oct 1969) [YES]

315 905 205 B Service replacement (126 June 1971) YES

113 905 205 P autostick Beetle 1968

113 905 205 AJ DVDA Beetle (029 Sept 1970) NO

211 905 205 Q DVDA Bus 1971

113 905 205 AN DVDA Beetle YES tested 2 still a YES

113 905 205 AL SVDA for Europe (225 May 1972) maybe

0 231 174 001 1973 Porsche 914 NO

0 231 178 009 omnipresent (624 April 1976 German manufacture) NO

0 231 129 010 later 1960 Bus production (no date) NO

0 231 129 019 later 36 hp bus production (326 June 1973) NO

I will have to do some assembly to prepare 311 905 205, D,E,F,G, P, AD. UPDATE; I have 11x 311 SVA cores some dual spring but every single one of them will require some tear down before they will read stable enough on the Sun Machine to yield accurate results. I already know the results of some of these tests from experience but I will do the test and post the results none the less. Maybe one of the reproduction "034"' which I don't believe I have.

Edit: I'm using a distributor machine that is seventy - two years old and it's demarcated in one degree increments as found at the distributor rotation so 3 degrees of spark advance at the crank equals 1 1/2 degrees at the machine. That small of an increment is open to some error especially with my limited visual acuity. One should also consider the ware on points cam lobes. I've run NOS distributors and the difference is clear but on used distributors we are open to some interpretation. Maybe = need a second closer look.
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Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018

1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc

1961 (October)Single Cab- Road Trip Workhorse

[Glenn]

Please post the results in your first post so its all in one place.

If you can't edit it, pm me and I'll edit it.

Thus way it's easy to find the results.
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Glenn
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[Pruneman99]

The 113 905 205 T is the tall cap version of the M no?

If you happen to have a 311 905 205 F single or dual spring I'd like to see the results on that one.

[tommiebsmith]

I'd be interested in the results also..

Great start to answers that a bunch of people ASSUME they know already..

thanks for the time and effort.


I think a specific answer to start the thread to verify exactly where #3 should located on the distributor - based on the indicator on the housing and the location of the drive gear ..

we all know many have drive gears dropped in all over the place .. and to note the specifics of what "SHOULD" be may offset what is out there and what people are working with.

[tasb]

Respectfully, I'd like to post here as the other topic title will not lead anyone to this data while this title does.
_________________
Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018

1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc

1961 (October)Single Cab- Road Trip Workhorse

[KTPhil]

I've always though it odd that a Type 3 motor would have #3 retarded, since the cooling air issues is not the same as for the upright engines.

But perhaps the slight bleed off of oil cooler air (though it exits independently) makes #3 run hotter there, too?

Elfrink's manual makes it clear it does so. It will be good to see it in practice.

[evanfrucht]

[Glenn]

[sjbartnik]

My Type 3 has the 311 905 205 D and I can confirm it *does* have the built-in retard on cylinder #3.

Verified it with timing light vs. #1.
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1965 Volkswagen 1500 Variant S
2000 Kawasaki W650

[Onceler]

I’ve never understood why VW would purposely try and burn no.3 exhaust valve with less timing. I guess if there’s a knock due to lack of cooling maybe
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1972 Karmann Ghia

[busdaddy]

I eagerly await the results of this, so much speculation and so few facts right now.
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[tasb]

[tasb]

[Frederik]

I've posted this before, but this thread might be good to have it in as well:

[tasb]

So according to the above documentation the asymetric ( I like that term better than retarded) cam began with the 111 905 205 M. i don't think there was any difference between the 111 M and the ZV/JU 4 R 3 designation other than the part number but I will have to dig out one and run it to confirm. so far except for the above my finidngs are in line with the documentation.
_________________
Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018

1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc

1961 (October)Single Cab- Road Trip Workhorse

[Pruneman99]

This is great stuff. Thank you Tasb. There was always the mystery of the #3 retard, but the information was always so vague and unreliable. It's great to have actual test data.

Maybe try some 009s? I've heard both ways, especially on the non-Bosch aftermarket ones. It would be nice to see a sampling there.

[tasb]

Yeah, the uh oh nine conundrum. I try to keep the 009 cores to a minimum. Sold one at Prado for $10 yesterday just so's I didn't have to look at it anymore.
_________________
Roads Scholar &
1957 Kombi low mileage 36 hp governor equipped M 178 Slow Drag Winner 2014, 2015, 2018

1965 hardtop Deluxe Microbus owned since 1990 M 620 factory 12 v 1500cc

1961 (October)Single Cab- Road Trip Workhorse

[Zundfolge1432]

Sounds cool about the 009. I put out a call saying I would buy 009 cores a few years back. As expected talk is cheap all crickets out there in samba land.

[Frederik]

[oprn]

Excellent! Thanks for this!
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