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75-911S
Samba Member
Joined: May 22, 2010
Posts: 25
Location: Hartsville, SC
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 Posted: Thu May 08, 2025 1:41 pm Post subject: Wht's the Correct Timing? |
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The Bently manual indicates the motor numbers beginning with the B code were 1600s with single port heads produced from August 1969 to August 1970 and calls for these engine to be timed at 0 degrees TDC. Motors after August 1970 began with the AE code and were dual port models and were timed 7 1/2 degrees before TDC.
I have a 1600 engine in my ’66 T1 with a B code that the PO ungraded to dual port heads and switched to the dog house air shroud. It also has a much later distributor (0231170034) which is a SVDA.
How should I time this engine (zero degrees TDC or 7 1/2 degrees BFTDC)? |
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Glenn 
Mr. 010
Joined: December 25, 2001
Posts: 79446
Location: Sneaking up behind you
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| Posted: Thu May 08, 2025 1:55 pm Post subject: Re: Wht's the Correct Timing? |
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| 75-911S wrote: |
| It also has a much later distributor (0231170034) which is a SVDA. |
28-32* BTDC @ 3500 rpm with the vacuum hose disconnected and the carb port plugged.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
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KTPhil
Samba Member
Joined: April 06, 2006
Posts: 35871
Location: Conejo Valley, CA
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| Posted: Thu May 08, 2025 2:51 pm Post subject: Re: Wht's the Correct Timing? |
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It's a bullshit question.
Link
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scarabee
Samba Member
Joined: May 14, 2021
Posts: 155
Location: South Africa
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| Posted: Fri May 09, 2025 1:36 am Post subject: Re: Wht's the Correct Timing? |
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| Now I have to watch that movie again! |
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75-911S
Samba Member
Joined: May 22, 2010
Posts: 25
Location: Hartsville, SC
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| Posted: Fri May 09, 2025 5:15 am Post subject: Re: Wht's the Correct Timing? |
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| Why is it a bullshit question? I really wanted to know. |
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tasb
The Distributor Distributor
Joined: April 27, 2002
Posts: 6743
Location: Pentwater, Michigan
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| Posted: Fri May 09, 2025 5:48 am Post subject: Re: Wht's the Correct Timing? |
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May have something to do with the irrelevant details in your post. Follow Glenn’s instructions and when done check your advance. With that distributor you should be somewhere around 8 degrees advanced.
You could also reverse the procedure and set initial timing at 8 degrees and then verify that full advance does not exceed 32 degrees.
Besides the distributor number and what carburetor for distributors with vacuum advance, you don’t need all the other details like engine code.and head size, dog house and etc.
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Last edited by tasb on Fri May 09, 2025 6:40 am; edited 2 times in total |
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75-911S
Samba Member
Joined: May 22, 2010
Posts: 25
Location: Hartsville, SC
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| Posted: Fri May 09, 2025 6:17 am Post subject: Re: Wht's the Correct Timing? |
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| Thanks for your useful reply. |
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tasb
The Distributor Distributor
Joined: April 27, 2002
Posts: 6743
Location: Pentwater, Michigan
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| Posted: Fri May 09, 2025 6:45 am Post subject: Re: Wht's the Correct Timing? |
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We should treat each other with more kindness rather than less.
_________________
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
Member# 2059
Last edited by tasb on Sat May 10, 2025 4:42 am; edited 1 time in total |
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Glenn
Mr. 010
Joined: December 25, 2001
Posts: 79446
Location: Sneaking up behind you
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| Posted: Fri May 09, 2025 8:18 am Post subject: Re: Wht's the Correct Timing? |
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| 75-911S wrote: |
| Why is it a bullshit question? I really wanted to know. |
Watch the video. In it the prosecutor asks the firing order of a 57 Chevy with a 327 and 4 barrel. Problem is the 327 was not an option of the 57, the 260/283 was the largest engine.
Humor doesn't always work on the interwebz.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"
Member #1009
#BlueSquare
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mukluk
Samba Member
Joined: October 18, 2012
Posts: 7452
Location: Clyde, TX
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| Posted: Fri May 09, 2025 8:48 am Post subject: Re: Wht's the Correct Timing? |
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| 75-911S wrote: |
| Why is it a bullshit question? I really wanted to know. |
It was meant as a joke, with a clip from the movie it's from included for context. Jokes don't always come across well on the internet unfortunately.
Information in books for "such and such series engine uses X timing while this other series uses Y timing" is less useful as the years pass because that information is based on the assumption that the engines are original/correct for that year range or engine series. Many of these cars, if not the majority, have by now had numerous bits swapped out over the years in the interest of simply keeping them going or upgrades, taking them away from originality. As such, it's useful to know what's been changed and I applaud when people make an effort to include that information -- it sure beats playing twenty questions to try to pry pertinent info out that could've been provided upfront and saved a lot of time. A key point from there is to not get hung up on the extra included details that turn out to not be relevant to the question at hand.
For your timing question it's useful to understand that for the typical VW engines discussed here (no forced induction or exotic fuels), the base timing setting you'll use is determined by what distributor you have installed. Other engine details don't really affect that, though the extra details may help clue in that you might have a mismatch that won't work well.
In the case of an SVDA distributor, most often it's recommended to use the total/full in timing method recommended earlier due to there being so many aftermarket units of questionable quality and worn out originals, either of which being likely to not give the proper amount of advance if timed per a book spec at idle.
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tasb
The Distributor Distributor
Joined: April 27, 2002
Posts: 6743
Location: Pentwater, Michigan
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| Posted: Fri May 09, 2025 11:02 am Post subject: Re: Wht's the Correct Timing? |
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Of course it was meant as humor. It really needed more context though. I actually use humor as one of my tools when I am speaking to a group. In those situations I can make eye contact and it's possible to "read" the audience and make adjustments. Can't do that nearly as effectively on here or elsewhere on the web. I'm also aware that newbies need a gentler hand. The OP's post count was pretty small.
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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
Member# 2059 |
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75-911S
Samba Member
Joined: May 22, 2010
Posts: 25
Location: Hartsville, SC
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| Posted: Fri May 09, 2025 1:15 pm Post subject: Re: Wht's the Correct Timing? |
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To fill in some info about me: I'm a former Porsche powner (3 of 'em) and long time Formula V racer back in the day. I actually stripped down and rebuilt the twin cam motor in my '75 911S. I have lots of experience with 1200s (via Formula V), many motorcycle tear-downs and rebuilds (including a WWII BSA), a classic Mini Cooper restoration, a '51 Willys military Jeep restoration, and others. Needless to say I'm a bit long in the tooth, but this is my first 1600DP. So I'm gonna have questions, many that might seem dumb to the knowledable folks. I hope you'll help me when I can't find answers in the Bently and Haynes manuals or through reseach here.
Thanks
Jack |
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 16561
Location: North Florida, USA
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| Posted: Fri May 09, 2025 5:11 pm Post subject: Re: Wht's the Correct Timing? |
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Generally, you should base your ignition timing on the distributor (and in some cases the carb) installed on the engine. If you have an all stock engine that matches the model year of your car then go ahead and use the stock ignition timing VW recommended for that model year car and its model year engine. If you no longer have the original carb+distributor you should NOT be relying on the stock ignition settings.
Each VW vacuum advance distributor was mated with a specific carb to produce the correct vacuum signal for that distributor. It is very possible to mismatch the distributor with a carb that cannot produce a usable vacuum signal. For example, early carbs would produce a left side vacuum advance signal in the range of 5-inHg. The later carbs matched to the SVDA and DVDA distributor would produce up to 20-inHg to fully advance the vacuum based timing. Pairing an early style carb (low vacuum) with a later style distributor (high vacuum) and your vacuum advance will do almost nothing for you.
Connect a later carb to an early style distributor and you could damage the (50-yr old) vacuum canister by applying too much vacuum.
Using a vacuum gauge and vacuum hand pump you can test both your carb and distributor to confirm how much vacuum is needed to advance the distributor and how much vacuum the carb produces. There are also tables that list the matching carb+distributor pairs that came in the different model year cars.
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AshMan40
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tasb
The Distributor Distributor
Joined: April 27, 2002
Posts: 6743
Location: Pentwater, Michigan
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| Posted: Fri May 09, 2025 6:43 pm Post subject: Re: Wht's the Correct Timing? |
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I’d noted that you’d been a Samba member since 2010, Jack and been lurking, so not a complete newbie.
Good synopsis from Ashman above, as usual. If you have dual port heads and an “034” distributor you should likely have a 34 PICT 3 Solex carburetor. It will have a flange number on it if it’s an original.
The “034” is the Bosch part number= VW part number 043 905 205 on the above chart
https://www.thesamba.com/vw/archives/manuals/Bosch_Tune_Up_Parts/Bosch_Tune_Up_Parts.pdf
And this link is for distributors. Both charts are thanks to Andy aka Glutamodo.
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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
Member# 2059 |
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75-911S
Samba Member
Joined: May 22, 2010
Posts: 25
Location: Hartsville, SC
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| Posted: Sat May 10, 2025 5:06 am Post subject: Re: Wht's the Correct Timing? |
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Great chart and info.
Since I have the 34 PICT 3 Solex carburetor and the 034 distributor I now have my answer. Thanks guys |
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ashman40
Samba Member
Joined: February 16, 2007
Posts: 16561
Location: North Florida, USA
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| Posted: Wed May 14, 2025 11:13 pm Post subject: Re: Wht's the Correct Timing? |
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| 75-911S wrote: |
Great chart and info.
Since I have the 34 PICT 3 Solex carburetor and the 034 distributor I now have my answer. Thanks guys |
All of the carbs in the above table are Solex 34Pict carbs... but they are NOT the same. Don't assume your 34Pict carb will work with your SVDA distributor. Ideally, you want a matched pair. The distributor numbers above are perfectly matched to the 34Pict carb with the listed base flange#.
What is your Solex carb base flange#?
The carbs matched to distributors with a factory timing of 5ATDC are carbs matched to a DVDA distributor. Those with timing of 7BTDC are meant to be matched with an SVDA distributor like yours. The hole in the throttle plate was larger on DVDA matched carbs to allow more air to flow past the closed throttle plate. Running an SVDA distributor with a carb designed to work with a DVDA distributor may not be ideal and you may struggle to get a good idle.
Read about it here:
Idle problems DVDA? SVDA? 34 Pict 3
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AshMan40
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'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!} |
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