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Full Version: What makes a SVDA distributor less terrible than the 009?
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Tdskip
I know there’s about 1,000,001 variations of the distributors on these cars, and I’ve also read here that the Pertronix Distributors are clones of the much hated 009 distributors. Is the SVDA unit they sell considered acceptable because it has a better curve than their other units?

D186504 Flame Thrower distributoR

Thanks!
nditiz1
QUOTE(Tdskip @ Aug 18 2020, 07:13 AM) *

I know there’s about 1,000,001 variations of the distributors on these cars, and I’ve also read here that the Pertronix Distributors are clones of the much hated 009 distributors. Is the SVDA unit they sell considered acceptable because it has a better curve than their other units?

D186504 Flame Thrower distributoR

Thanks!


So the SVDA, like the one I'm selling is better than the 009 because it smooths the acceleration. Although it should be understood it is in fact the same curve as the 009 with an added bonus. It does this because during the transition from the idle circuit to the main circuit with carbs the mixture starts to go lean. When your mixture is lean its good to increase timing. The vac pod on this setup does this. You can, and a lot do, bypass the 009 "flat spot" by richening up the mixture with bigger jets. With the svda you can keep your accurate jets, but create no flat spot. With light throttle and the teetering point between idle and main the svda jumps the timing higher than the 009. When you open the carb butterfly more and pretty much erase the vacuum that exists it will bring the timing back to its full advance, 27-28 degrees. Hope that helps.
Tdskip
Thanks for the information.
IronHillRestorations
The only thing I don't like about the Pertronix SVDA is it's exclusively for a Ignitor and you can't put points in it. So for me (who has Ignitors fail in my bare hands) it's not my first choice, but it's got a good advance curve and is new.
Ansbacher
QUOTE(IronHillRestorations @ Aug 18 2020, 01:18 PM) *

The only thing I don't like about the Pertronix SVDA is it's exclusively for a Ignitor and you can't put points in it. So for me (who has Ignitors fail in my bare hands) it's not my first choice, but it's got a good advance curve and is new.


The solution to that is to carry a standby 009 dizzy with points. If the SVDA fails, pull it and throw in the standby.

Ansbacher
Tdskip
QUOTE(IronHillRestorations @ Aug 18 2020, 12:18 PM) *

The only thing I don't like about the Pertronix SVDA is it's exclusively for a Ignitor and you can't put points in it. So for me (who has Ignitors fail in my bare hands) it's not my first choice, but it's got a good advance curve and is new.


@IronHillRestorations - I’m personally more concerned about the curve and drivability than being able to swap points in. Compared to the Mallory units or getting a 050 rebuilt you can buy two of these and keep on as a spare.

It is a touch concerning that people have a variable experience with these products, personally I’ve been lucky but....
IronHillRestorations
If you want a vacuum advance carb, just get one from a 1.8, for that matter it's got (IIRC) 5* of vacuum retard on the other side of the dashpot
bbrock
Can anyone enlighten me on why the 1.8L dizzy is the preferred stock dizzy for carbs? Is it the lack of injector trigger points or is the curve better? I've looked at the specs on the 1.8 vs 2.0 but don't know enough to understand if the differences would significantly affect performance.

Click to view attachment
davep
022 905 205 T is the (unlisted on your pages) correct distributor for the 1.8V (V=Vergasser or carb version). This was the European 1.8 AN engine with carbs.
bbrock
QUOTE(davep @ Aug 18 2020, 02:50 PM) *

022 905 205 T is the (unlisted on your pages) correct distributor for the 1.8V (V=Vergasser or carb version). This was the European 1.8 AN engine with carbs.


Is that the one people are using for carb conversions? I got the impression they were re-purposing dizzies from L-Jet cars for carbs but maybe I have that ll wrong.
nditiz1
Is the European 1.8 version a DVDA or SVDA?

Not sure you would need the dual vac.
Tdskip
QUOTE(bbrock @ Aug 18 2020, 04:41 PM) *


Is that the one people are using for carb conversions? I got the impression they were re-purposing dizzies from L-Jet cars for carbs but maybe I have that ll wrong.


No, I’m with you on that understanding.
bbrock
QUOTE(nditiz1 @ Aug 18 2020, 03:44 PM) *

Is the European 1.8 version a DVDA or SVDA?

Not sure you would need the dual vac.


I've found this tech article on aircooled.net pretty informative on dizzy choices. https://www.aircooled.net/vw-distributor-options/

Here's what they say about DVDA.

QUOTE
DVDA = Dual Vacuum, Dual Advance Distributor. The same as the SVDA, but also has a Vacuum RETARD port. One vacuum port is for advance, the other is for an idle retard, which improved emissions a lot!


I've also read it can help smooth the idle in some cases.
Tdskip
There’s one more moving part here that we haven’t really talked about, which is that if you send one of these out to get rebuilt most rebuilders can set the curve up to be whatever you want.

It does make me wonder however if at the point in time that you buy a distributor core and then ship it back-and-forth to rebuild her and pay the rebuilder for his/her time if you aren’t in a 1 to 3 distributor price zone at that point anyway.
djway
You can replace the Dual can with a single so if you find a dual distb with a bad retard can or don't want the extra timing step just change it out.
This thread set me up for hours of reading about the dual now I have a headache ;O
I am considering switching to singles instead of blocking off the retard port after all I read.
bbrock
So far I haven't read any downside to using the vacuum retard other than having one extra hose to hook up. I figure if it reduces emissions without robbing performance, why not?

I have read that you should not block it off if you don't use it because that will affect the advance side too. Someone on my thread (Dave Darling?) said on some 914 models, there was a hose connected to the retard port that was just routed to some hidden place and not connected on the other end.
Al Meredith
QUOTE(Ansbacher @ Aug 18 2020, 10:43 AM) *

QUOTE(IronHillRestorations @ Aug 18 2020, 01:18 PM) *

The only thing I don't like about the Pertronix SVDA is it's exclusively for a Ignitor and you can't put points in it. So for me (who has Ignitors fail in my bare hands) it's not my first choice, but it's got a good advance curve and is new.


The solution to that is to carry a standby 009 dizzy with points. If the SVDA fails, pull it and throw in the standby.

Ansbacher


I build my own engines and have an engine stand for run-up. I have electronic dizys but I always time a 009 with points as a spare to carry with me incase the electronics fails.
djway
QUOTE(bbrock @ Aug 19 2020, 06:48 AM) *

So far I haven't read any downside to using the vacuum retard other than having one extra hose to hook up. I figure if it reduces emissions without robbing performance, why not?

I have read that you should not block it off if you don't use it because that will affect the advance side too. Someone on my thread (Dave Darling?) said on some 914 models, there was a hose connected to the retard port that was just routed to some hidden place and not connected on the other end.

Understanding that I was reading comments on the Interweb but there was all sorts of things about how to properly time and couldn't find agreement on where to hook the retard side for vacuum.
None of my throttle bodies have a second port so all I can find is the plenum and T off of the line that goes to the pressure regulator.
porschetub
The 009 throws in advance too quickly and generates a flat spot before transition,it was never setup to do anything else as it was originally designed for industrial motors,the early T1 industrial motors used the old cast-iron 010 model,seem to remember the 009 was used on the later stationary motors which if memory serves me were 1600 cc the early ones were 1200cc like the one I had in my fun buggy.
These units were controlled by a crank driven governor which mechanically bought the rpm up to max after load was applied,the T4 industrial motors I know nothing about but believe they built many mainly for generator units.
The current SVDA is an off shot of the 0231 170 034 used on 1600 T1 beetles and they worked great and will do on a t4 if you have a correct carb vacuum supply.
Some say the 050 was a better solution but never used one so no comment.
The current SVDA won't play well with a cammed large bore T4 so its down to a 009 and just put up with it,no one offers a recurve on these as far as I know,good luck.
Tdskip
Good morning/evening mate, hope you’re doing well. Thank you for the detailed response.
djway
The vacuum is to smooth the transition and some of the available distributors are 009 curves with a can so you should be able to get both of the best...ish.
I just hooked up a dual advance to a motor I will be firing up tomorrow, hopefully.
I need to move the distributor drive gear a few degrees so the can clears the injector on the plenum then I am ready to test fire.
Looking for good Karma smile.gif
Tdskip
Let us know how it goes.
IronHillRestorations
QUOTE(djway @ Aug 20 2020, 04:51 PM) *

The vacuum is to smooth the transition and some of the available distributors are 009 curves with a can so you should be able to get both of the best...ish.
I just hooked up a dual advance to a motor I will be firing up tomorrow, hopefully.
I need to move the distributor drive gear a few degrees so the can clears the injector on the plenum then I am ready to test fire.
Looking for good Karma smile.gif


Is it a L Jet?
djway
Yep.
Not triggered here smile.gif
porschetub
QUOTE(Tdskip @ Aug 21 2020, 02:11 AM) *

Good morning/evening mate, hope you’re doing well. Thank you for the detailed response.

always welcome Tom not always accurate but @ times my brain wakes up lol-2.gif lol-2.gif .
The 010 was a good unit and I ran one on my modified T1 motor in my 73 bus after using a 009 ,found the flat spot was way less ,thinking they had a slower early advance ramp as they were used in the early Kombi's.
The 009 is pretty much all we have for carbs motors so sort of stuck there.


IronHillRestorations
I'm working from memory as well, which for me is dangerous; but I think the 1.8 had 5* of retard at idle with the retard side of the dashpot connected, so potentially you could get a total of 37* with both dashpots. That said, I've never hooked up one like that, just with the advance side.
Tdskip
I know Glenn Ring rebuilds Porsche distributors, are there other sources as well?
BK911
I put a 009 in my 1.7 when I converted to dual carbs.
10 years later and still going strong.
No flat spot, no hesitation, just good acceleration through the gears. (For a 1.7!)
Maybe I'm just a better engine tuner than you guys? sheeplove.gif
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