SVDA 34 Dist.

I think the SVDA has a vaccum advance while the 009 does not. Many will claim the SVDA to be superior as the 009 will provide a "flat spot" on initial acceleration. This is not true in all cases. My very slight flat spot on the 1915 with the Weber 32/36 and 009 was cured with tweaking of the idle jet in combo with tweaking of the 009 advance. Others will say this is impossible.

Carl- You can buy new 034's; John at Aircooled.net will custom tailor the curve to your motor. I believe the difference is either single (it's designed to run with a 34-3 Solex) or dual carbs (a little more advance at idle/off idle).

http://vwparts.aircooled.net/A...butor-p/acn-svda.htm

There is a Pertronix points-replacement unit available as well.

Upon looking I see there are more options than I originally thought...

 

Kaddie Shack has them as well-

http://www.shop.kaddieshack.co...mit.sc?keywords=svda

 

They are, of course, available used; look in the swap meet area at any VW show. It probably would be a good idea to take apart, inspect and regrease  before using. Check the Samba advertisers for people and prices. Glenn Ring (Glenn on the Samba) refurbishes 010's and 019's, but as far as I know doesn't work on the newer aluminum bodied distributors, but may sell you the necessary pieces....

 

Advantages- It's a mechanical advance distributor with a vacuum can. At part throttle cruising the svda's vacuum advance unit adds several degrees of timing, and if the carb/carbs are jetted a little lean on the idle circuit(s) can result in better mpg figures (3-5?). And what David said...

 

Carl:  Don't forget that, while a lot of people find an SVDA distributor superior in every-day driveability, you'll need to provide a balanced vacuum signal for it.  This can be as simple as installing a threaded, 1/8" barbed fitting into BOTH intake manifolds, running stiff-walled vinyl tubing from both into a "T" and then a single tube from the T to the distributor.  You may, depending on which carburetor(s) you have, already have a vacuum port at the base of the carbs, so look for that first - it should have a rubber cap on it.   It should be lower than the throttle shaft when you're looking for it.

 

Some people dispute the need for tapping into both manifolds and insist that you only need to tap one side.  I have never done that but, theoretically, at least, there should be enough vacuum signal on one side to drive an SVDA distributor.  I would try it on one side and see how it performs and then decide.

 

Gordon

The Speedstah Guy from the haht of the snow belt

Thanks guys. 

Again, you came through with good advice & great information that flattens my learning curve!

 

This SVDA possibility skids to an abrupt stop!!

 

I'll contentedly limp along with my 009 'flat spot'@ 2,000rpm until the Suby conversion.

Very valuable comments posted before; may I also add that with SVDA's, the cars run a little cooler too. So if you add the characteristics of better driveability, cooler engine temperature and better gas mileage they're a no brainer for street driven cars. Racing cars are another matter so the .009's work well on those. I have dual Dell 40's but only one has the vacuum port so my SVDA is hooked up to the one and the car works very very well.

I've heard an 034 described as an 009 with the advance canister; not exactly true, but they do have "similar" mechanical curves.

 

David- I've read that (with the 34-3) as you're saying, the 009 off idle flat spot can be "cured" (hidden might be a better description) by increasing the idle jet size. Of course, mileage goes down. I'll look in my notes.

 

As Gordon said, tapping off one carburetor should be enough. Taking the vacuum from both carbs doesn't make the vacuum stronger; it evens out the pulses and (I'm guessing here) gives a more steady, solid signal to the vacuum canister.

 

 Impala, you hit the nail on the head! Any time an aircooled motor runs a little cooler means longer life, and of course more mileage means more fun per tank! In most racing situations you're either off or full throttle so a vacuum assist distributor wouldn't be of any use. At some point, too much camshaft duration disrupts part throttle vacuum and renders it useless in a street car, so if mileage is a priority it has to be taken into consideration. I've heard of guys getting a manageable vacuum signal with an Engle W120 cam (253' @ .050") but not with a W125 (263' @ .050"). I wonder if carbs being properly sized or a little big for a motor would have an affect?

 

Oh, 1 more thing...those that are running dual carbs and an svda; if you know any thing about the camshaft in your motor could you please tell me what you have? Any before/after comparisons? Thanks in advance. Al 

 

Stan- I know you tried different distributors; did you mess with an svda at all?

Al; in my case I run a stock cam with 1.25 ratio rockers. Motor is 1915 cc.

ALB, you are right, combining both sides smooths out the vacuum signal. Also you can build/buy a small reservoir to help with this too. I learned this from the Megajolt site with respect to MAP sensors. The SVDA dizzy with the right curve, cam, and carbs will work very well indeed.

Al, you're probably quite right that I didn't cure the flat spot but rather hid he bugger. I'm stubborn to a fault and cross that with trying to learn new things, I just dealt with the 009 that came with the 1915 engine till it became nicely tolerable. If it works, that's right about where I stop adjusting things. The crazy part is, that very Weber 32/36 progressive was swapped directly into my EJ22 Soob and it runs fine without ever needing a jet change. I surmise neither was / is mega optimized but I can't argue with the easy starts, smooth acceleration and 39 mph US either.

...easy starts, smooth acceleration and 39mpg?

 

   God always did favor the Canadians...just as I've suspected.

Nothing to do with it, Carl.

They have bigger gallons.

David's mileage wasn't calculated on Imperial gallons.

I did bugger that number up, Guys. I said 39 mph US and meant to say 39 mpg ( US gallons) but I forgot to add that was highway traveling from Canada to Key West and up to Carlisle last year. For the record, the US gallon is 83.26% the size of a Canadian gallon. Either way, the speedster's fuel consumption it's a shytload better than my Dodge Ram Hemi that I use daily for work.

I'm not surprised that a modern electronically controlled engine like David's subi pushing such a light car can achieve such good mileage.  One of the advantages of the latest technology.

Remember that throttle cable you fixed for me, Lane ? That was attached to a dirty old Weber 32/36 progressive carb mid mounted on a chewed out / welded up stock EFI manifold. The only thing modern electronically controlled item is the ignition and I doubt it's maximized in it's tweak either. I simply picked a stock, right off the shelf ignition table and plunked it into the Megajolt system. No further adjustments. My approach to the conversion was somewhat clumsy in that I just didn't know any better and didn't dump a pile of cash into it because I wasn't sure it would work well. Surprise, surprise. I think we can conclude the Soob is a very forgiving engine and quite adaptable to a variety of approaches. The only previous experience with a Soob was an EA81 I put in my airplane back in 1998. The carb on it interestingly enough was a Holley 5200 straight out of some old Chevette with a couple of jet changes. My current Weber is almost a clone of that one. Deja quoi ?

Oops.  Yeah, now I remember.  Senior moment.

I am running a 009,and if you take a methodic approach to it,you can get incredible results. My technique was to use my knowledge (I am an experienced EFI tuner on high HP turbo street cars)about afr & timing adance and used it on this archaic speedster of mine.

 1. I used 4 EMPI snails to perfectly balance the carbs and synch them as well.Also I got the heim joints onthe 44idf linkages all perfectly aligned,etc.

 2. I welded a 02 bung in the collector so I could use a AEM wideband afr gauge to adjust the jetting.

 3.I only tuned when engine has reached full temperaure.

 4.Knowing that the 009 distributor makes peak advance at 3200rpms,this was way too high for a motor with a 6K rpm limit and mostly being shifted at 4-5K during normal driving. This allows a very small window of full advance. These cars are very light and even when under load the motor is  not stressed,and can run more timing advance than the normal 009 curve. I "stretched" the spring in the 009 advance mechanism which brought full advance of 30 deg. in at 1800-2K rpm,which gave me a much broader tq. band and much snappier off idle response,it really woke the car up. Also at cruise,the car is running full advance which helps with gas mileage and light throttle response/transition as well.

 I do not recommend 034 for dual Weber since the vacuum signal is not strong enough IMO from only one barrel to operate the vac. advance properly on IDF's.

 After setting everything up,the last piece of the puzzle was getting the accel.pump set up and now my car has.......NO BULLSHIT,  EFI drivability,it literally drives PERFECT,I mean,no bogging/sputtering/hesitation/factory like drivability. It takes time and effort toget there,but I even surprised myself with how well you can get a total aftermarket/performance ACVW to drive this well.

 

 The icing in the cake is the new Malpassi regulator that I have just installed,it made great even better. 

Great post! The SVDA I got was from Aircooled.net and they Cé tweaked and optimized for te application; in my case dual Dell 40's. works like a top with the vacuum signal from the left carb.

I meant "come"; stupid spell checker in my phone.