009 flat spot, vacuum needs for SVDA dizzy

I've still got that bit of a flat spot with the new engine and the 009 dizzy it came with. The progressive Weber doesn't have a vac port but I did notice one on the left side of the intake manifold. Reseach shows a SVDA dizzy needs at least 8" of vac, so I rigged up a gauge to the manifold port and at 1,000 rpm I get 7 to 10" but the vac needle bounces back and forth quite a bit. Does anyone know if that vac port would support the needs of the SVDA ? Does vac have to come from a carb...not a manifold ? Is it smoother there ? Other research showed that tweaking the accelerator pump might help but mine appears non adjustable, just a cam pushing the lever. I can borrow my SVDA dizzy back from the lad that bought the engine and try it out, but thought I'd ask here first. Thanks.

You need a "timed" vacuum port that takes it signal from the lower venturi, the manifold vacuum won't work at all.

The Weber progressive has a vacuum port beneath the choke more or less, but it's too restricted to be of much use as-is; you can use a series of reams to open it up but you gotta know what your doing.

The distributor that was used in the fuel injected Type II has a better advance curve than the 009, much more like that of the 010, you might want to try that. They have what seems like a vacuum canister on the side, it's not used as an advance, but rather a retard. The distributor itself is a full mechanical advance version. Just remove the canister or ignore it. I'm playing around this this distributor right now, hoping for some great results.

Luck,

TC

The SVDA is designed for stock single or will also work with twin Solexes, don't know about other carbs. If I recall, the SVDA doesn't need much vac signal at all to activate the advance mechanism. The 009 dizzy SUCKS!

Having said that, a lot of time what is mistaken as a timing issue is really a fuel issue. Either too rich at idle, or WAY too much volume on the accelerator pump will cause an off-idle stumble. Backing off the accel pump pushrod can totally eliminate the stumble, but it takes time and patience...........

I removed my 009 and replaced it with a 019. flat spot gone. the aftermarket 009 had lots of slop in the shaft. If you can find a german 009 you are better off.

Or get the distributor that Wild Bill uses - it's a Mallory, I think, but it eliminated his flat spot.

Gordon,

It that the old version, or the brandie new one?

I picked up a beautiful NOS 'Ol Skool Mallory dual point and an extra NOS tune up kit from one of the VolksRodders and have been dying to try it out. I know the dual point Malloy's from running them in the TR8s, but never had one in a VW engine before.

Just wonderin' . . . if it IS the older style, how do they run?

Wild Bill...could you chime in here and tell what you know about the Mallory ? Did you go electronic as well? How tricky was it to set up the correct advance curve etc. ? What dizzy did you replace and could you confirm no hesitation, better low end power and any mpg change ? Thanks.

Well, colour me stupid if you need to ! Patience has never been a strong suit with me. I was trolling the net to learn more about vacuum ports on progressive Webers and I found an old post from some other net wherein a lad enquired about Weber vacuum ports. He got a reply confirming what he saw was indeed a vacuum port. I checked my Weber again ( it's hard to see back under there ) and I've got one too. I hooked up a gauge to it and, what I think is correct for a SVDA dizzy, it reads zero at idle and zips up to 10" when the throttle is blipped. Nice and steady, no erratic behaviour. Now, before I run out and get a new SVDA, could anyone please confirm to this idiot that what I see is what I need ? Thanks.

Just to finish off the thread in case someone else comes up the same combo of 009 dizzy and a Weber progressive the anwswer is yes, it can be made to work. On the advice of the tech lads at CIP1 I started messing with the jets, one step at a time and got the flat spot to go away. The jet numbers are high on the scale according to what Aircooled.net recommends but it cured the flat spot. The 009 is set at 10 deg BTDC idle and goes up to 32 at anything higher than 2600 rpm. Combined city and highway driving shows 26 mpg where I got 35 mpg last year with the stock 1600 highway only.

What are the numbers? What size jets worked the best, good info to share for sure.

Glad that it worked out well ! ! !

TC

Oh . . . since you're running the 009, did you remember to plug the open vacuum port on the back of the Weber? Even a small opening/port needs to be closed off if it's not being utilized.

32 Degree's is way too much advance. You're going to detonate and cause some real mechanical issues.

NEVER set a 009 distributor at idle. Increase your engine speed to around 3000 RPM's and then set the total advance to 28 degree's before top dead center. This WILL save your engine from exploding

Yes, the vac port is plugged on the Weber. The idle primrary jet is a 65 and the secondary is a 75. Originally they were 65 and 55 repectivley. I relied on Aircooled.nets info here: http://www.vw-resource.com/009_dizzy.html#timing where they said it could be set at 30-32 degress which might yeild 5-10 degrees at idle so yes, I'm on the top end of that scale. I'll drop it down to 28 and see how things run. Anyone else have any input/experience to share about advance at the high end ?

Here's the deal on advance. If you're running 93+ octane, (not available in most states) You may be able to get away with 32 degree's especially if you live in a constantly cool climatic zone.
If you're using 87 to 91 octane and/or your climate is warm then 32 degree's is way too much.
What happens in the combustion chamber is this: A hot spot develops on the top of your piston or cyl. head, it gets so hot that it prematurely ignites the fuel/air mixture and causes a rather sharp metalic sound much like a hammer hitting metal or a series of rattling sounds. This is called detonation. I've rebuilt many an engine that suffered from detonation and it's not pretty.

To be on the safe side, I ALWAYS set my customers advance at 28 degree's @ 3,000 RPM's and so far, no detonation. You'll feel more power at 32 but ultimately it will cause severe damage to your engine.

David-I read your posted link. Here's another link from the same site:
http://www.vw-resource.com/hestate4.html#009

Thanks for the input, Lads. The long and short of it is that I've read that anything up to 32 deg for the 009 can be used. More recommend 28 to 30 so now I've settled on 28 at the top and it results in 7-8 at the bottom. I couldn't hear any ping at 32 but with the top up everything is noisy. It pulls almost as well at 28 as 31-32 in the range that I want but the flat spot is a bit more pronounced and I'll just deal with it. We've got a 4100 + mile trip on the horizon and I don't want to bust anything on the road.I might
frig a bit with the main jets between now and May 1st.

David;
You obviously installed a heat riser manifold , or your carb would freeze .
But is it supplying enough heat while your DRIVING ?
Did you insulate the runners ?

I didn't insulate the heat risers but have felt the manifold underneath the carb when all is warmed up and it feels warm to the touch when driving in -6 deg C. My manifold is not the best type either, the better ones have the heated channel right up under the carb and with mine (SCAT) the heat gets to the bottom of the manifold and that's it. Further, I understand some manifolds are designed to have full flow heat from the risers whereby heat comes up one side and heats the manifold as it goes by and out the other side.