More irritating distributor questions ...

[Derek May]

I don't want to start a debate on this topic around the virtues, drawback of the Bosch 009, but I would like some information from anyone in the know.

I drive a 75 Van with a 76 engine. Service guy tracked down bucking problem (engine would cut out) to bad dizzy. Stock dizzy was Bosch 231 168 005. I think that's pretty typical. He says "I'll just pop in an 009. I said, "I hear that's not good in a Van". He pokes around, has nothing else, charges me $35 for the used 009 (aside from labour) and I drive off.

I nose up to end of driveway, head out into traffic, pedalling like I always do, and the thing dies. Try again, dies again. Rev the engine, it goes. Drive around, old girl Gretchin runs terribly at low rpm unless the pedals mashed. I'm driving full on, full off most of the time. Much finesse lost, I'm quite sure I can feel the difference in drivability, and I don't much like it. I'm going to hit the freeway and some hills when I get a chance, maybe there's benefits I haven't felt yet.

Someone posted this in an article at www.type2.com:

"Porsche didn't bother with a vacuum advance. The idea was that you would *always* be at wide open throttle. If not, why did you buy this car??? So the vacuum advance would never come in to play anyway. Ditto for the early transporter. Look at an early splitty. The gas pedal is bent to match the contour of the floor where some cat spent all his time trying to push it into the pavement. So for some engines, VW (Bosch) made mechanical advance distributors.

"Ok" for full power settings, but at lower throttle settings, engines can use some more advance. Reason? The flame front moves slower as the mixture in the cylinder gets less dense. So we can get started earlier and catch the peak pressure just where we want it, even at low outputs. This helps the engine temperature, as the mixture is not burning late, helps the power, as the peak pressure is at the right place in the stroke, and helps the fuel economy as the fuel is being used effectively."

"The vacuum adds advance at anything less than about WOT. It uses what is called "Ported" vacuum. It's blocked off at an idle, but as soon as the thottle opens, it gets full manifold vacuum. There is a built in lag in the vacuum advance that allowed you to change throttle settings quickly and snap back to where you were and the advance would not have a chance to change (much). This makes the engine seem "smoother". You are unable to "suprise" the thing with quick throttle motions. This is what John Muir was saying about having to keep your foot on the gas with "elan"."

This fits with what I'm experiencing. Engine only drives decently at WOT (wide open throttle).


Options seem to be:
1) dig up old 005 in wrecking yard, in whatever shape it may be in. If my 26 year old dizzy is dead, why would other 26 year old dizzy's have much more life.
2) live with the 009
3) try an 050.
4) try the SDVA
John Connolley's aircooled.net sells all three)

performance characteristics of the 005 stock dizzy: from http://www.oldvolkshome.com/ignition.htm

Timing Set At:: 7.5deg BTDC @ 850-950 rpm (Man Trans), 900-1000 rpm (Auto Trans) w/strobe, vacumm hose connected
Advance/Retard Range: Vacuum: 8.5-11deg Adv @ 7.9 In. Hg; Centrifugal: 8-13deg @ 1600 rpm, 20.5-24.5 @ 3400 rpm

CB Peformance says this about the 009:

"The 009 is the economical replacement unit designed for those requiring a mechanical advance distributor. Easy to adjust points are mounted on a solid grounded breaker plate to help eliminate point wobble and chatter at normal speeds. Easy to install, replaces original with hand tools. Fits all 6 or 12 volt 1955 to 1974 Type 1, 2, & 3 VW engines. Excluding fuel injection models."

Great -- I'm running 2.0FI type 4 with an 009.

CB performance says this about the 050:

"The best performance distributor you can run. No other VW distributor will perform with the 050. The points are mounted on a solid breaker plate to eliminate point wobble, bounce, and flutter. The 050 will wind and fire evenly to over 8,000 RPM. It's genuine Bosch and it is designed for performance. The cylinders fire evenly. You can set your timing at TDC and the 050 will advance to 27 degrees without fudging the timing at idle speeds. And yes, you can run the 050 on otherwise stock engines. Independent tests have shown horsepower increases and a big jump in fuel economy by installing an 050. They can be used on any 4 cylinder, air cooled VW, Porsche, or water cooled Vanagons."

www.aircooled.net says this about the 009 and 050:

"[009] Centrifugal advance only. Fits everything EXCEPT 1968 and newer fuel injected Type 3's. We recommend the 050 for Type 4 engines, and the 009 for upright and type 3 engines. NOT recommended for engines with stock dual port carburetor, 34 PICT (instead see SVDA Distributor)."
www.aircooled.net says this about the SVDA:

"This is our recommended unit for Dual Port engines when using a 34 PICT carburetor or the Weber progressive. Comes with points and condensor, but NOT a cap or rotor!
These distributors use the same cap and rotor as the 009."

I found this in the library at www.type2.com regarding the 050:

"Its advance characteristics are similar to the Brazilian manufactured "009" (there are some that were made in Germany as well, and they say "Germany" on the bottom of the can, and have different advance characteristics, too). The "050" has a smoother advance curve (flatter line on a graph of rpm/degrees advance). The advance kicks in at around a hundred RPM lower than the "009," making it more suitable for use in a van. The "050" also advances to a greater degree, around 26 degrees at ~3100 rpm, while the "009" poops out at ~2650 RPM with a total advance of about 21 degrees. These numbers are approximate, and will vary between distributors and reference literature.

"I find the "050" is more driveable than the "009" Brazilian unit that I keep as a backup. Neither is as driveable as the vacuum unit, but since I'm running dual Dellortos I can't drop in the stock vacuum unit for a direct comparison."


From this, they appear to recommend the centrigal advance 050 for the FI type 4 engine.

Jake Raby at aircooled technologies uses the SDVA (he says he makes some modifications but doesn't say what and won't sell the modified dizzy .

So, here's my queries:

Recommended replacement dizzy -- 009, 050 or SVDA?

What are the timing and advance characteristics of the 009? 050? SVDA?

I don't know if any of this is reliable, but from the stuff I have I can list the following comparisons:


Centrifigal Advance:
stock 005: 8-13 @ 1600 rpm, 20-24.5 @3400 rpm
009: ? 21 @ 2650 rpm
050: ? 26-27 @ 3100 rpm
SVDA: ? ?

Can anyone fill in the blanks? How do the Vaccuum characteristics of the SVDA compare to the stock 005?

Thanks in advance.

[Bob Ingman]

Darek there has been a real good thread about this on type 4 forum recently. Those involved include Shad Laws who wrote the three part series on distributors this year in VWT magazine. Also involved was Ray Greenwood and I know you are familiar with his knowlege of VWs F.I. system and the Bosch electronic
components that comprise it.
I think the thread was called " is the 50 better than the 09" or vise versa. Should be on the first page as it`s very recent, and very in depth. Good Luck. Bob

[This message has been edited by Bob Ingman (edited 10-18-2001).]

[ray greenwood]

Derek, It is incorrect to state that vacume advance does not add anything at WOT. This depends upon, from point in the manifold you are obtaining the vacume source. It is true on most engines that when you dump the throttle wide open, that for a moment, the pressure drops to almost normal atmosphere...but it climbs very quickly spending upon the nature of your engines breathing characteristics and how quickly the rpm climbs. This is why having a combination of vacume and centrifugal advance isvery important. The centrifugal acts as the sustainer for that particular "moment". On my 412, before I properly "tuned" the weights and springs on the the centrifugal advance, there was about a 5 dgree lag in adavance when watching with a timing light...when revving from say...1500 to about 35oo rpm. In other words, the vacume was keeping me at about 28 degrees of advance...until I hit the throttle wide open. At that moment it dropped to about 25...and then in a split second...at WOT...it pumped up to about 40 degrees advance. I wired the advance weights down...then tried it again...for the same effect...to ascertain wether itwas the vacume or the centrifugal which was giving me the extended advance. It was the vacume. Vacume loss...at least on a type 4's with standard throttle bodies is only momentary at WOT. It almost instantaneously re-establishes even at WOT...to give large advance. If course, from engine to engine ...and manifold to manifold...and depending upon cam, this can vary. But you will always be able to find, somewhere along the manifold length a vacume source position that does this. By the way, the 914 w/ FI has always used vacume advance. The 1.7 and some 2.0 had an adjustable stroke length on the dual unit...to keep the vacume from overadvancing at wide open throttle. I adjusted mine back to 36 degrees. Ray

[Derek May]

Thanks Ray. My information is second hand, I've tried to set out the source, I'm not vouching for its accuracy -- and appreciate your comments.

I've now driven the 009 for a day and a half, and have adjusted. I can drive the van fine, it took some adjustments in driving style which may be interesting to some who read this.

First, I now need to rev the engine and slip the clutch starting from stationary more to a greater degree than before.

I run at higher rpm, lower gear. At a speed where I used to run comfortably in 4th, I'm using 3rd to keep engine running well.

I downshift a lot more. With stock cam, if I was in 4th, and had to slow, then apply throttle again -- no problem, it motored smoothly back up to speed. Now, I have to shift into 3rd if I loose to much speed, and shift back into 4th when the rev's get up.

I've adjusted to the new driving style fairly easily, and it wouldn't be too hard to get used to it. One might even think that's how a Van runs, if one didn't know better. Feels more like a carbed bug than a FI Van, actually.

Thinking about the Mallory sold by John at aircooled.net. If I end up putting non-stock performance FI in it one day (in my dreams) or even dual dells, I can retune the thing and still use it. Better be good for the price.

I've a good van, I don't like the idea of swapping my worn out parts for some other nearly worn out parts if it can be avoided.

I can't find any source for new/rebuilt stock dizzies. Would love for someone to correct me and point me in the right direction.

[Pillow]

Hey Derek,

All that revving to get into first is terrible for your clutch.

I think the SVDA Aircooled.net sells is just a refurbished used dizzy. If you special order one I am sure they can tune it to whatever application you need (just one spring controlling vacuum advance - mechanical advance is fixed).

If you have the correct vacuum canister and spring for the dizzy just replace the ordinary stuff and you have a fine dizzy for about $30... Provided the there is no sideways shaft play.

Good Luck,


------------------
Adrian Pillow
'66 VW Westfalia - "Biscuit"
'79 Porsche 911 SC - "Cochise"

[Derek May]

The problem is the shaft.

I don't like all that reving either, although its not that much -- its probably acceptable to most people, I'm describing it as an increase over what was necessary before. Some people like the 009 ??? I'm relating my experience as a relucant convertee.

I'm probably going to dig up a used stock dizzy for now, perhaps consider the tunable mallory at aircooled.net.

[TomB]

Well, if you don't like used : I recently got a new VW - Bosch (Mexico) 043 905 205 ZB distributor (SVDA) from btlmex.com. Functionally seems very close to the SVDA rebuilt I got from aircooled.net - but cheaper. True, casting finish and details don't look like "NOS" but functionally works well, and for me that's worth more than pedigree.

[Derek May]

TomB's post took me to btlmex.com to review their offering of parts. I noticed they sold a vacuum unit, descibed as for the ".009", although the distributor described as an .009 actually is listed in their parts listing as an: 043905205ZB

Can I pull the vaccuum unit off my 205P and stick it onto an 050? Anyone tried this, know if its possible, if it works? If it is a good idea?

I don't have an 050, but I understand the advance curve (centrigal) is closer to the curve of the 205 OEM than an 009, which comes on too hard and fast for my liking.


Thanks.

[Derek May]

I sent an email to btlmex.com asking a few questions about that distributor -- and have no answer. I'm not impressed so far.