009 question....

[Tofufi]

Just to add, it should probably be timed at 7.5 degrees BTDC, rather than 10

I doubt in practise it will make a significant difference, but 7.5 degrees was the factory idle point for the normal SVDA distributors. 5 degrees ATDC was for the DVDAs (which never worked well even from the factory).

Having it advanced too much will make it run hotter, but I doubt the 2.5 degrees will make much odds.

Glad you're happy with the result - I've it makes a huge difference in a heavy bus, more so than a bug.

I *think* the 009 gives the impression of more 'grunt' because when it finally gets over the flat spot it has a lot of fuel going through it, giving you a sudden push in the back - whereas the SVDA gives a smoother application of power, so you don't feel the 'push' as much.

 

[noddy]

Just to clarify the last point some SVA dizzies have 32 degrees total advance, models like 113.905.205.T and 205.AA and need to be timed at TDC. If you can get your self a strobe with a advance function gunson do one for about £40, also to get your revs an inpulse tachometer is the best way to go, measures the electrical discharges from the coil to dizzy lead, bought at pet-2000 of ebay made by these people cost £12 geat bit of kit http://www.oppama.co.jp/eng/gaiyo.html" onclick="window.open(this.href);return false;

 

[Tofufi]

Just to clarify the last point some SVA dizzies have 32 degrees total advance, models like 113.905.205.T and 205.AA and need to be timed at TDC. If you can get your self a strobe with a advance function gunson do one for about £40, also to get your revs an inpulse tachometer is the best way to go, measures the electrical discharges from the coil to dizzy lead, bought at pet-2000 of ebay made by these people cost £12 geat bit of kit http://www.oppama.co.jp/eng/gaiyo.html" onclick="window.open(this.href);return false;

The SVA distributors above were for single port engines, and have the wrong advance curve for a twinport engine (with stock carbs) anyway

If you have a correct Bosch/VW SVDA it should always be timed at 7.5 degrees BTDC unless anyone knows otherwise?

I don't consider the advance on the timing gun to be necessary to be honest, I've just got a cheapy one and it works just fine

 

[noddy]

Although the 205 t and AA were intended for single ports engines they can still be fitted to later type 1 engines with the universal case. The only major difference between a single port and twin port long block is the heads, and the later universal case has the duel oil relief valves.

So you will still need to be careful if you have or are fitting an SVA dizzy.
As I said earlier the 205's have 32 degrees total advance, so if you time at 7.5 degrees before TCD on one of these you will end up with 39.5 degrees total advance and as a result a cooked engine.
This is why it is best to time using a strobe with an advance function if you are unsure of the total advance an SVAD is capable of.

 

[Tofufi]

Although the 205 t and AA were intended for single ports engines they can still be fitted to later type 1 engines with the universal case. The only major difference between a single port and twin port long block is the heads, and the later universal case has the duel oil relief valves.

So you will still need to be careful if you have or are fitting an SVA dizzy.
As I said earlier the 205's have 32 degrees total advance, so if you time at 7.5 degrees before TCD on one of these you will end up with 39.5 degrees total advance and as a result a cooked engine.
This is why it is best to time using a strobe with an advance function if you are unsure of the total advance an SVAD is capable of.

Yes, but the single port engines have different carbs which produce a different vac signal

Hence the SVA distributors not being suitable for most twinport engines. The SVA is a different distributor to the SVDA anyway, and not easy to confuse between the two.

The strobe doesn't need an advance function to be able to check the total advance

 

[noddy]

I dont agree.

To be able to check what vacuum signal a carb is pulling and how SVA distributor is responding you do need a strobe with an advance function.

As most engines are a hybrid of carbs and distributors i.e. no longer stock there is no certainty that you are not exceeding total advance unless it is timed dynamically.

I have had SVA distributors that have had between 30 and 34 degrees total advance and without a strobe with advance there is now way of checking how far the advance is.
Also vac advance distributors have two places in the advance curve that if you are really being pedantic can be checked to make sure the distributor is working within parameters, but you need a vacuum gauge, a tachometer and strobe with an advance function.

I would recommend dynamic timing over static any day.

 

[Tofufi]

I'm not arguing dynamic Vs static. I time my engines dynamically using a strobe gun.

My strobe gun doesn't have an advance function on it though - I have a degrees pulley on my beetle, and I have marked 32 degrees BTDC on my van pulley. This allows me to check the total advance without the use of a strobe with the fancy advance function

Are you talking about SVA and SVDA distributors here, or just the SVA ones?

 

[noddy]

Hi Tofufi

Just SVA, a lot of engines Ive worked on don't have the timing scale, if they do then yes your right about not needing a timing gun with advance.

I seen some really bad combination of carbs and distributors. At vanfest I tried to help a guy who describe a running problem he had on the motorway coming to vanfest, it sounded like classic overheating. Turns out someone had fitted a webber carb for him and it was pulling the SVA distributor to full advance at tick over.

It sound like either fit a timing scale or get a strobe with advance.

Ian

 

[Tofufi]

Hi Tofufi

Just SVA, a lot of engines Ive worked on don't have the timing scale, if they do then yes your right about not needing a timing gun with advance.

I seen some really bad combination of carbs and distributors. At vanfest I tried to help a guy who describe a running problem he had on the motorway coming to vanfest, it sounded like classic overheating. Turns out someone had fitted a webber carb for him and it was pulling the SVA distributor to full advance at tick over.

It sound like either fit a timing scale or get a strobe with advance.

Ian

Fair enough

I know what ya mean about the bad combination - sounds like the weber had the port in the wrong place / giving the wrong type of vacuum. I wouldn't touch a single 32/36 with a bargepole though, although I'd like to see them made into twin carbs...

 

[Benyon]

Hmmm, so SVA, SVDA but no 009.

Can anyone give me a guide as to what I need to get then, part nos useful, to get back to the stock SVDA. I have a 1600 with twin Weber 34ICTs, current 009 dizzy has Pertronix ignitor module fitted will I be able to keep this?

I know there is another thread Johnny was involved in dicussing drilling tapping off a vaccuum source from twin carbs but I got lost following it, anyone know if the Weber ICTs have a vaccuum post already drilled?

 

[matt-me]

Benyon, check out page 3 of this thread. This is only my opinion

 

[Benyon]

Benyon, check out page 3 of this thread. This is only my opinion

Cheers Matt-me, I have already read your post but obviously not well enough. So ICTs have a vaccuum port ready drilled - great! 8)

 

[Stirlingmoz]

I've been reading (and re-reading) this thread with interest as I currently have a Bocar + 009 setup.

There is a flat spot off idle which detracts from the driving pleasure and requires a good deal of revving for a smooth takeoff.

I was hoping to solve the problem by returning to a standard setup and am reconditioning a Solex PICT 3 34 carb.

BUT

The distributor thing...What distributor do I need SVA or SVDA ?.

I have a dual port engine.

Can you tell the difference by looking and if so what are the differences ?

Starting to understand now :?

Stirlingmoz

 

[Tofufi]

You need a SVDA. Part number 043 905 205L or just 043 905 205 is correct for a bus.

The SVDA has a fatter, smaller diameter vacuum can compared to the SVA.

SVDA...

SVA..