Timing Theory Question

[MeMatt]

Evening all, 
Classroom question. Just for my curiosity. 

Does not relate to a particular engine or car, but if it helps lets use my engine. 
1916cc, 8.7:1 CR, W100 mild cam, 009 dizzy, electronic ignition, twin empi kadron style carbs. 
My mind has been working overtime trying to figure out something. 
I have static timing at 8degrees. Engine runs. 
Its going to local mechanic so he can set 32degrees at 3,000rpm. 
Then I can get a proper tune in the coming weeks… 

Question, is there a calculation for static to dynamic timing conversion?
ie; 32 @3000 = 18 @static. (Just random figures)

Cant be a straight forward relationship…. can it?
I think that engine build specs and performance must affect timing adjustment capabilities. 

I have googled but getting confused. 

Thoughts,

[Barry]

There are others that know more but here is my 2c

7.5* - 8* static is a good base line.
There is no "magic" formulae to convert to maximum.
It depends on your distributor 

If you set your static you can set your maximum.
You just need a (decent) strobe light

[MeMatt]

Thanks Barry,
Just wondering if timing increases at a linear rate from static to 3000 rpm. 
Or is it a percentage rated increase, or purely based on the build of the dizzy internals (internal cam and throw) 12@1200, 22@2100, 30@3000, 30@3500…. 

No real reason for me asking other than my mind has been thinking about it because of engine work thats been going on.

[Mordred]

Here's another angle.

The 009 you are using is not a good choice for a bus. 2nd if it is a new copy of the 009 there is a high probability that it doesn't have the right curve in advance as the quality is very variable.   You wont have to do much research to find you will be far better off with a vacuum advance distributor. If you cant find an original in good condition (https://oldvolkshome.wetwesties.org/ignition.html for a list of the original numbers) then a programable electronic one may be the best option. The 123Tune+ can be programmed with many different curves and you can adjust them as well.

It has been noted in many forums that the 009 was designed for static engines such as air compressors and other industrial engines that run at one governed speed. The 009 was always noted to cause flat spots on acceleration and that is because it doesn't start advancing until the engine is off idle, and at cruise speed the advance isn't adjusted for load so you will always be over or under advanced except at full throttle.  This causes heating and poor combustion and in some cases detonation, all of which will affect your engine. The bug racers used them as they were much cheaper than the vacuum advance dizzys and since they were running flat out a lot of the time they didn't need to be worried about partial throttle opening and the flat spot that most people find when running 009's.

VW never fitted a 009 to a vehicle engine from the factory, and they cut every corner possible to keep the cost to a minimum. Why is that?  Because they wanted a reliable engine that didnt need to come back for warranty work.

You will have a lot less trouble than setting up a 009 and getting a well running engine.

Adrian

[Tintop]

plus 1 on the 009 comments

[grumble]

Here's another angle.

The 009 you are using is not a good choice for a bus. 2nd if it is a new copy of the 009 there is a high probability that it doesn't have the right curve in advance as the quality is very variable.   You wont have to do much research to find you will be far better off with a vacuum advance distributor. If you cant find an original in good condition (https://oldvolkshome.wetwesties.org/ignition.html for a list of the original numbers) then a programable electronic one may be the best option. The 123Tune+ can be programmed with many different curves and you can adjust them as well.

It has been noted in many forums that the 009 was designed for static engines such as air compressors and other industrial engines that run at one governed speed. The 009 was always noted to cause flat spots on acceleration and that is because it doesn't start advancing until the engine is off idle, and at cruise speed the advance isn't adjusted for load so you will always be over or under advanced except at full throttle.  This causes heating and poor combustion and in some cases detonation, all of which will affect your engine. The bug racers used them as they were much cheaper than the vacuum advance dizzys and since they were running flat out a lot of the time they didn't need to be worried about partial throttle opening and the flat spot that most people find when running 009's.

VW never fitted a 009 to a vehicle engine from the factory, and they cut every corner possible to keep the cost to a minimum. Why is that?  Because they wanted a reliable engine that didnt need to come back for warranty work.

You will have a lot less trouble than setting up a 009 and getting a well running engine.

Adrian

Well written Adrian there have been many engines destroyed with these distributors and people trying to get better performance out of their vehicles.
Cheers
Les

[rstucke]

Well written Adrian there have been many engines destroyed with these distributors and people trying to get better performance out of their vehicles.
Cheers
Les

009 is a good cheap distributor to have in your emergency pack to get you home when your original one dies
I have one in my pack and have set it up as a drop in (hold down clamp attached) if my 123 distributor ever lets me down

[Mordred]

Agreed, Much better than nothing when you have an electronic set of points, as if they die that's it.  I have my original vac dizzy in the back with points and set to my engine so it it just swap it out and go.  

I do like the electronic ones for the low maintenance and with programmable one's ease of changing settings and curves if required and on some the monitoring functions, but for getting home ability give me the points any day.

Adrian

[1500king]

Evening all, 
Classroom question. Just for my curiosity. 

Does not relate to a particular engine or car, but if it helps lets use my engine. 
1916cc, 8.7:1 CR, W100 mild cam, 009 dizzy, electronic ignition, twin empi kadron style carbs. 
My mind has been working overtime trying to figure out something. 
I have static timing at 8degrees. Engine runs. 
Its going to local mechanic so he can set 32degrees at 3,000rpm. 
Then I can get a proper tune in the coming weeks… 

Question, is there a calculation for static to dynamic timing conversion?
ie; 32 @3000 = 18 @static. (Just random figures)

Cant be a straight forward relationship…. can it?
I think that engine build specs and performance must affect timing adjustment capabilities. 

I have googled but getting confused. 

Thoughts,

Most 009's have 22-25 degrees of advance, finishing at ~3000rpm, starting ~400-600rpm

Then there's the build quality variation...could be anything.

[1500king]

Evening all, 
Classroom question. Just for my curiosity. 

Does not relate to a particular engine or car, but if it helps lets use my engine. 
1916cc, 8.7:1 CR, W100 mild cam, 009 dizzy, electronic ignition, twin empi kadron style carbs. 
My mind has been working overtime trying to figure out something. 
I have static timing at 8degrees. Engine runs. 
Its going to local mechanic so he can set 32degrees at 3,000rpm. 
Then I can get a proper tune in the coming weeks… 

Question, is there a calculation for static to dynamic timing conversion?
ie; 32 @3000 = 18 @static. (Just random figures)

Cant be a straight forward relationship…. can it?
I think that engine build specs and performance must affect timing adjustment capabilities. 

I have googled but getting confused. 

Thoughts,

Great starting point on that motor is to try  the 043905205B late bus 1600 mechanical curve with 7.5 degrees advance static/initial, with the 72/73 type 3 vacuum advance curve, and modify the Kadrons for ported vacuum advance.

It will be a different animal after that.

You may even need to lean up the carbs where they've been tuned rich to get over the 009 flat spots.

IMHO, comps are a bit high, low 8's max for an engle 100. Any higher is not better, especially for a bus.