2.1 Distributer

[Pickles]

I fitted a 1.9 distributer to my 2.1 due to electrical failure of the 2.1 unit
I thought they were the same.
I have since read Simons excellent details on Brickyard
and found that the advance is different

2.1

ignition timing 10°±1° BTDC @ 800RPM without vacuum see note.
Ignition advance checks 0°-2° @ 1050RPM w/o vacuum and basic timing
2°-6° @ 1300RPM w/o vacuum and basic timing
12°-16° @2400RPM w/o vacuum and basic timing
vacuum advance range 12°-16° engine degrees (9-11)
idle speed 800±50 RPM

1.9
ignition timing 5°±1° BTDC without vacuum see note at bottom of page
ignition advance checks 0°-2° @ 1500RPM w/o vacuum and basic timing (0-1 @1160)
10°-14° @ 2400RPM w/o vacuum and basic timing (13-17 @2400)
24°-28° @4200RPM w/o vacuum and basic timing (24-28 @4200)
vacuum advance range 12°-16° engine degrees
idle speed 900±50 RPM see note at bottom of page


My question is what are the physical differences
I assume that the weights are different and that the electrics are the same. Is the vacumn part the same. I want to fit the 1.9 electrics into the
2.1 body.

The advance figures from Simon are they the total advance or do I ad 10deg to this. I will check total advance with a strobe.

[Fritz]

I suppose the logical answer to your question would be : 'IF' the part number was identical for the 1.9 and the 2.1, it may be safe to assume they are identical in every way,,,,,,,,,,,,,,,,,,,,BUT , if it was that simple any silly basrtad would be a motor mechanic,,,,,

Its not about the mechanics of the dizzy you have to worry about , it will be the dynamic timing control and the advance curve which will be the differences in the 2 physical control systems.

In simple terms a lot of the 2.1 system is regulated by the ECU, and that is the difference when compared to any 1.9 which is only one step away from contact breaker points, from the earlier piece of shyte they used to make.

Regards

Fritz,,,,,,,,

PS , this may be the only answer you are likely to get on this subject,,,,,,

[HarryMann]

From Wiki link here...
http://wiki.80-90.co.uk/index.php/Petro ... nce_curves

[Pickles]

Thanks for the graph HarryMan
I assume the DJ 10 deg line keeps going up to about 40 deg

I have swapped the good electrics in to the 2.1 distributer body and fitted it to my 2.1.

My question is timing what is the total advance (max)

I timed it with both vacumn lines off and plugged. and the stabilser plugs connected together. I timed it at 14 deg (for LPG) as advised by toomanytoys. I checked full advance and it was 40 deg is this too much.(appears ok from graph)

From Brickyard

ignition timing 10°±1° BTDC @ 800RPM without vacuum see note.
Ignition advance checks 0°-2° @ 1050RPM w/o vacuum and basic timing
2°-6° @ 1300RPM w/o vacuum and basic timing
12°-16° @2400RPM w/o vacuum and basic timing
vacuum advance range 12°-16° engine degrees (9-11)


As the details above is it 10 deg + 16 deg vacumn + 16 deg mechanical

Therefore 42 deg

Am I correct

[HarryMann]

I assume the DJ 10 deg line keeps going up to about 40 deg

Well, I'd say no. You generally find that centr. advance stops and levels off at max torque or thereabouts.
And 25~35 degrees of total advance is what might be expected, so the figures do seem to fit (26 degrees)... and the larger or longer stroke the engine, perhaps the earlier the centr. adv. levels out.

Once you think it's all setup OK, always worth swinging it either way 2 or 3 degrees, for a week at a time if its a daily driver, as a quick blast up the road doesn't always reveal a firm conclusion. Then swing it right across centre to 2 degrees the other way, and that'll help prove the case for the prosecution - before you're half way to work you should know what has changed and whether its better, but don't switch it back straight away unless it's obviously pinking badly or feels really sluggish. I'd often retard it from the set position first, and sometimes a lot more than 2 degrees! Many a shock result been had there, and left in that position for ever more

That's assuming the injection system is about right and the plugs can fire the mixture, even when weak. The feeling that it will keep roling along happily on a light throttle with more to come and yet tolerates lugging low down without snatching or pinking badly is what I think you're after. A good 1.9DG has a halovely bit where that sort of ease of driving is concerned, so a 2.1 should too, but there's much more that can mess things up it seems.

Hope that helps, I'd use use Simon's figures to check and set it all up if you can.

[Pickles]

Always run on LPG which is 100 octane at least
Toomanytoys says run 14deg for LPG
Total advance on a 2.1 distributer therefore should be 16 + 14 = 30 deg
Seems I must recheck my figures I got 40 deg.
That was with vacumn on total advance.
Can the mechanical and vacumn work together when reving the engine
vehicle stationary.
Therefore 14 + 16 + 16 = 46

On Wiki for Aircooled it says that you can get 40 deg with vacumn + mechanical.

Follow-up comments (Simon)
Toomanytoys: Oh and dont be tempted to fit an 009 as they are useless for a type 4 engine..
not enough advance and not fast enough advance ramp..
From what I can remember reading, its not unusual to see 40 deg with all hoses connected correctly on a very light throttle... heard from a type 4 guru.

30 degrees sounds a bit too retarded for max advance.. I would have it at about 32-34 max mech (only, disconnect and plug vac hoses) advance, especially if running on LPG.

[HarryMann]

Can the mechanical and vacumn work together when reving the engine vehicle stationary.

If connected they will (work together), you cannot build up a load on an engine revving i in neutral so the vac will always be working to some extemt or other, it needs disconnecting to see just what the mechanical advance is..

I wouldn't woryy about the vac advance if its working, just ensure the cent follows the approx curve.

[Pickles]

Just tested my timing again
vacumn disconnected and plugged
2.1 distributer
set at 14 deg 800rpm
Max advance 30 deg 2400rpm

therefore ok

Vacumn reconnected 40deg max advance

[HarryMann]

That sounds about right, I will slightly alter those curves then to suit Simon's figurework and your proof of it. Still wortha swing either way though