1972 AE 1600 DP timing

[Dirtylittle70Bugger]

I have a stock 1972 AE case 1600 dual port with a Bosch 0 231 167 070 DVDA distributor (1974 I think) and a Bocar Solex 34 pict 3 carb. The points failed on me (gap closed too much) on the way home the other day. So I reset the gap which made my idle high. So I checked my timing and it was way off. Like 20-30deg ATDC at idle. So I set my timing to 5deg ATDC at idle 850-900 rpms with vacuum lines attached like is recommended for this engine distributor combo. Now although the car seems to run ok. Its harder to start when warm, the engine seems to be running hotter then normal and my fuel economy is down a bit along with a loss in low end power. Is there a better time setup for this combo? The car ran better and cooler before the points closed on me. The gap and timing is e only thing that changed. Thoughts?
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I thought I was wrong once, but I was mistaken.

1967 VW Beetle, Java Green, 1500SP, Roof Rack, trailer hitch

[glutamodo]

you need to make sure your DVDA retard vacuum canister is really functioning - it is VERY common for the vacuum retard section to fail on those. At idle, with the vac retard hose connected, set it to 5ATDC, then pull the retard hose off while watching the timing - it should jump about 10-12 degrees instantly.

Oh, by the way, despite there being a vacuum retard fitting on the Bocar carb, it is set up for SVDA service. (the main difference being the size of the hole in the throttle butterfly. It's bigger if you have a DVDA and smaller on an SVDA) - with a function DVDA setup you need to let a bit more air to come through the throttle butterfly in order to allow decent idle adjustments. Mentioned as part of this thread- http://www.thesamba.com/vw/forum/viewtopic.php?t=365762&

[Randy in Maine]

Do this....

Remove both vacuum lines and time it to 28-32º BTDC (and I would do it to 30º in beetle) when all of the centrifical advance is in ~3500 RPMs.

Let if loaf back to idle and note (but don't change the timing) the timing at correct idle speed of about 850 RPMs. Since the timing light is still on there, make sure that the timing advance and retard is nice and smooth as the eing erev and retards.

Do both sides of the vacuum canister hold a vacuum when you test it with yoru hand vacuum pump? It should.

[Dirtylittle70Bugger]

No I haven't tested the vacuum canister yet. Which line is the vacuum retard. The on that runs to the front of the carb near the base? Or the one on the side near the top? Just so I understand this you want me to set the timing at @ 30 degs BTDC with the engine running at 3500 rpms correct? I've never set one that way before so I just want to be sure.
_________________
I thought I was wrong once, but I was mistaken.

1967 VW Beetle, Java Green, 1500SP, Roof Rack, trailer hitch

[glutamodo]

Ah, yeah, the retard line is the larger diameter hose that goes to the front-of-car side of the canister.

[Max Welton]

According to http://www.oldvolkshome.com/ignition.htm , the 0231 167 070 is for a Beetle 1972-1973 * 1600 Manual Trans.

Timing Set At:: 5deg ATDC @ 800-950rpm w/strobe, vacuum hose(s) connected

Max
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1967 Type-3 Fastback
Under the Knife https://shoptalkforums.com/viewtopic.php?f=24&t=151582
Home Stretch https://www.thesamba.com/vw/forum/viewtopic.php?t=767836

[ashman40]

As glutamodo explained, you need to make sure your vacuum retard is working before you set timing at 5 ATDC. It is only at 5 ATDC because the vacuum retard is taking away timing. If you remove the vacuum retard hose while at idle the timing should jump from 5 ATDC to around 7 BTDC. That is how much timing the vacuum retard was taking away. This means your distributor has a static timing around 7 BTDC. If you assumed your vacuum retard was working when it wasn't, you would end up static timing your engine at 5 ATDC! That is way too retarded and your engine would likely run hot.
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AshMan40
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'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[Dirtylittle70Bugger]

When I timed the car I didnt check the canister. I was unable to put vacuum to the canister last night due to rain. But I did do a quick suck test and I don't think it's holding. I removed both vacuum lines when I rechecked the timing. But not the retard line by itself and the timing didn't change. I'll try again today with just the retard line when I get home from work. So if it's a faulty canister, do you recommend that I replace it and go for 5 deg ATDC, leave it be and time to 7.5 BTDC or replace it with a single canister and time to 7.5 BTDC? Will running it with both lines connected and the retard side faulty affect anything if I time it like a SVDA setup?
_________________
I thought I was wrong once, but I was mistaken.

1967 VW Beetle, Java Green, 1500SP, Roof Rack, trailer hitch

[ashman40]

If either your vacuum advance or vacuum retard is faulty and cannot hold vacuum... you do not want to connect a vacuum hose to it, you will just create a huge vacuum (air) leak.

You should be able to easily tell if your vacuum retard is working by just starting the engine and while idling, remove the vacuum hose from the vacuum retard port on the distributor can and plug the end with your finger. If the vacuum retard was working while connected, disconnecting the hose will immediately add 10-12deg of advance. The idle speed should jump up a few 100rpm. Reconnect the hose and the idle should drop down again.
If the vacuum can was leaking air, reconnecting the hose would make it run bad. I could be difficult sometimes to tell the difference between lower idle because there is less power (degrees timing retarded), or lower idle because the mixture is too lean because of a vacuum leak.
The best way it with a strobe timing light. You will see the timing mark move under the strobe.


If the vacuum retard is broken but the vacuum advance still works, just set the timing to 7.5BTDC and run it as an SVDA.
If the vacuum advance is broken, disconnect and plug both vacuum hoses and run it as a 009. Set total advance at 28-32BTDC @3500rpm (or where ever it stops advancing).

How did you gap your points? What was the gap? Did you use a dwell meter (best option)?
_________________
AshMan40
---------------------------
'67 Beetle #1 {project car that never made it to the road }
'75 Beetle 1200LS (RHD Japan model) {junked due to frame rot}
'67 Beetle #2 {2019 project car - Wish me luck!}

[Mark MacKenzie]

What about the dwell?

[Dirtylittle70Bugger]

The gap, when open. At the time of fault. Was not even visible to the eye. I can't believe that it ran at all, let alone poorly. I reset it to .016 with a feeler gauge. Not with a dwell meter. The timing was set with a timing light and a standalone tachometer (sears auto anylizer) I do have a dwell meter I just didn't have time to play with it. What should the dwell be set at for this setup.
_________________
I thought I was wrong once, but I was mistaken.

1967 VW Beetle, Java Green, 1500SP, Roof Rack, trailer hitch

[Randy in Maine]

With new points, dwell should be 47º +/- 3º. I can get used points in the range also.

Always set the dwell or point gap before setting the timing or you are wasting your time.

I was a little jammed up when I replied earlier, ....

After you get the timing max centrifical advance set to about 30º BTDC when it is all in ~3500 RPMs. Repeat the experience so that you will know ahtat it is correct. Look for a smooth advance and retard with the timing light as the engine rev and retards.

I like to note the initial timing at idle, but I don't change it.

You can test the vacuum canister on both sides with a hand vacuum pump. I think they are about $20. They should hold a vacuum and actually move the points a little.

Then I hook up the vacuum lines and redo the test using the timing light. If you pretend that you are driving down the road at 3500 RPMs and start to go down a hill, you should be seeing max centrifical advance (from the 3500 RPMs) and max vacuum advance from the low load (downhill) on the engine. Expect to see about 42-44º under those conditons. Of course when you ask the engine to do any real work by putting your foot in it, the vacuum advance will go away immediately.

Then I note the timing again at idle conditons and set the idle to the spec using the tach function ont he meter. Then go for a ride and see how it in various conditons..

[Dirtylittle70Bugger]

Good info, I'll give this a try when I get home if the weather holds up. And yes, I set my timing after adjusting the points.
_________________
I thought I was wrong once, but I was mistaken.

1967 VW Beetle, Java Green, 1500SP, Roof Rack, trailer hitch

[Dirtylittle70Bugger]

So checked the vacuum canister and the retard side is not working. Doesn't hold and vacuum points don't move. Not change in idle speed with retard line on or off. Advance side works, doesn't hold vacuum indefinitely. But the points move and return. So I set the timing at 7.5 deg BTDC like a SVDA distributor and there is a noticeable difference. Runs a little quieter, better torque curve. We'll see how it is on the trip to work tomorrow. I may replace the canister with a old single canister I have lying around. Thanks all for the help and info. This weekend I'll try for a full tilt dwell, timing and carb tune.
_________________
I thought I was wrong once, but I was mistaken.

1967 VW Beetle, Java Green, 1500SP, Roof Rack, trailer hitch

[Randy in Maine]

Do this...

Plug the retard line at the carb. Set the timing to the 30º BTDC with vaccum hose(s) removed @3500RPMs. Rehook up the advance line, note timing at idle but don't change it. Set idle speed to the correct 850 RPms at idle.

Drive it and report back.

[Dirtylittle70Bugger]

Randy, will do. There was already a noticeable change in driving performance this morning on the ride to work. The idle may be a touch high but it started and ran well. I'll address that tomorrow when I dial everything in.
_________________
I thought I was wrong once, but I was mistaken.

1967 VW Beetle, Java Green, 1500SP, Roof Rack, trailer hitch

[Randy in Maine]

Just keep in mind that some set ups like 28º, some like 32º, some like something in between. Also engines that run "rich" like a little more advance.

You will find a setting that you and your car likes.