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72 Superbug - what's the prescribed ignition timing?

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bartg Casual Dubber

20 posts · joined Apr 2010 ·

#785666
Hi guys,

This should be an easy question for you. The car is a 72 Superbug 1600, vacuum advance distributor. What I'm trying to establish is how to interpret the timing marks on the pulley and what the correct timing is for this particular model.

There are 3 marks on the pulley arranged like so:

| ---------- | -- |

The gap between the left mark (L) and the middle mark (M) is about 12mm. The distance from the middle mark to the right one (R) is about 4mm.

From what I can gather they are:

L = TDC
M = 7.5 deg BTDC
R = 10 deg BTDC

Is that right? If not, then what are they???

Now, for the second part of my question -- what should I set the timing at? Is the setting the same regardless of the timing method used, i.e. static vs timing light? If adjusting at idle, should the vacuum line come off or leave it on?

I spoke to a guy at a local shop and he got me all confused. Said the left mark (the one I should use) is 7.5 BTDC and the one on the far right is TDC!! With the engine cranking clockwise, this just doesn't seem right...

Thanks
Bart
Bart

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 ·

#785672
Hi

Sounds like you have the wrong pulley, you should only have 2 marks.

You should have a mark that looks like its been bumped on grinder, that's TDC. This mark is on the outside edge of the pulley closet to the muffler.

The other mark should be a 7.5, its a shallow V on the inside lip of the pulley, it is to the right of the TDC mark.

7.5 BTDC is the correct initial setting, vacuum hose off.

Steve

bartg Casual Dubber

20 posts · joined Apr 2010 ·

#785703
Hi Steve
1303Steve wrote:Sounds like you have the wrong pulley, you should only have 2 marks.
OK, so if I were to sit the proper pulley on top of mine, how would the marks align?
1303Steve wrote:7.5 BTDC is the correct initial setting, vacuum hose off.
Are static and timing light settings identical? I have a light but don't trust it.

Cheers
Bart
Bart

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 ·

#785716
bartg wrote:Hi guys,

This should be an easy question for you. The car is a 72 Superbug 1600, vacuum advance distributor. What I'm trying to establish is how to interpret the timing marks on the pulley and what the correct timing is for this particular model.

There are 3 marks on the pulley arranged like so:

| ---------- | -- |

The gap between the left mark (L) and the middle mark (M) is about 12mm. The distance from the middle mark to the right one (R) is about 4mm.

From what I can gather they are:

L = TDC
M = 7.5 deg BTDC
R = 10 deg BTDC

Is that right? If not, then what are they???

Now, for the second part of my question -- what should I set the timing at? Is the setting the same regardless of the timing method used, i.e. static vs timing light? If adjusting at idle, should the vacuum line come off or leave it on?

I spoke to a guy at a local shop and he got me all confused. Said the left mark (the one I should use) is 7.5 BTDC and the one on the far right is TDC!! With the engine cranking clockwise, this just doesn't seem right...

Thanks
Bart
The local guy must have thought the engine turned anti clockwise... lol

If the first one is TDC... then the next one should be 7.5 and then 10 degrees..

Timing Light- do You mean a strobe type timing lamp with a sensor on number one spark plug lead???
then they cannot be incorrect as they are activated by the voltage going thru the spark plug lead...

7.5 is the normal timing mark for SVDA dizzies..

vacuum hose OFF... and pipe on carby blocked off..
so no air is being sucked in..

a small piece of hose with a nail or rivet in it will be the trick..

so the dizzy only works with centrifugal force...

cheers

LEE

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- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 ·

#785736
Hi

I'm not sure how the marks would line up. I guess that you have an early pulley. which may have 5 ATDC, TDC and 7.5 BTDC, who knows but this is a basic thing that you need to get correct.

Does your pulley have the grinder mark on it?

I will, take a photo of the correct pulley from a 72 bug, btw, 71 Bugs had 5 ATDC.

If your budget allows a pulley like on Lees car is good investment or take the bolt out the crankshaft end and line a known pulley up against the keyway.

You should always double check the markings on after market keyways.

Static or timing light should be the same, it also pays to recheck the timing after the motor has warmed up, they often retard.

Steve

bartg Casual Dubber

20 posts · joined Apr 2010 ·

#785814
Hello Lee and Steve,
68AutoBug wrote:The local guy must have thought the engine turned anti clockwise... lol
I hope he was just having a bad day. After 20 odd years working on these engines he really should know better. :-/
68AutoBug wrote:If the first one is TDC... then the next one should be 7.5 and then 10 degrees..
Going by the spacings between the marks, it makes sense. I will try to get hold of a calliper to measure the pulley's diameter and work out the number of degrees between the marks.
68AutoBug wrote:Timing Light- do You mean a strobe type timing lamp with a sensor on number one spark plug lead???
then they cannot be incorrect as they are activated by the voltage going thru the spark plug lead...
Mine's one of those with an advance dial and I haven't got complete confidence in its accuracy. I would prefer to set the timing statically and use that as the basis for testing the strobe (unless I can find another light to compare with).
1303Steve wrote:I'm not sure how the marks would line up. I guess that you have an early pulley. which may have 5 ATDC, TDC and 7.5 BTDC, who knows but this is a basic thing that you need to get correct.
It can't be this type of arrangement. The middle mark on my pulley is a lot closer to the right mark than it is to the left one.
1303Steve wrote:Does your pulley have the grinder mark on it?
Nope. Just the three v-shaped notches on the inner lip.
1303Steve wrote:Static or timing light should be the same, it also pays to recheck the timing after the motor has warmed up, they often retard.
That's good info. Thanks Steve!

Bart
Bart

68AutoBug Beetle Restorer - Experience over 138\% - YIKES --

11,654 posts · joined Aug 2002 ·

#785840
7.5 to 10 degrees is OK...

set the static timing then use Your strobe timing lamp and set it accordingly ... as they should both be the same..

I have a dwell meter that I haven't used as I prefer to set points with a gauge... that's hard enough.. lol

cheers

LEE
- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---

bartg Casual Dubber

20 posts · joined Apr 2010 ·

#785929
That is precisely what I plan to do.

Cheers
Bart

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 ·

#785936
Hi

I prefer to set the points by eye and then re check with the dwell meter, the dwell meter averages out all four point openings.

When I worked in a VW shop if we had a regular customers cars to change the points on, we often found that after changing the points and setting to the correct dwell and then after a test drive the timing would be spot on.

The points rubbing block wears down over time and retards the timing, that's why electronic conversions are so good.

If your using a strobe light you can check check your vacuum advance, rev the motor up to about 1500 - 2000 rpm and pull the vacuum advance line off, the timing should retard.

Steve