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Sat Sep 01, 2007 12:04 pm

I seem to get myself confused every time i tune up my vw's a stock 74 & 73. The Crankshaft pulley has two different types of marks. The marks in the forward engine side are deeper "v" shaped notches. The mark on the outer rim of the pulley to the back of the car is a wider shallower mark. I have always assumed the wide mark to be TDC & the "v" mark more a timing mark.

Doe's this sound correct?

Sat Sep 01, 2007 12:07 pm

This should help.

Sat Sep 01, 2007 12:15 pm

Yep... dimple is TDC...

I have never seen a pulley with all the marks on it like in Glenns pic though... most of the time you either see the notch to the left of the dimple which is 5 ATDC ( orginally a DVDA distrubutor) or a single notch to the right which is 7.5 BTDC ( SVDA) VW did produce at least 5 pullies with different notches in them that I know of... maybe more.

Sat Sep 01, 2007 12:16 pm

Thanks Glenn, That's as i thought. So in theory if i run the engine up to 3500rpm with stock dissy the Tdc mark should move 28-30 deg. to the left using a strobe?

Sat Sep 01, 2007 12:34 pm

Nope the stock mark is for timing at idle, not max advance.

Sat Sep 01, 2007 12:43 pm

Yes i understand about the existing notch. If you added a mark 1.8" to the right of TDC or 30 deg should that be the max advance at 3500rpm?

Sat Sep 01, 2007 3:17 pm

keifernet wrote: Yep... dimple is TDC...
I have never seen a pulley with all the marks on it like in Glenns pic though...

I have, but not from the factory. That image is actually derived from a picture I put together of a pulley I made those marks on myself. ATK/Vege rebuilt motors come with all those marks on them, but the notches aren't as nice as the ones I made. No I made those marks just to illustrate the common timing mark locations in relation to one another.

If you've ever seen the John Muir "Idiot Book" it has a good chart that shows the timing marks as well, I scanned a snippet of that chart before:

Sat Oct 06, 2007 2:02 am

Print, cut out and draw marks on your pulley where needed.

Sat Nov 17, 2007 7:34 pm

This is the pulley (stock) on my engine:

It has the three 'v' notches on the rear of the pulley, but no dimple that I can find (that dark spot on the front of the pulley is just a dark spot, not a dimple). Which of the 'v' notches is TDC, or is mine supposed to have dimple between the first and second 'v'?

Wayne

Sat Nov 17, 2007 9:23 pm

lewis71bug wrote: This is the pulley (stock) on my engine:

It has the three 'v' notches on the rear of the pulley, but no dimple that I can find (that dark spot on the front of the pulley is just a dark spot, not a dimple). Which of the 'v' notches is TDC, or is mine supposed to have dimple between the first and second 'v'?

Wayne

It's the V on the far left. It goes 0,7.5 and 10 degrees or left to right o, 7.5 and 10.
The picture of the pulley with the dimple that Glenn posted is not original VW.

Tue Jan 08, 2008 7:03 pm

What about those of us who don't have the "dimple"??? Is there a way to tell if we have the proper pulley (other than pulling the dizzy or checking the valves?

Tue Jan 08, 2008 11:34 pm

Well, checking the valves won't tell you exact TDC anyway. You'd have to pull a spark plug, put something into the cylinder to touch the cylinder and watch it as goes on either side of TDC (turning the engine over gentlry on either side of TDC that is) to visually see where TDC is.

Wed Jan 09, 2008 7:14 am

elektronikbadger wrote: What about those of us who don't have the "dimple"??? Is there a way to tell if we have the proper pulley (b

And pulling the distributor does not tell you anything either...

AFAIK only the 71 and later pulley's ( like in my picture posted earlier in this thread) have the "dimple" Some models were notched 5 ATDC for DVDA and others 7.5 BTDC for SVDA

This has always caused problems for owners or ill informed/non VW mechanics when an 009 or any other distributor besides the correct one was installed and the timing set to the factory marks on the pulley.

If yours has just notches and no dimple it is an earlier ( or possibly aftermarket) pulley and you can use a chart in one of the manuals ( like glutamodo posted part of one above) to find what marks on your pulley mean. BUT you still have to time it for the distributor you are using.

Thu Jan 10, 2008 5:50 pm

Is there any part numbers on the back of the pulley? Mine has one single mark and a VW logo almost directly below it on the face (I'm guessing it's 7.5 BTDC based on the engine code) but I'd like to be sure. it seems to me that my dizzy drive gear is not in the correct position and I'd like an easy way to find TDC so I can actually check it.

A degree pulley is always an option... but it takes away from the stock look.

Thu Jan 10, 2008 6:53 pm

No part numbers on the crank pullies, just that VW stamp usually.

Sat Feb 09, 2008 7:01 am

The dizzy rotor does not have to be in the exact position as shown in most illustrations. A stock dizzy will have a very faint mark or indentation along the top of the dizzy where the cap sits. The rotor button should point to that mark when the #1 cylinder is at TDC.

Tue May 06, 2008 7:30 pm

I have a '72 super with the single dimple in front and a notch to the left for 5 ATDC.

On the pulley is stamped the VW circle and a big letter D.

What's the D mean?
Does it have a meaning?

Tue May 06, 2008 8:25 pm

I don't know what the D meant for sure, but it was on more than just one variety of timing-marks pulley.

Tue May 06, 2008 9:44 pm

BrockGrimes wrote: I have a '72 super with the single dimple in front and a notch to the left for 5 ATDC.

On the pulley is stamped the VW circle and a big letter D.

What's the D mean?
Does it have a meaning?

Deutschland?

Wed May 07, 2008 2:52 am

Yeah, I was thinking that might be it. Or I wonder if it's a size code they used once they changed the diameter of the pulley early in the 40HP era.