This chap has a few photos of i believe the same scenario, was 2/3's down on my phone.

http://scott-yoo.com/other/tb.html

Look down the back of the cam for an indent.

Sorry I can't be more specific, hope the pro stars appear soon

 

here are pictures pulled from the thread linky.

NOTE by counting forwards on the cam gears from the hash mark on the rear side of the cam pulley,
you can find where the cam pulley will line up at the 45BTDC mark its 4 teeth.

Usually a picture is worth a thousand words,
BUT if this isnt clear to you.

Then I suggest you get a knowledgeable 928 mechanic to assist you with eyes on,
as now is the most expensive part of the job to get correct,
a failure will cost thousands to put back right.

NOTE last picture is how the crank damper should look when its at 45BTDC.

NOTE its not uncommon to have the numbers turned around,
thus the damper would be on backwards.

so verify your damper numbers look like these

 

I understand the picture, not certain I understand your terminology when you say "hash mark" on the back of the pulley, my pulleys have a v shaped notch cut in the back that, according to my WSM is meant to line up with another v shaped notch in on the plate that backs the pulley and is attached to the head. These marks are to be line up exactly with the crank at 0 degrees TDC on #1 cylinder.

It's the four tooth offset I've never heard of before. Maybe the entire thread you quote discuses the reasoning? I'm working on an '85, perhaps this is something that doesn't apply to that MY?

 

You are confusing yourself unnecessarily. The cam timing marks on the gears line up at TDC so at 45 degrees they are 4 teeth off centre. After you get the belt on as you have been instructed, move the crank to 0 degrees and you should be lined up.

 

Thanks Dad, your words add much to this discussion

 

Are you trying to tell me the cams rest 4 teeth back from the alignment notches and the easiest way to set the belt is to rest both of them 4 teeth ahead then install and tension the belt?

 

Yep, I was confusing myself unnecessarily. This I understand. I'd forgotten the marks are at TDC, not 45 below TDC. Thanks. Last time I did this was over a year ago.

 

You know, my thanks ought to be a little more enthusiastic. Thank you both, ALOT! This is something that should have been in the WSM since it very explicitly instructs you to move the crank to 45 before moving the cams, then tells you to install the belt at TDC and line up the notches at TDC. Very confusing, nowhere is this "trick" mentioned.

Many thanks. This makes installing the belt a whole lot easier!

 

BTW, for 15 years my nearest "qualified Porsche mechanic" was 200 miles away in Salt Lake City. Under those conditions you either become a qualified mechanic the hard way or you sell the car for scrap.

It's for reasons like mine that the membership fees for this forum are ridiculously cheap and completely invaluable.

 

I am glad the light bulb has come on,
hopefully no damage has occurred ,
work slowly and if you have a question stop and post it,
someone will assist you

 

Sorry I missed the last part of the discussion. I was away from a computer for a bit. Yes, I think I would back the cam bolt off and retorque correctly.

Stan appears to have gotten you squared away. But I hope your cam gear teeth do not look like the ones in Stan's first two pictures. Those gears are just crying to be replaced, which I'm sure has already happened.

 

maybe its the 4 teeth equating to 45degrees that wasn't clear. remember, the cam pulley with 4 teeth is really only mechanically 22.5 degrees, but because the cams move for a 1:2 ratio, to the crank.... to move 22.5 degrees, the crank has to move 2x.... so 4 teeth would relate to 45 degrees on the crank

you would use the white paint marks not the notches which are reserved for checking at 0 TDC and line up with the yellow marks.

 

It was clear in everyone's mind but mine Until Dad pointed out that I had made a fundamental mistake by attempting to use the machined in notches to synchronize a crank set at 45 degrees, when the notches are meant to be used at 0 degrees, the light didn't come on.

I knew this, however I became confused and anxious when the belt slipped off unexpectedly. I reverted to my last experience timing the cams, which was performed with the crank at 0. I panicked. With a little help from my friends I calmed down. The car is going to be fine in a few more hours

Thanks to everyone who helped me make it through this crisis.

 

Scott,
If you don't feel good about the 4 teeth thing, since you have the crank at 45 degrees, you can move your cam gears to the marks for TDC, then move your crank to TDC (0) and install the belt. Your valves are safe and you have everything lined up exactly correctly. This is the way I do it.

 

we have all been there.... great to hear you go it all figured out now