Jfrahm

On an S2 I did it by making a timing tape on the balancer but that should be possible on a 968's pulley. I made a pointer from some wire or something.

Then I made fine sharpie marks in lifter bores and carefully found lobe center looking maybe 20 degrees +/- as TDC is a bit vague. I was able to measure some distance before and after TDC with a dial indicator and a stand. The WSM has figures for degrees related to valve open/close so I was able to adjust the cam timing to match the crank degrees.

Marking the lifter bore was handy as you can make three marks close together, let's say red yellow and green, and then you measure when you can see red and yellow but not green, taking care to have your eye in the same place (sight past another landmark like another wire pointer bolted to the head.)

The WSM says that the exhaust opens at 31 degrees crank BTDC and closes 1 degree ATDC so you know it's 33 degrees wide and you can extrapolate the lobe center (16.5 degrees BTDC?) and mark it on your timing tape. Your lifter bore marks can be somewhat random, you just look for lobe center with them. If the lifter hits the mark at 26.5 degrees and 6.5 degrees BTDC you're on. You want your marks to be in a steep part of the cam so the lifter moves a lot per crank degree. At lobe center it moves very little and likewise at valve opening, it's not clear what 'opening' means. That's why some specs give you crank degrees at 1mm valve lift or something useful like that.

Measure a few times, always turning the engine the same way, wipe off your marks and repeat if you like at a different lifter depth. Check against a piston measurement, which is harder due to bearing clearances and timing belt slack but you can get a feel for it.

Your TDC measurement is important of course.

Cloud9...68

I read Joel's post about five times, and still didn't understand more than about two sentences of it, which convinced me (not that I needed a whole lot of convincing) that I have a LOT to learn about the whole subject of cam timing, what it actually is, why it's done, etc. So I did some reading, and watched several youtube videos (they're always about timing Chevy small & big blocks, of course), and now, I understand maybe four sentences of Joel's post. Back to the books...

Vilhuer

This could be helpful as it describes factory timing method usage in 928.

Cloud9...68

Thanks very much! It's so nice that these are actually training videos, as opposed to just videos put up on youtube by amateurs (not that I have anything against these amateur videos - I've learned a ton from them over the years). I started watching the first one, and it looks very good so far, but have a busy day ahead, so I will try to watch them later on.

Overall, I think we have a great teaching/learning opportunity here which I hope will clear up a lot of the controversy and mystery surrounding the valve timing procedure on these cars. I have particular interest in the subject, because mine is a normally aspirated mostly-track dedicated car which I hope to race competitively in the not-too-distant future, so I want to make sure I've squeezed every last possibly horsepower out of the engine.

Let me start off with one very basic question, which you can ignore if the videos answer it: What is the fundamental purpose of doing the cam timing procedure? Since the exhaust cam is driven off the crankshaft by a belt, the intake cam is driven off the exhaust cam with a chain, and the relative positions of all three are clearly marked on the cams and on the front of the engine, why go through this elaborate procedure to "time everything in?" Is it to correct for small differences in timing belt and cam chain tolerances?