Great writeup, thanks. The 968 community is fantastic with all of the knowledge and openness to share.

Is this worth trying without the special Porsche tools, especially by a novice??? (I think I already know the answer). Other option is to pay my mechanic $1,000 to do the work...

 

GD, you need the tool for the BS belt tension. Besides that, you could get away without needing any special tools. After using the tool for so long, I can get to within factory spec just by feel. Some people actually do this by feel but I prefer using the tool.
Raj

 

I would not grind or drill, can not guarantee to not leave metal shavings.

If you are rebulding anyway then sure grind away to get the cams out is you want to. An old trick that works on these cheesers is ........

take a small sharp chisel punch and tap with a hammer, angling the chisel in a counter-clockwise direction. There is no loctite or should not be on these. They tap loose so easily...takes a minute at most. Chisel the head on the cheese in a closkwise direction. You would be surprise how little force it takes. You can even use the corner of the bolt head with ur chisel.

 

+1 chisel method works everytime

 

I'll try the chisel first next time. But are you talking about on the cam bearing bolts, or the 1 fat cam sprocket bolt?

When drilling bolts inside the engine, I keep a magnet right next to the drill, to catch the shavings. I know it probably doesn't catch 100% of it, but it does catch a lot.

 

For the 10 mm 12 point on the cam...with the valve cover off you will see a cut in on the exhaust cam the will fit a large crescent wrench. Hold the exhaust cam with that and then loosen the cam bolt. Makes it alot easier with again no grinding.

 

Well there are lots of ways to hold the cam while trying to open the bolt. Most people like to use the timing belt to hold it, I like to use a crescent wrench on the hexagonal front washer, you like to use a crescent wrench on the cam. But neither route will guarantee the bolt won't get stripped. What you really need is a quality cheesehead tool and a bit of luck. But thanks for the idea - I never thought of using a wrench right on the cam itself.

 

OK, where do I purchase the tool? I wonder if I could "rent" it from one of the two Porsche shops in town... doubtful I imagine.

 

P9201 show up fom time to time for approx $450 used. A new one is approx $650.
Raj

 

In that case, I think I will pay the professional to do it for not much more money.



Thanks Gents

 

You don't need the 9201 tool! Just use the Kricket from NAPA or Kragen.

 

First - and very belatedly - what a great DIY.

Second - I'm replacing my pads now - but am having a devil of a time compressing the variocam pistons fully. The first 2/3 of the way is quite easy. I can almost compress it with my hands as noted above. But then the pistons seem to reach a dead stop with 1/4" to go - and not enough slack to get the chain off.

I'm reluctant to compress with too much force with the big c-clamp I'm using.

Anyone seen this before? A mechanic I know who knows porsches but not so much our 3L engine said he thought it took a very long time - like an hour - to compress the pistons fully. A mechanic who knows our engine very well said he hadn't experienced any difficulty.

 

Ha. There is another possibility - I have actually compressed the pistons as far as they are meant to go - at least enough to get the chains off. Studying the pictures carefully at the head of this thread seems to indicate that the 9530 "tool" (ha! special piece of bent wire) does not actually hold the pistons in all that much of a compressed state - just enough to slip the chain off.

My new understanding of the sequence: 1) compress and hold pistons (special tool or some other way) 2) slip off chain and cams as a unit 3) remove chain from cams. Previously I was thinking 1) compress 2) remove cams from loosened chain 3) remove c-clamp, chain, and pads.

 

If you remove the cams/chain and variocam all together as 1 unit, you don't need to compress anything. The variocam is in a somewhat compressed state and can be slid off the chain. You need to compress it when you are fitting it back into the chain.
The bent wire is no standard wire, but a high strength wire. It is supposed to be removed after the cam followers have been installed and everything is into place.
Raj

 

Thanks Raj for your reply. Actually I made my own version of the clip using... wait for it...coat hanger wire.

Indeed I did remove cams and variocam as a unit - but the springs seemed so strong I didn't think it possible to just slip the chain off the pads, as you say, without a mechanical assist. At any rate, compressing and holding in the compressed state with the clip certainly makes it easier.

I'm still a little unclear as to how to use a c-clamp to compress the variocam without getting in the way of the pads... (step 46). Need to try that.

Here's my real question: shouldn't the re-install of the cams be done while the variocam is tensioned - keeping the chain loose and preventing the chain from pulling the cams inward? Or can the tightening of the cam bearings be done in such a way that this is not an issue?