Cam shaft removal 968

[FIREMN]

Howdy, I am getting ready to remove the cams and Vario cam unit so I can remove the head and inspect the cylinders.
I got the cheese head tool today, so I am chompin at the bit to see the pistons.

I ordered the WSM but it wont be here in time. I am having a lot of trouble finding specifics for the 968.

First off, I am not sure that the cams are timed correctly now, so I am not comfortable spinning the crank to TDC. I don't want to smack the valves.

I understand that to remove the head I have to take the cams out. I have read that the cam saddles need to be loosed in sequence so as to not bend the cam shaft. I am assuming the opposite of the torque sequence.

So, does someone have the torque sequence?
I also need to source the chain and pads.
hopefully the cams look good.

I would appreciate an info or links to 968 sites,
thnx

[rhett]

Hi there, I am making an assumption here that the removal of the 968 cams is going to be a very similar operation to the removal of the 944 16V cams (apart from the variocam assembly). So, there is no prescribed sequence for the slackening of the cam bearing bridge (cam saddle) bolts. I have looked at the official Porsche WM and all it says is loosen or tighten evenly. I recall when I did mine I followed my own sequence and slackened the bolts one or two turns at a time - so nice and even.

I am sure you are aware of the following advice, but just in case:

Make whatever marks on the shafts and other items you see fit to ensure all the parts can go back together exactly as they are now and take photos for reference.

Always put some pieces of cloth in the oil ways to stop washers, bolts and other stuff dropping into the sump.

Always ensure the cheesehead bit is fully down in the bolt head, so remove any oil with a tissue, then give the bolt a tap with a hammer to 'wake it up' (but not too hard!).

Note that the bearing bridge are unique to your head and position on the cam, do not get them mixed up, so check the numbers stamped on them for re-assembly.

Take your time and it should all come apart relatively easily - for a Porsche!

[rhett]

Here are a few links to web pages that might be of interest:

http://www.jackals-forge.com/968_cams_inspection.pdf

Setting the Camshaft Timing on a Porsche 968

Picasa Web Albums - David - Porsche 968 t...


928 Tech Tips

Hope they provide some help and tips here...good luck!

[FIREMN]

Perfect. That is exactly what i needed!!!

However, just finally found out that the reason it wasn't put back together is that a gear wheel inside the vario cam adjuster is toothless.
it lost its teeth when the timing belt skipped which allowed the cams to skip. So, i now need to scour the earth to find a replacement vario cam. or a dead one to rebuild.

[Contadino]

I made my own cam hold down blocks from some 2x2 oak boards. Very easy to make and IMO made removal and installation easier and safer. I used TDC adaptors for the spark plug holes and threaded rod.

[rhett]

^^ Very nice , might just make a couple of those myself for when I do the lifter set later this year. Just goes to show what a brilliant resource this forum is...

[rhett]

Originally Posted by FIREMN

Perfect. That is exactly what i needed!!!

However, just finally found out that the reason it wasn't put back together is that a gear wheel inside the vario cam adjuster is toothless.
it lost its teeth when the timing belt skipped which allowed the cams to skip. So, i now need to scour the earth to find a replacement vario cam. or a dead one to rebuild.

Hi, just a thought...Isn't the variocam adjuster a hydraulic device operating with oil pressure regulated by a solenoid valve? In that case there would be no gear wheels to strip. Are you getting this info from a mechanic who has actually had experience of this device, or just the chap who took it apart and left it?

Before you order a new component, perhaps there are some checks you can do on the old one to see if it does actually operate correctly? Someone on this or other forums might be able to help?

[FIREMN]

Yea, the info is from the guy who took it apart and left it. I plan on taking the Cams of as a unit next week. Then i will get to the bottom of it. I have to also take the motor out of my 928. So i am just trying to figure the logistics of having 2 non running cars to work around.

Looking at the breakdown, I dont understand what he was talking about either.
http://www.jackals-forge.com/968_cams_inspection.pdf

[FIREMN]

What adapters did you use for the sparg plug holes?

[Contadino]

I used the top dead center indicators from Summit racing and some threaded rod from Ace Hardware.

[rhett]

Originally Posted by Contadino

I used the top dead center indicators from Summit racing and some threaded rod from Ace Hardware.

Hi there, I have never come across a TDC indicator, what does it look like and are they generally available??

[FIREMN]

So, I made the tools to hold down the cams also.
I used spark plug non fowlers. These are adapters that are also found in compression tester kits.
Basically it is a threaded bushing. I had trouble sourcing the correct all thread, so I had some 1/2x13 all thread welded to the adapters. it worked great. I found the adapters at NAPA,,