Mechanical timing...please?

[tartan_rob]

SO I have been through Clark's Garage and the Porsche manuals and there does not appear to be a single definitive version of how to setup mechanical timing.

Assuming the mechanical timing was out on a 16v engine (nothing in sync). How would I go about re-setting it?


On every other car I have done this on, you align each camshaft to a mark (or similiar), set the crank to TDC, fit cambelt and away you go....

 

[J.C944TurboMan]

I think the 16V is the same firing order as the 8V ? Here is a link http://www.lindseyracing.com/LR/Parts/WIREORIENT.html

Checking the timing marks on my S2 , bottom of the gearbox there is a small slot that lines up with a mark on the flywheel and the top cam has a mark that lines up with the chasing .

Here is another good link http://forums.rennlist.com/rennforums/924-931-944-951-968-forum/720033-yet-another-timing-belt-tension-question.html.

When the top cam shaft and bottom crank pulley are lined up ? The rotor arm should point to number one plug on the distributer cap.

I believe that the rotor arm can be adjusted by losing the mount from the top Cam pulley ? I have never had to do this .

 

[colin944]

You use a dial gauge as per instructed by the work shop manual.I marked the position of the cams and the chain with an engraver. I also locked the cams and chain in place together using welding wire to hold the chain tight against the cams when I stored them. Then when I put it back together I only needed to use a dial gauge to check the cam positions.You can find the relevant pages by downloading the manual.I'll try and e-mail you the right section of the manual.

 

[tartan_rob]

Thanks guys. The distributor cap is different on the 16v. All the HT leads exit from the right.

 

[robdimond]

Did you lock the camshaft pulley to the 'propeller' behind it when you removed it? There is a 'fine' adjustment with the groove in the cam pulley wider than the key... the propeller behind is keyed to the shaft (with a right size key) so you can bolt them together to preserve the alignment.

The coarse adjustment hopefully you have right since you've run the engine! I used a dial gauge on #1 piston but there is also a flywheel marking, coupled with the notch on the cam pulley and rear metal timing cover.

If you've lost the alignment you need to use dial gauges as Colin says with one on the #1 piston crown and the other on (I think) #1 intake tappet. The procedure in the manual is clear as mud... maybe the original german makes more sense. Here is a 968 guide which makes it a bit clearer (but obviously using the measurements from the 944 manual!)

http://www.porsche968uk.co.uk/technical_tips/camshaft-timing-01.htm

If you look on youtube there is a video of the 928 32V procedure which is similar.