Porsche 944 S2 Cab Rebuild

[jokeruk63]

Hi folks,
First post here, so hello to all.

I'm (finally) rebuilding my 944 S2 Cab after a cam chain tensioner failure in around 2010 took it off the road. I did much dismantling at the time but lost the will to live somewhat and now much older, divorced (nearly) and definitely wiser I am attempting to put all the random parts back together.

Actually it's not as bad as that. It appears after I got the head off that there was no valve/piston strike. The original cams were nerfed and stripped so I managed to get a complete S2 head off ebay with cams for £50!!!

I have the head back on, manifolds and stuff reconnected and am at the point where I need to get the cams on and get it retimed. I have new belts, rollers and a water-pump to fit, but the simplest of problems is causing me much stress - lining up the flywheel timing marks.

I can see next to nothing through the top viewing hole - maybe a raised notch with a dip either side. So I removed the starter motor and lined up the notch on the flywheel with the hole at the bottom of the bell-housing and looked expectantly through the hole in the top of the engine, but still nothing obvious to see. The problem is with the notch at the bottom there is sufficient leeway (I would have thought) to misalign by at least a tooth as there is no alignment mark at the bottom, just the notch.

I accept that I am probably being dim and that my skills are extremely rusty however, If I could get some guidance on finding exactly where to lock the flywheel I would be really grateful. I can obviously tell that with the bottom mark showing in the viewing hole that the car is about at TDC, but to me "about" could be +- 3degrees.

Thanks in advance



Steve
1992 Porsche 944 S2 Cab
1982 Land Rover 110
2004 Mini Cooper S

[larrylamb11]

In you really can't see the TDC mark, sounds like you are forced to fall back on the old fashioned way of determining TDC using a dial indicator and a degree wheel.
Affix degree wheel to front pulley and pointer to block, place rod for dial indicator down plug hole to contact top of piston, rotate engine to establish rough TDC and zero out dial indicator. Rotate engine backwards a good 90 degrees then forwards again until piston is once again acting on dial indicator. Select a handy/memorable dial indicator reading whilst still on the rising stroke and stop engine at that point - read off the degrees on your degree wheel. Continue rotating engine upto and through TDC, then watch dial indicator, stopping rotation at the same handy dial indicator reading - read off the degrees on your degree wheel.
You now have two degree wheel readings, one ahead of and one behind TDC (both at exactly the same piston height but one on the up and one on the down strokes of the crank). Add these two readings together and divide by two to give you the degree wheel reading that is your TDC point - rotate engine to that using degree wheel and pointer.

If you don't have a dial indicator you can use the 'hard stop' method where you screw a rod into the plug hole to contact the top of the piston in the same way (note: no force is required, you are just looking for a physical method of stopping the piston at a repeatable point). Rotate up to the hard stop, note degree wheel setting, rotate counter-clockwise and back up to the hard stop, note degree wheel setting. Divide by two as before.

[cd1957]

Hi there is no timing mark on top of the flywheel, the lower one is the TDC mark.

You would need to set cams and correct tdc setting with 2 dial gauges,1 for tdc and other using valve lift on inlet for cylinder 1

Chris

[LarJammer]

There is a notch in the flywheel for tdc - setting that is the easy bit. As Chris says, you then need 2 dti's to set the cams up as the pulley is adjustable.

[jokeruk63]

Thanks for the responses folks, been trying to respond all week but posts from newbies were blocked.
Ive ordered a second dial gauge (although the first one was was still virgin)
Hoping to crack on this weekend- but with great care

S