Andy Artz

I'm going nuts trying to get the engine of my 1987 944S lined up. I recently got the car when a friend of mine lost the timing belt in it. Everything is in order except I can't find TDC. In the porsche garage site I found out there is a "TO" on the flywheel (when looking in the rectangular window near the back of the engine), but I can't find this in my car. I noticed there are two windows, one round, and one rectangular. They both have short teeth that roll by, but no lettering. Can anybody help me out?

Tabor

It should be the square hole. And I think it just lines up with a line. It is hard to see, you will need a flashlight, and to turn the car over slowly.

If all else fails stick a screw driver through the spark plug hole of #1.

webberman

There is another way you can find it. Underneath the car where the clutch housing meets the block there is a small notch at the very bottom maybe 1 cm wide by about 1/2 cm deep. When your motor is at TDC there should be a small notch in the flywheel visible through this opening.

When I rebuilt my engine I triple checked TDC by the following steps.

1. install the ditributor cap rotor if it is not already on there and figure out the approximate position the rotor should point in for the #1 cylinder to fire, then rotate the motor to that spot. That will get you atleast in the ball park.

2. I find it easiest if I am working alone, to get under the car and rotate the motor with a deep socket and breaker bar on the crank pully nut with one hand while locking through the slot under the clutch housing for the notch to come into view.

3. As a final check I usually now peer through the window on the clutch housing that is on the top side and look for the TDC mark. On my motor it is a line with the letters O.T. stamped by it.

Robert
86' 951

webberman

Duh! Sorry about step 1. Since you don't have your timing belt on yet that won't work! But try looking through that notch in the bottom, that will work if you vcan get under there!

rplencne

The screwdriver (or preferably something less abrasive) down the #1 plug will get you close, but make sure you're on the compression stoke (and not the exhaust stroke) or you'll be waaaaaaay off.

-Bob P.

Andy Artz

#1 plug is closest to the front (where the belts are) right? (just wanting to double check that). I've tried everything that's been suggested so far with no luck. Will the TO be in the middle of the rectangular hole? Or off to the side? Big or small? Is it just scribed into the metal? Could it be covered with dirt easily?

Thanks for all the help guys. I'll just have to keep looking I guess.

DanD

Andy,
Look at these photos and see if this helps any.

Dans belt change photos

Remember to go slooooow when turning over the engine. Any contact can be bad.
DanD

Tabor

Yep.

David J. Harrington

If the belt is off (so the crank is not connected to the cam), it doesn't matter what "stroke" your engine is on. It doesn't know the difference. Anytime that piston #1 is up in the clyinder (verified with the wooden dowel in the spark plug hole), the flywheel marking will be very close.

Dave