shmucklebuckle

I'm doing my headgasket (again...don't ask). I've got the head off.


Before I took it all apart, I found TDC (instructions @ Clark's Garage) using the 5mm window on the bell housing under the car, and verified TDC with the timing mark on the camshaft timing gear.

Looking at the #1 cyl., if I remove the flywheel lock and turn the crankshaft, the piston still has a 1/4" of travel to make in the upward direction, meaning #1 is not in TDC when the cam and flywheel say that it is.

Should I put it at TDC visually, by looking at the piston come ALL the way up, or should I put it at "TDC" according to the marks?

streckfu's

I always put it TDC by using a dowl (long scredriver). I stop rotating as soon as the piston stops rising (remeber that there is a couple of degrees of rotation where the pistion remains at TDC). I always line the cam up with the mark as it always ends up within half a tooth of TDC.

Legoland951

That is not possible unless the flywheel is improperly installed, which is difficult to do to say the least. TDC means piston #1 at TOP dead center. Every other marker is irrevelant. Other than than #1 piston at top means you will most likely be bending valves. Take a picture. If your flywheel is installed improperly, the last time you installed the head would have bent valves so check your head for valve damage.

streckfu's

How did the car before the headgasket went?

KuHL 951

I thought that my TDC cam mark didn't line up with the one in the bellhousing window either. Then I actually got right on top and looked at the opening square on and it was within half a tooth on the cam mark. It looked way off when looking at an angle from the fender though. The mark on the bottom of my flywheel is very hard to see and I ignore it.

streckfu's

I don't go by the flywheel mark after using the above method.

shmucklebuckle

Well, I may or may not have bent some valves the first time around, but it doesn't matter too much to me now, because I bought another head w/ valves already installed and am using it this time instead, so no extra loss here.

Instead of using the window on the bottom of the bell housing, I checked the top of the bell housing with the "OT" line, and it is in the right spot when I put cyl #1 at TDC, and my balance shaft sprocket agrees with this as well, so that is where I will leave it when I re-install the cam tower.

Porsche-O-Phile

Very weird. I noticed last time I had my early '85's belts off that the "OT" mark visible from above was correct (lined up with the TDC using the "stick" method and the cam gear mark, etc.) However the mark that's usually on the flywheel visible from BELOW wasn't there. Weird. Maybe the PO machined it off by accident? I looked long and hard and I'm sure it ain't there.

Granite 944

It ISN'T THERE, on all cars, and flywheels. Bellhousing window mark is ALWAYS there. Depends on year/make/model of engine, and flywheel used in it. Mix and match! Not always.........what ya expect.

apierce918

cant the flywheel only go on one way? my car has a little pin off center that has to line up if you want to put the bolts in anyway

Legoland951

The flywheel has a pin and if someone broke the pin or removed it, it can be installed improperly. That is why I stated it is difficult to do to say the least. I thought he meant the OTC timing mark on the top was not "on" when the piston is at TDC. I never go by the bottom and didn't even know they have instructions to look for a mark that is not there.

L8 APEKS

Do not pay attention to anything except the OT mark (or rather, the stripe just next to it). My balance shafts were WAY out of timing and we didn't notice until replacing the timing belt. Cam and crank were OK, but the balance shafts faced opposite directions. Car ran smoother after fixing that.

And remember, you have to be looking at the OT from directly over it, not at an angle, to watch for the stripe lining up with the black needle inside the opening.

If you need a hand, throw up a post. Sounds like you live nearby.

Hawk36

When turning the engine to find TDC, which direction to you turn when facing the engine? Does it matter?

apierce918

i always turned it clockwise

KuHL 951

When I had my flywheel off I painted a yellow band on either side of the OTC mark with a black mark on the line. Makes it really easy to see now in bad light.