I am in the middle of the timing belt install on a 02 WRX. My question is, once everything is put back together, and the engine is turned (by hand) over until the marks return to each pulley, how far off should they be? If the belt was installed with all the marks lined properly, once they leave that spot would it be different? I don't plan on cranking the car until I get an answer, so please reply soon. Thanks for the help.

They should be less than a tooth off by my calculations. BTW, which marks are you referring to? The slots on the cams and crankshaft pullies? Or marks you made yourself before you took the belt off? If you line up all the marks like it says in the service manual, that should be TDC right? You like up all the marks on the pullies to the engine, then you line the marks that the new timing belt came with to the intake cams and crank pully, Count the teeth so you know they are spaced correctly. Pull the allen wrench on the auto tensioner and bam your done? This isnt the whole precedure however. Thars how I did mine, per the service manual. But then again, I havent truned mine over yet... :) Will be doing today or tommorow.

Oh, you might try hand cranking it over a couple times, sometimes with engiens (dont know about EJ20 yet) when you think you are back at TDC again, you are actually 180 degrees off. But if you are hand cranking it, and you arent hitting any real hard spots (over and above compression) the marks should eventually line back up. Otherwise the belt is streching and why even have one.

Yeah, I did as per the manual. Line up the pulleys to the engine, then the new belt to the pulleys. Once I got the tensioner back on, I hand cranked it 2 full cycles now, (when dotted line returns to crank pulley) and still no dice. Its a Greddy belt BTW. I took it back off, and have found it to be 12 teeth longer than the stocker. I would think this has an incredible amount to do with it, and am on the phone trying to get it taken care of.... I'll keep you updated.

Man I never did that with mine, BUT I used an OEM subaru belt.. should be ok. :(

Its a good thing you cranked it around man!!

Randy

There are different belts for the DOHC and SOHC engines. Glad to hear you hand cranked or O-Boy it could have been a big expensive problem.

I was told it would be ok, and that most DOHC vehicles, took anywhere from 150-1500 full revolutions before the lines ever line back up. I should have it together one day, I'm replacing the clutch as well, yay.

150+ revolutions to line up? I think not!!!!!!!!!!!!!!!!!!!!!!!!!

Why not? Unless the number of teeth on the belt is low integer multiple of the tooth count on the crank pulley it's not going to happen anytime soon...

Easy enough to figure out: count the teeth on the belt and crank pulley; find the lowest number (revolutions) evenly divisible by both.

Line up the marks on the pulleys, put the belt on per their alignment marks. Once it's back together, if you manually turn the crank you'll notice that the belt marks will not be in the same positions. That's okay. Just make sure that your mechanical parts, i.e. cam sprockets and crank timing sprocket all line up approximately where they should. The belt marks are there just to help align the sprockets. Trust me, it will be fine! I just built a motor and pulled my belt off three times because of this, only to realize that the marks on the sprockets which would line up every time was what was important. Also, the driver side intake cam (the one on top) which is the metal sprocket can be deceiving. Make sure that the double hash marks are going down. The other hash marks on the plastic sprockets are easy to identify though.

It would seem to me that if the intake valve(#1 Piston) are suppose to open at X degrees of crankshaft rotation on the intake stroke that is a constant. So every 2 crank revolutions of the crankshaft ALL pulleys (cam and crankshaft) should like up-It is a fact that must be true if the motor is to run correctly. I dont'd care what the belt marks are doing. They are put on ONLY if your reusing a used belt and want to put it back in the same orentation.

It would seem to me that if the intake valve(#1 Piston) are suppose to open at X degrees of crankshaft rotation on the intake stroke that is a constant. So every 2 crank revolutions of the crankshaft ALL pulleys (cam and crankshaft) should like up-It is a fact that must be true if the motor is to run correctly. I dont'd care what the belt marks are doing. They are put on ONLY if your reusing a used belt and want to put it back in the same orentation.
That makes a lot more sense... a timing belt is there for timing.
(currently in the process of redoing my timing belt and front engine seals)
so all of this is good to know...

What GravelRash said. And I suspect the largest common multiplier is indeed 1, so that the sprockets and belt wear evenly. Same as with ring and pinion.