Imo000

Did you tighten the timing belt gear bolt? Even if the bolt is loose and the keyway is in place, the cam gear should not move much (just a few degrees the most) before the camshaft start to turn. Something is really off here. I really hope you didn’t crank the engine over with the starter cause that would most certainly result in bent valves. Also, it’s almost impossible to tell just by looking down the spark plug hole if a valve is bent or not. They usually don’t bend that much.

Can you take a picture of the cam gear and the camshaft, maybe we can see something that will shed some light on this?

Cam shafts are cast iron, they susally break and not bend. When you loosened the cam caps the pressure from the valve springs was released and you were able to turn them a little easier and this is normal. Now tighten them back up before the force of the all the valve springs loading at different pints of the cam ends up breaking the cam in half.

Is there anyone from Rennlist living close to that can take a look at your problem?

Clint's 944

OK here are some pictures...I've already taken the cam gear off again to check if the woodruf key was there. I am putting it back as I post this.
I lined up according to Clarks garage and Joseph Motro writeup here on Rennlist. The bridges are installed as the head marks indicate. I loosened and tightend all the bridge bolts 1/4 turn at a time.

The intake cam is just not turning....

Imo000

Ok, when you had the gear on the cam, did you install the 3 little 6mm bolts too before you tried to turn the cam over? You need to have those in there with the rotor to properly clamp the cam gear down. Just remember that turning the cams over by hand requires quiet a bit of effort. You are turning two cams with one bolt.

Clint's 944

No, I took them out because I thought that was what the woodruff key was for...

be right back....keep your fingers crossed!!!

Clint's 944

OK, little bolts in... same thing. I cannot turn it by hand...I've put about 100lbs of torque on it and NO absolutely NO movement. I put the timing belt on and it will slip over the crank, probably going to have to buy another belt now...

It's the intake cam....it will not budge. Where else can I look?

Clint's 944

One other bit of info...

I just remembered that when I was taking down the head, I had noticed that the cam bridges were out of order. The PO had the top rebuilt some time ago so I guess they didn't put them back right. Anyway, when I put everything back together, I put the cam bridges in the correct order, matching them with the numbers stamped on the head. Could this be part of the problem?

RedlineMan

Hey Clint;

Your upper bridges are upside down. The lower set are front-to-back 1-4, and the upper set are front-to-back 5-8, but the numbers should read upside down. Reference FSM Section 15-111, illustration photo 11804



In case you had not already noted this, the idea of the specificity of the line boring of these bridges, as well as the ones for the balance shafts, is no joke!

Imo000

I wish you posted this a little earlier. Now some things start to make sense There is a good chance that when the head was rebuild the cam towers (caps) were installed in the wrong order and all the caps were re machined in that order. If this was the case, the original numbering isn't accurate anymore. You need to find the order they were when the head was rebuild. Unless you remember the order they were on before you took it apart, you'll have to pull the cams out, install each cap one at a time and try to find the where each one belongs. Each cap will have a perfectly matching location where the two halves make a perfect circle that and no ridges at the mating point.

Do yo see what I mean? If not just let me know and I'll try to explain it in a different way.

Imo000

OR as John stated.. they could be just upside down. John....Good catch bro!

Clint's 944

Wow...I should have noticed that considering the FSM was laying beside the car the whole time...

Thanks Redline!

IMO000 - I'll try flipping them around and see what happens. If it still isn't working...I will try it your way!

Thanks Guys...your like a super deluxe factory service manual!

Imo000

Clint,

To be absolutely sure, you need to remove the cam or maybe even both cams to make sure the caps perfectly line up forming a circle without any edges. If you don't remove the cams and you miss a couple of caps, those caps will destroy the cams and themselves too. In that case you'll need a new head with cams. In this case you really need to go two steps back before you move forward. Don't worry, this happens to everyone every now and then.

RedlineMan

Hey;

Good catch? Indeed BTDT! Referencing how I know about the line boring... during the head job on the one I pictured, I somehow managed to get ONE of the upper caps on right side up. How the H#$@ I managed to get only one ... well... anyway, even with only one wrong, my intake cam would not turn even under many pounds of pressure. ONLY ONE CAP!

A normal head job would not involve disturbing the bearing lands at all, so if the cap are put back home it should be fine. Only if you mix up components from other heads, or have need of resurfacing one bearing land will you run into problems.
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I first learned about the line boring when I had to install balance shafts on an engine where they had been deleted. 86 Turbo. I had the upper bearing bridge and cover because they maintained the turbo oil feed through it, but the bottom set was discarded. I ended up hand fitting a set of bearings for the lower shaft because none of the extra caps I had would line up. It worked, but it took 5 times installing/checking/removing/sanding the bearing shells to get it to free up.

Clint's 944

I removed the cams and check all the cam bridges as you suggested. To be honest, putting them in sequence looked to be the best. So I put them back in, correctly this time and the cams rolled as they should! So, I figured why stop and finished getting everything back on and took it for a drive! Now, I haven't driven the car since the beginning of January but man was it sweet! It was pulling like crazy after 4k rpm! Maybe I forgot how it drove but...I'm telling you it is running alot better!

Thanks guys for your help...I thought it was a goner for a while.

Imo000

Excellent work!

Just one more question regarding this. Did you degree the cam when you were installing the cam gear? How did you know when to tighten the main camshaft bolt and the 3 small (6mm) bolts? As you probably noticed the cam gear has a fairly wide keyway and can have quiet a bit of adjustment.

Clint's 944

I etched a little mark by each hole before I removed the bolts. I figure it will be close enough until I can get them timed at the dealership.