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-   -   Cam Tower won't seat right (https://rennlist.com/forums/924-931-944-951-968-forum/187703-cam-tower-wont-seat-right.html)

Gear Dog 02-23-2005 04:21 PM

Cam Tower won't seat right
 
Ok made sure the engine was at TDC lined up the marks on the cam gear and the flywheel. I even went 2 revolutions on the flywheel. For the life of me I can't get the housing to sit flush.
I was thinking that the lifters have been out of the car for so long that they need to be coaxed a bit. But i don't have the heart to do that. Any advise would be greatly appreciated.

Mighty Shilling 02-23-2005 04:23 PM

Is the cam set at TDC?

Uranium-235 02-23-2005 04:34 PM

Its not going to sit flush because even at TDC some valves will need to be open, therefore the springs need to be compressed while you tighen the housing bolts. Rotate through the torque sequence, gently drawing the housing down and you should have no problems.

Danno 02-23-2005 04:35 PM

The cam-tower will not sit flush with the head because some of the cam-lobs are pushing on the lifters and valves. There is no rotation position anywhere that will have all the valves fully closed. That's why you have to slowly tighten the bolts in 3-4 passes a little at a time, to slowly push those valves open and not bind the lifters in their bores.

Before you install the cam-tower, inspect the holes that hold the locating dowels. Sometimes, impatient gorilla mechanics will zip down the cam-tower with air-tools and get things all crooked. Then they try to force the last couple of bolts down and straighten it up. But the mis-aligned cam-tower and dowels will end up digging sideways into the locating holes. Inspect these holes and make sure they're not deformed, ovalized or have raised edges. The raised edges will cause the cam-tower to touch down before the gasket is compressed enough. You'll end up with a leak as a result. So check the dowel holes in front & rear on both the cam-tower and head before you install.

Mighty Shilling 02-23-2005 04:37 PM

One thing that's not been stated yet, Ken, have you bolted em down and it wont' seat right, or are you thinking before you bolt it down?

If it's before being bolted down, the other two are right...if it's after, I'm afraid...

Gear Dog 02-23-2005 07:29 PM

No it is before, no bolts yet. It just didn't look right I just wanted to make sure something wasn't wrong before "helping"it seat.

Mighty Shilling 02-23-2005 07:41 PM

nope. nothin wrong then. just make sure you follow the pattern..

944Ecology 02-23-2005 07:50 PM

Here's a good tip...

Before you install the cam housing, rotate the crankshaft 90 degrees from tdc on #1. This way the pistons are all at the middle of their stroke, and well away from any valves.

Install the cam housing, then rotate the camshaft to TDC on #1.
Finally, rotate the crankshaft to TDC on #1.

If you do all of this by hand (it should move easily without a lot of leverage), you will be ensured to not be bending any valves while you are tightening down the cam housing.

Of course, it's only my opinion, I could be wrong.

gb

FRZ 08-20-2011 12:59 AM


Originally Posted by 944Ecology (Post 1945013)
Here's a good tip...

Before you install the cam housing, rotate the crankshaft 90 degrees from tdc on #1. This way the pistons are all at the middle of their stroke, and well away from any valves.

Install the cam housing, then rotate the camshaft to TDC on #1.
Finally, rotate the crankshaft to TDC on #1.

If you do all of this by hand (it should move easily without a lot of leverage), you will be ensured to not be bending any valves while you are tightening down the cam housing.

Of course, it's only my opinion, I could be wrong.

gb

Have you already made this method!?

Install the cam housing, then rotate the camshaft to TDC on #1.
Hard to rotate!?
Finally, rotate the crankshaft to TDC on #1.
Same question. I guess here if this is harder than normal there is a valve problem?

Mike C. 08-20-2011 10:23 AM

That is a good tip George... If you do it this way FRZ, once the cam housing is bolted tot he head, it will rotate easily until a lobe tries to open a valve. The valve spring will make it too hard to turn by hand so you will have to use a wrench to get past the spring. When rotating the crank to #1 TDC, never force it. (do this with spark plugs removed). The crank should rotate easily with a short rachet on the front pulley bolt. If you feel any sudden increase is resistance to turning, stop as something is wrong.

FRZ 08-20-2011 10:28 AM

Yes Mike Thanks for the spark plugs tips. This is what im gonna do finally, mixing this method:

0. Before I will rotate 90deg off the TDC flywheel mark to have the piston in the middle of the cylinder and be sure not bend any valve
1. Align the cam mark, torque down the cam housing;
2. The mark will maybe rotate a little, so I will put the cam belt on and then align the cam mark correctly with the help of the crankshaft pulley;
3. Remove the cam belt;
4. Rotate the crankshaft back to TDC (slowly to not bent any valve if something wrong);
5. Reinstall cam belt and talam!


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