Bob Onit

ZZ4 with steel roller camshaft - I'm having a problem getting the valves adjusted. I adjusted them per the procedure shown below

Spin the engine to TDC Compression stroke on #1. Adjust exhaust for 1,3,4,8 and intake of 1,2,5,7
Rotate one full turn (TDC Compression #6): adjust exhaust 2,5,6,7 and intake of 3,4,6,8

For some reason I believe that when I have the cylinder at TDC, the lifter to be adjusted is NOT on the very bottom of the lobe (fully closed) because after the adjustment (I tried 1/2 turn from zero lash the first time and then a whole turn the second time I adjusted them) because they are even noisier/looser then before I touched them.

Is it possible that the steel roller cam in the ZZ4 is somehow configured differently than other camshafts?

69vettester

Heres a common way..so as not to get confused where your at in the process. Its not the only way...

Disconnect Battery, Remove Park plugs , Do each cyl. one at a time. Example...Start with #1 Cylinder do intake & exhaust for #1 cylinder , then #3 Cylinder Int. & exh. , then #5, int. & exh. Until every cylinder is finished. This pattern is easiest. you watch each valve go through its cycles and by the second or third cylinder youll understand exactly where each lifter is on the cam.
Use a 1/2" drive and 5/8ths Socket on the Balancer Bolt to turn the engine clockwise.
To start ,just be confident that When a lifter goes just past TDC (just starts down) on the compression stroke, the Other lifter is on the Base Circle of the cam. Or 180 Deg. from the Cams Lobe . Ready to preload the lifter thats now on the Base circle. Initially set it to zero, that is when the pushrod first starts to resist. you can feel it with your fingers. Then Use the Manufacturers recomended turns to set the Preload. Usually its somewhere over 1/2 turn But you need to just do what the lifter vendor advises and you wont go wrong.

Make sense? if not, It should by the time your finished .

Bob Onit

Not exactly, unless I read it wrong.

I don't see how it's possible to adjust both the intake and exhaust valve on the same cylinder without rotating the crankshaft in between because the lifter must be on the base circle to have the valve fully closed. Correct?

Did you use this method on your 383 and if so, does it have a roller cam?
Thanks.

MotorHead

The intake and exhaust valve can be adjusted at TDC of the combustion stroke of that cylinder

1BAD80

I copied this from somewhere, and it's the way I adjust lifters.


Setting Valve Lash on Mechanical Cams

All the valves must be set individually and only when the lifter is properly located on the base circle of the lobe.
At this position the valve is closed and there is no lift taking place.
How will you know when the valve you are adjusting is in the proper position with the lifter on the base circle of the cam?
This can be accomplished by watching the movement of the valves.

1. When the engine is hot (at operating temperature) remove the valve covers and pick the cylinder that you are going to adjust.

2. Hand turn the engine in its normal direction of rotation while watching the exhaust valve on that particular cylinder. When the exhaust valve begins to open, stop and adjust that cylinder's intake valve. (Why? Because when the exhaust is just beginning to open, the intake lifter will be on the base circle of the lobe, so the intake is the one we can now adjust.)

3. Use a feeler gauge, set to the correct valve lash, and place it between the tip of the valve stem and rocker arm. Adjust until you arrive at the proper setting and lock the adjuster in place.

4. After the intake valve has been adjusted, continue to rotate the engine, watching that same intake valve. The intake valve will go to full lift and then begin to close. When the intake is almost closed, stop and adjust the exhaust valve on that particular cylinder. (Again, when we see the intake valve almost closed, we are sure that the exhaust lifter is on the base circle of the lobe.) Use the feeler gauge and follow the procedure described before in step 3.

5. Both valves on this cylinder are now adjusted, so move to your next cylinder and follow the same procedure again. In the future you may find shortcuts to this method, but it still remains the best way to do the job correctly.

Bob Onit

Wayne, is there a definite way to tell when it's on the combustion stroke other than feeling for slack in the pushrods?

Should this be performed with the engine warm or cold?
Thanks

MotorHead

When you rotate the motor to the 0 degree mark you will be at either #1 or #6 TDC on the compression stroke. To determine which one it is you look at the rockers of the other one.
If you are coming to the #1 compression stroke, then #6 will be in overlap, you can tell this because the exhaust valve will be closing and the intake will start to open, when they are equal ( on #6 ) you will be on TDC of the compression stroke on #1 and you can adjust both intake and exhaust valves on #1 This might sound a little confusing but try it and you will see it's not.

You can set all your valves on each cylinder this way by looking at their opposite \ corresponding cylinders. Or you can mark your balancer at 90 deg intervals or buy a cover that is marked at these intervals. Here is the way I look at the firing order to determine which set of valves are in overlap and which ones are at TDC of the compression stroke and can be adjusted.

1 8 4 3
6 5 7 2

For #1 you look at #6, #8 you look at the valves on #5 and so on

Warm engine for solid cams and it doesn't really matter on hydraulic cams

69vettester

I was trying to be complete but see I wasnt .

Yes , Same cyl. ,you turn the engine again to get the other lifter phased onto the base circle , set the Preload and lock it down ..use Kool nuts, they will never loosen. Then you Move to the next cylinder and do Both on that Cyl.

And yes I have a OE hydraulic Roller engine, uses the same size lifters as yours, But that doesnt matter, the Same procedure is used for adjusting all "Hydraulic" lifters.

GDaina

When both the intake and exhaust valves are closed, adjust the exhaust the moment the intake starts to open and adjust the intake the moment the exhaust starts to close. You can follow the firing order or you can start on either side. When one side is adjusted move to the other side.

This is the procedure for adjusting solid lifters. I'm not sure if the ZZ4 has hydraulic or solids.

Looks like I repeated what was posted above...pays to read before posting...

GDaina

Forget what I said...I got it backwards....

Bob Onit

Well, after adjusting the valves 4 times using 3 different methods they still aren't right.
So, this leaves me to try adjusting them while the engine is running.
The only tough part will be cutting out a center bolt valve cover for access to the adjusters.

I have never had an engine give me this much trouble from a simple valve adjustment... Maybe it's just because it's a roller cam... who knows.

Thanks very much for all the suggestions guys.

TLewis4095

For a solid roller GDaina has it right (just backwords as he states) and for a hydraulic just leave the valve cover off, cut a piece of cardboard to just fit in the lower lip of the head, start when warm...1 at a time, loosen until it ticks loud, tighten until it stops & then go 3/4 turn 1/4 at a time letting the lifter catch up between each quarter turn so it dosent kill. Then repeat until all are done. There will be some oil to clean up but should not be to bad.

Bob Onit

Well I cut out a stock center bolt valve cover with a die grinder. I cut out most everything but the mounts and the mounting gussets.
Warmed up the engine, Loosened the rockers until they started clicking loudly and very slowly tightened them until they got quiet then gave them another 1/2 turn. It's now very quiet and running great.
Didn't lose a drop of oil either.

Thanks again for all your help guys!

kdf1986

Did you loosen them all at the same time to start, or did you do one at a time, and go down the row for each cylinder head bank.

kdf

Bob Onit

I actually had to tighten some of them down a bit at first to get them quiet enough to be able to hear the one I was going to be working on.
Then I backed them off and adjusted them one at a time.
Started on the drivers side and then did the pass side.
Only had one cover off at a time.

kdf1986

Thanks for the reply. That seems like an easier way to do it if the car is already running.

kdf