jmattiko

Hi All,

I've got my motor back together and have a question on how to set cam timing.

I own both of Wanye D's and Adrian's books and in Wayne's there is a proceedue for setting cam timing but neither of his 2 writ up's seems correct for the 964. Obviously his book only covers up to 1989.

In his write up for a motronic engine, it indicates that I should hit my desired valve movement before I've turned the crank 360 from TDC #1. However, I hit 1.26mm only after the crank has moved about 380 degrees. What's up?

In his write up for high lift cams, it indicate that one should turn the crank exactly 360 degrees and then remove the pin and dial in the valve movement buy turning the cam seperate of the crank.

The problem with both of these proceedues is that our 964 cams do not have the nice flat spots on the ends to grab and turn.

Can somebody help clarify the correct proceedue for a 964 cam setting?



Thanks and Best Regards,

Joe.

axl911

Hey Joe,

I am in the exact spot where you are. Trying to time the cam!

Did you have the dot pointed straight up? Did you have the dial zeroed correctly? Mine took exactly 360 degrees to get 1.26.

I am now trying to do #4, but can't figure it out.

---
anthony

dutchcrunch

joe, do you have the proper tension on chains?

axl911

Here is the boiled down procedure I used to time my cam over the weekend. It's ain't that hard. The more you can get the dots on the cam pointed as straight up, the more accurate your timing will be and no adjustment is needed.

To set timing for Cylinder 1.
1. Rotate the pulley so Z1 mark is lined up with the case parting line.
2. Install cylinder 1 intake rocker.
3. Make sure both cams have the dots pointed straight UP. Draw a line from the dot through the center of the cam will make it easier to see the dot is pointed straight up.
4. Put the pin into the cam sprocket where the holes line up. Do this for both sides. You can put the cam sprocket bolt in or not. Leaving it out makes it easier to see how the dot moves.
5. Adjust the cylinder #1 intake valve clearance to .1mm like you normally do in valve adjustment.
6. Mount your dial gauge on cylinder #1 intake. And set it to zero value.
7. Rotate the crank pulley clockwise almost 360 degrees. As you approach the Z1 again you will notice the dial begin to move.
8. Continue to rotate clockwise until the gauge moved 1.26mm or .05 inch. STOP.
9. Is the Z1 mark lined up with the case parting line? If not, use a small screw to remove the pin on the left side cam. Rotate the crank pulley until the Z1 mark is lined up with the case parting line.
10. Now put the pin back into the cam sprocket where the holes line up.
11. Double check by rotating the crank pulley 720 degrees. By the time the Z1 comes around for the second time, when the Z1 is lined up with the crank pulley, your dial gauge should have moved 1.26mm or .05 inch.
12. You are done with cylinder #1. Don’t move anything.
13. If it takes more than 360 degrees to get the dial gauge to move 1.26mm, then you either don’t have the cam dot pointed straight up at the beginning or you did not adjust your cylinder 1 valve clearance properly.

Now to set timing for Cylinder 4.
1. After completing the last step in setting timing for cylinder 1, the dot on the right cam should be pointed straight DOWN.
2. Install cylinder 4 intake rocker.
3. Adjust the cylinder 4 intake valve clearance to .1mm like you normally do in valve adjustment.
4. Mount your dial gauge on cylinder 4 intake. And set it to zero value.
5. Rotate the crank pulley clockwise almost 360 degrees. As you approach the Z1 again you will notice the dial begin to move.
6. Continue to rotate clockwise until the gauge moved 1.26mm or .05 inch. STOP.
7. Is the Z1 mark lined up with the case parting line? If not, use a small screw to remove the pin on the RIGHT side cam. Rotate the crank pulley until the Z1 mark is lined up with the case parting line.
8. Put the pin back into the cam sprocket where the holes line up.
9. Double check by rotating the crank pulley 720 degrees. By the time the Z1 comes around for the second time, when the Z1 is lined up with the crank pulley, your dial gauge should have moved 1.26mm or .05 inch.
10. You are done!!!
11. If it takes more than 360 degrees to get the dial gauge to move 1.26mm, then you either don’t have the cam dot pointed straight up at the beginning or you did not adjust your cylinder 4 valve properly.

---anthony

Dave R.

Anthony,
thanks for posting the procedure

axl911

Two things to add to my procedure.

1. Install some sort of tensioner device on the chain when you do your cam timing. I used a generic steering wheel puller.

2. Always rotate clockwise. Always.

Geoffrey

The only thing I'd add is that I use a degree wheel and a piston stop to find true TDC. Sometimes the Z1 mark is off slightly and this will affect your cam timing.