Valve Adjustment

[bazar01]

Today I finally decided I will adjust the valves, change valve cover gaskets, change spark plugs and do an oil change.

It's now on the lift.


Passenger side exhaust valve cover off.


Driver side:


Still need to remove engine tins. That's ok, I will take my time.

Question.
Can I use the backside method using 2.5 thou "GO" and 3 thou "NO GO" feeler gauges on the 964?
I tried the 4 thou between the rocker and valve stem, it seems tough to get in between. It's bending/damaging the gauge mat'l.

[bazar01]

Well, I got the engine sheet metal off on both sides and feeler gauged the current clearances. I did not see any loose stud nuts. Am I lucky?

Is it normal for the clearance to go on the high side with mileage? Most are on the 0.003" to 0.004" using the backside method. I thought the valve clearance will decrease with mileage.
Shall i just button it up?

Driver Side:


Pass Side:

[Newsboy]

If it's .003, it did decrease slightly. I would check again and use feeler gauge method to verify
.004 before buttoning it back up.

[bazar01]

I am doing the back side method where:.
0.0025" feeler gauge should go in between camshaft and rocker.
0.003" feeler gauge should not go in.

When I gauged it, the 0.003" feeler gauge went in on majority and on two instances the 0.004" went in.

I will adjust it before I button it up to be safe.

[rattlsnak]

Interesting, ive been doing this many years and have never heard of the "backside" method.

That being said, you wont see much movement with 3.6 like you will with an older, say 2.2 or such.

[bazar01]

Here is the before and after adjustments. Most valves were on the looser side.
I followed this tech article on this board. Pelican Technical Article: 911 Valve Adjustment - The Backside Method

[bazar01]

Originally Posted by rattlsnak

Interesting, ive been doing this many years and have never heard of the "backside" method.

That being said, you wont see much movement with 3.6 like you will with an older, say 2.2 or such.

I've never heard of it before until I read the article. It was a lot easier.

Example of the method used for cylinder #3 intake.


Example of the method used for cylinder #3 exhaust.


Gauges I used:
0,0025"
0.003"
0.004"

[bazar01]

Another tip to do the driver side valves all at the same time is to rotate the crank 240 degrees at a time from Z1. This keeps me from going back and forth between the driver and passenger side if I follow the 1-6-2-4-3-5 order. Then do the passenger side next.

This is the Z1 mark on the pulley with the distributor rotor pointing to the triangle on the body.

[rattlsnak]

Well there ya go. Ill have to give that a try next time!!

[bazar01]

I'm happy I did the backside method. I bent all of my three 0.004" gauges on the special tool. Went to the nearest auto parts store and got a $6 set of feeler gauge that has the 2.5, 3 and 4 thou feeler gauges.

I targeted 3 thousandths of an inch using the backside method and this translated to 1.4 x 0.003" = 0.0042" which is very close to the 0.004" specs.
The decal states that the valve lash is 0.004" +/- 0.002" so I am still good.

Time to get the engine tin painted due to rusted surfaces and it's good to go.

[bazar01]

Does anybody know the torque value on the jam nut for the adjusting screw?
I am getting ready to button it all up and just wanted to make sure the jam nuts will not back out.
Thanks.

[bazar01]

The adjusting screw is M8, so I will just follow the minimum torque value which is 14 ft-lbs.
M8 bolts require 14 - 21 ft-lbs of torque.

[Pete000]

Nice work, I did this job a few months ago and was a bit intimidated until I got into it. I also used the back side method. I had no luck even getting the feeler in between the valve and rocker. Back side is way easier. Some folks do both.

Tip: take the feelers out of the holder and put a zip tie on each one to act as a loop to hold on to when sliding it in and out. I saw a pro doing this once.

I had that feeler Gage holder come unscrewed and the nut nearly dropped into the engine ! Heart Attack time ! I read this could happen and it does !

[bazar01]

Originally Posted by Pete000

Nice work, I did this job a few months ago and was a bit intimidated until I got into it. I also used the back side method. I had no luck even getting the feeler in between the valve and rocker. Back side is way easier. Some folks do both.

Tip: take the feelers out of the holder and put a zip tie on each one to act as a loop to hold on to when sliding it in and out. I saw a pro doing this once.

I had that feeler Gage holder come unscrewed and the nut nearly dropped into the engine ! Heart Attack time ! I read this could happen and it does !

Hi Pete, I followed your tip and went ahead and removed the feeler gauges and tied them individually on a zip tie. Checked the clearances for the last time and they all checked out good.
I also did a compression test before putting everything back together.

Compression at 105k miles on 4 engine rotations (cold):



Bottom of engine. No oil leaks.



Filled it up with oil. Cranked and it started on first try. A lot smoother and quieter than before the adjustment. Quite intimidating at first but once you get the feel of the gap using the backside method, it's actually very simple.