1st time valve adjustment questions

[911dean]

The car is an '84 3.2. I don't want to do this twice.
1. I can't find a z1 mark just notches on the pulley. Is there a z1?
2. Was recommended to skip #1 and go to #6. Is #1 left rear cylinder? if so seems very easy to get to. Why skip to #6 if right front cylinder?
3. Is 120 degrees first notch I come to after z1 tdc mark?
4. Valves I've checked seem tighter than .004.
Thanks for all the help in advance.
Dean

[911dean]

I think I have it figured out.
Dean

[Tidybuoy]

I thought I didn't have the z1 mark on my pully but it showed up with a magnifying glass. It's really tiny and very hard to see (especially at an angle).

On my '74 2.7, the Z1 mark is the RIGHT of the two notches in the pully. This is exactly opposite of what is published in the 101 Projects book. I didn't discover this until I was finished adjusting all valves. Fortunately, this only affected #1 & #6 cylinders so it was not too bad to re-check those two.

After I finished adjusting all valves, I searched some of my various Porsche books (looking for valve cover torque) and that is when I found a diagram with the Z1 mark on the RIGHT of the two notches. This caused me great concern since the 101 Porjects book show it as the LEFT of the two notches. Which one was right? Also, when initially adjusting my #1 & #6 using the LEFT notch, those valves were initially very tight.

After this, I went and got a magnifying glass to see if I had any marks at all on my pully and this is when I found the Z1 to be the RIGHT notch.

I don't know if it is different for various engines but I was very dissapointed in the 101 Projects book as it did not address this. In addition, the 101 Book does not address valve cover torques and this took me another hour to find this out (it's 6-8 lbs per foot).

Hopefully, some of the other experts will chime in on this topic.

Vern

[manbridge 74]

Are you sure?

Not near my 911, but if I recall it is Z1(TDC) then 5 degree ATDC mark to the left if one remembers that crank turns clockwise looking at pulley.

Can't remember 101 book being wrong on that but its possible.

[Flat6pac]

The is both, right and left of z1 marks depending on the pulley and tuning application.
Bruce

[theFONZ]

If you take the distributor cap off, you will see a mark at about 4oclock as you are looking at it. That is cyl 1. Make sure the rotor is pointing at that when you are on Z1.

I made that mistake my first valve adjustment, but found the problem when I was going back through verifying everything.

[Targalid]

The other thing you can do to check is the position of the cam lobes. They should both be pointing out away from the valves when you make the adjustment. This is a quick double check. If you are not on the flats you are on the wrong cylinder or you have not turned the crankshaft pulley 120 degrees.

[Tidybuoy]

Originally Posted by manbridge 74

Are you sure?

Not near my 911, but if I recall it is Z1(TDC) then 5 degree ATDC mark to the left if one remembers that crank turns clockwise looking at pulley.

Can't remember 101 book being wrong on that but its possible.

Now you can understand my frustration. Below are two pictures; the 1st is from my Porsche Tech & Spec Manual, purchased from Pelican and the 2nd is from the 101 Projects book, purchased from Pelican. The pictures show exact opposite for the Z1 mark. My car matches the Tech & Spec book - not the 101 projects book.

From the Porsche Tech & Spec Manual: Z1 is LEFT of 2 Notches



From the 101 Projects Book: Z1 is RIGHT of 2 Notches

[theFONZ]

My SC has the same marks as the 101 projects book.

[2.70Racer]

The intake and exhaust valves are closed for over 100 degrees before and after the Z-1 mark on the crank pulley. Therefore it really doesn't matter which mark you are on. Just be certain you are on the compression stroke.

[Walter_Middie]

This has been discussed on here before. The picture from the 101 book is an SC pulley. Flat6pac is correct as you can see from the few examples given here, different engines had different pulley markings. No mystery – you just have to get the correct one for your car.

Targalid is correct in that the exact placement of the pulley is not critical – just make sure the cam lobes are pointing away from the rocker arms.

911 Dean – this might help