How do I know where to turn engine for each cylinder?

[Trakrat]

OK... I'm curious how EXACT you need to be at each cylinder when adjusting valves...
I had the engine at TDC... based on the marks. Which means that I can now adjust cylinder #1 valve clearance.

So my question is... how do I know when I've turned it to the next cylinder #6?
I could keep putting the distributor cap on... getting an 'idea' where the rotor is and guessing it's at the next cylinder, but it's just a guess.

Is there a more accurate way, or something I should 'feel' for when turning the engine to know when it reaches each cylinder?

[rwest]

Well, all you really need to do is make sure the rocker arm pad is not on the lobe.

If you want to do it systematically, you make sure the rotor is at the firing point for cylinder #1 and crank pulley is at Z1, then you adjust #1, next you rotate the engine clockwise- always clockwise 120 degrees- should be a mark on the pulley face. That would be cylinder #6; following the firing order every 120 degrees will be the firing point for a cylinder.

4 stroke engine, every two turns of the crank is a firing stroke 6 cylinder equals 3 firings per revolution 3 divide by 360 equals 120 degrees.

[ginot912]

there are timing marks on pulley that you line up to bottom mark on fan housing.
1-6-2-4-3-5 is firing order

[Dr J]

Use the crank pulley. There is a mark for zero degrees usually marked with the letter Z. Since the engine rotates twice for each power pulse you check the distributor to be at the #1 spark plug position and the crank pulley at Z1 aligned with the parting line in the center of the engine. You should see it underneath the alternator. That is what gives you the precise position. The pulley likely has marks at 120 degrees. So engine at Z1 and distributer aligned to #1 is cylinder 1 at TDC. Rotate via the alternator pulley or using your favorite method till you see the first 120 degree mark. You are now at cylinder six. Go to the second 120 degree mark and you are at TDC for cylinder 2. Rotate back to Z1 and you are now at cylinder 4, and so on...

[proporsche]

trakrat.i would suggest to get some books and do a little reading before you start doing any valve adjustments;-)

Ivan

[rwest]

I'll add that at least on my 77 the 120 degree marks were not notched at the edge like the timing marks, but just on the face and I had to look carefully to not miss them.

[Trakrat]

Originally Posted by rwest

Well, all you really need to do is make sure the rocker arm pad is not on the lobe.

If you want to do it systematically, you make sure the rotor is at the firing point for cylinder #1 and crank pulley is at Z1, then you adjust #1, next you rotate the engine clockwise- always clockwise 120 degrees- should be a mark on the pulley face. That would be cylinder #6; following the firing order every 120 degrees will be the firing point for a cylinder.

4 stroke engine, every two turns of the crank is a firing stroke 6 cylinder equals 3 firings per revolution 3 divide by 360 equals 120 degrees.

soo... when I originally set it to TDC... I rotated it counter-clockwise... as the rotor was probably just past cylinder 6 and thought it would be faster to get to TDC.
Of course looking at more articles and such, I read that you should always go clockwise.
Anything I should be concerned about? Or just make sure I go clockwise from here on out??

[Trakrat]

Originally Posted by proporsche

trakrat.i would suggest to get some books and do a little reading before you start doing any valve adjustments;-)

Ivan

Thanks Ivan... I've been reading (Bentley service manual, all of Wayne's books, as well as Bruce Anderson's) and watching you tube videos, and doing searches on this forum for the past 3 months. At some point I just need to start at it.

[rwest]

Originally Posted by Trakrat

soo... when I originally set it to TDC... I rotated it counter-clockwise... as the rotor was probably just past cylinder 6 and thought it would be faster to get to TDC.
Of course looking at more articles and such, I read that you should always go clockwise.
Anything I should be concerned about? Or just make sure I go clockwise from here on out??

Hopefully someone more knowledgeable will jump in here, but I believe the issue going ccw is that the chains can go slack and jump timing. I don't think it automatically happens, just a risk. Don't take my word on it and also don't start it until you confirm the likelihood of something going wrong.

[Rawknees'Turbo]

Rut(ager) is correct - takes a lot more than a counter clockwise nuge to create a problem.

Trakrat, use the crank pulley timing marks (make them easier to see by neatly putting a dab of paint on them) in conjunction with the distributor rotor position to help orient yourself.

No need to keep putting the distributor cap back on - can take a pic with your phone of anything there that you want to look at, or just hold the cap nearby.

Then verify that both intake and exhaust rockers are slack for the piston that you are attempting to place at TDC of the compression stroke.

Also, it doesn't hurt to practice this before actually touching the valve lash (go though the entire TDC procedure for each cylinder a time or two until you are comfortable).

[Trakrat]

Originally Posted by Rawknees'Turbo

Also, it doesn't hurt to practice this before actually touching the valve lash (go though the entire TDC procedure for each cylinder a time or two until you are comfortable).

I did this a few times... interesting observation though is that cylinder 2 and 3 leaked a small amount of oil (maybe 3-4 drops total) through the exhaust valve (reason I know this is that my headers are currently off).

[Bob Kontak]

Originally Posted by Trakrat

I did this a few times... interesting observation though is that cylinder 2 and 3 leaked a small amount of oil (maybe 3-4 drops total) through the exhaust valve (reason I know this is that my headers are currently off).

Focus on the valve adjustment.

However, I think I remember Bruce Anderson saying push the valve stem sideways with a screwdriver. Look for slop. If you see sideways movement, change your focus, but you have a little time.

Just saying would like to see you drive your car this summer even if they are tired.

[Bob Kontak]

Originally Posted by Trakrat

Thanks Ivan... I've been reading (Bentley service manual, all of Wayne's books, as well as Bruce Anderson's) and watching you tube videos, and doing searches on this forum for the past 3 months. At some point I just need to start at it.

Once you get the timing business down and get your hands in there to adjust, you will want to hang yourself for trying this.

By the third set of valves you will stop weeping.

By the time you are done you will find the last two sets boring.

Rotate crank 720 on each set as you go for recheck.

[Canada Kev]

Originally Posted by Bob Kontak

Once you get the timing business down and get your hands in there to adjust, you will want to hang yourself for trying this.

By the third set of valves you will stop weeping.

By the time you are done you will find the last two sets boring.

Rotate crank 720 on each set as you go for recheck.

Yep, Bob's bang on. My first time I wanted to lash out irrationally at the beginning. By the end, I was thinking, "Huh, well, that's not so bad. Next time I could probably do that in three or four hours."

As it was, it took me an entire Saturday, but I did a bunch of other maintenance stuff, too. I gained experience and the always welcome confidence to try more difficult tasks. And even being my first time, I probably saved money. On jobs like this I often factor in my own time, like paying myself. Now, I make money on every valve adjust I do.

[Trakrat]

Thanks all... I've read some conflicting statements about spark plug removal.
I have all new spark plugs (copper core) and new Magnacore wires I'm putting on the car after I complete the valve adjustment.

The conflict is whether to remove all the spark plugs first... then remove valve covers and do valve adjustment??
Or to keep the old spark plugs in while doing valve adjustment, then replacing the spark plugs AFTER the valve adjustment is complete.

Anyone have any experience between the two???
My thought was that I don't want junk falling in the spark plug holes, so I should keep the old ones in and then replace them after completing the valve adjustments.

[Canada Kev]

It is my opinion that you are correct in your thinking regarding plugs. But for the wrong reason.

It has nothing to do with junk falling in the plug holes. When you remove the plugs you might dislodge some carbon or other build up and and it might jam under an open valve and mess up your valve adjustment. It doesn't hurt to leave them in and could potentially save an inaccurate valve adjust if you took them out before. Better safe, I think, with no potential downsides to it.

Plus, it's nice to have the plug wires in place to identify which cylinder fires next if someone mixed them all up in some past life of the car. You could follow the wires from the distributor to the plugs. If its your first time, it's best to keep things simple and do one thing at a time.

[mo-mon]

Trakrat,

A few threads for your viewing pleasure

Valve adjustment gone bad

Read the esteemed Grady Clay's RIP posts.

performancedevelopments.com – Engine Design

Z1 (TDC) location on '87 Carrera

IMHO, valve adjustment is a "rite of passage" for the 911 owner. It will test you but reward you after. Did my '88 yesterday & I have to re-adjust #6 intake. Slight valve chatter.

[Trakrat]

Thanks all... My problem was that there is a notch about 20 degrees from the TDC notch that kept throwing me off.
I also don't have a Z1 stamp anywhere that I can see which made it confusing to know if I was really at 120 degrees from where I was.

Fortunately the distributor rotor matched up with where TDC was.
Apparently TDC is the same notch for cylinder 1 and cylinder 4.... which I didn't know at first (and didn't want to assume it was, due to the other notch).

I think I have everything adjusted correctly. Now to put everything back together and see how she does.

[Jesse16]

FYI, I was horribly herky jerky my first time doing my 87. The notches on the pulley didn't seem right (but they were actually) and I didn't want to screw anything up. All the suggestions above about taking photos of the wires from the dist. cap etc. are great things to do. Also trace them yourself and trust the cylinder numbers and etc.. Sounds like you have it worked out now. I did do one adjust where another mechanic type told me he could hear them clacking so I was too loose.
Then I had to go back under and check finding one or two "maybe" too loose. Not the worst thing to be .001" too loose.