jwasbury

Howdy folks, I've been working on my valves today too. Used the backside method. I found that the difference between "go" and "no-go" on the .003 feeler was an incredibly small turn of the adjuster screw. With this method, you're trying to hit between .0025 and .003. Its a difference of only .0005! I'm not even sure what that is...5 ten-thousanths of an inch? That is the equivalent of a gnat's eyelash. I've done the valve lash on many a motorcycle, but never have I dealt with such exacting tolerances. I am now half done with my full tune up...valve adj, fresh plugs, wires, cap and rotor. I'll deal with the other side tomorrow (maybe).

Oshin11

It may be 5 ten thousandths of an inch on the back side but its 1.4 times that at the elephant foot. Also remember that the nominal spec is not right in between .0025 and .003...its much closer to .003......people overlook this more subtle concept.

old man neri

Okie. So I am trying a new image hosting site so hopefully it works. And I was wrong!, turns out the sticker is a silver type colour, not gold as I had previously mentioned.


Here is the sticker. I noticed it is an emissions sticker so I don't know if that effects anything.
Edit: Thinking about this it probably the spec as to how far out of adjustment it can go before it causes emissions problems. Just a guess.



Close up of the bottom left corner.





And for you Doug, what I woke up to this morning, no cool vegetation. Just a bitter wind, a lot of ice, and a C-130 taking off in the distance.

Amber Gramps

don't worry old man, we are plotting our next you tube I think we are going to call it "The Bray Family Tropical Adventure" Shot on location right here at home. As soon as the DSL is back up tonight and Santa is well on his way we will post it for all to see. you can look too.

KC911

I haven't read all of this thread, but methinks you guys may be "overthinking" and obsessing about this a bit too much ! I do my valve adjustments the "traditional" way, and I'd bet that most pros have been doing it that way for a long, LONG time. Trust me, it isn't that difficult, and it would appear that some are making it more of a PITA than it needs to be. The first time I did mine, I went around twice (for good measure and just to double check), and she runs like a scalded dog...and that's a good thing!

911vet

I went to NAPA and bought a set of feeler gauges. I'm going to try to make a new 0.004" tip for my Pelican tool so I can work on the car tomorrow (yes, that's how I'm spending my Christmas).

I'm sticking to the traditional method for this first job.

I want to double check something. Has anyone else (besides Oshin) experienced the elephant feet sticking to the valve stem? When I started each valve, I had no discernable gap. Couldn't get a feeler in there at all. Even after wiggling it. I only got a gap after loosening the adjustment screw and breaking it free.

So is the e-foot forming a suction fit on the valve stem and actually lifting the rocker arm off the cam?

I assume it's a function of the e-foot having a concave surface (because it's worn?) and acting like a suction cup with the oil forming an airtight seal.

I've not read anything about this on any threads or tech articles. Just double checking myself.

Thanks.

Porsche8777

Just finished mine for the first time. I had to wiggle the rockers to break the foot loose from the valve. I had two valves that had to be adjusted, the rest checke OK.

Word of caution about the feeler gauge. I had some from Paragon Products and also some from Porsche. The ones from Paragon were brittle and broke easily. Glad it broke on a passenger side exhaust valve I could see. The ones from Porsche would bend but I never had one break.

911vet

Thanks for the re-assurance. It was an unexpected finding.

So, do you feel confident in your settings? Just wondering how you judged the "feel" of the feeler gauge. I had a friend helping and he seemed to think we were right. But when I double checked using the backside method, I was loose on all of them.

And talking to 964 guy who adjusts valves for a living... sounds like he snugs that thing down tighter than I did.

Despite my frustration regarding the subjective nature of the feeler gauge, I have to admit this is fun

imcarthur

That's 'cause you're tinkering right in the belly of the beast.

Glad it is going well. I also found that you had to loosen to get the feeler in. Well, I did on my 1st two attempts. Even with the backside, sometimes you try a dozen times to get the feeler in & then all of a sudden it zooms in & you haven't changed anything. Stiction of the oil? Phase of the moon?

Ian

911vet

It is winter solstace. Hmmm...

Oshin11

Shannon: It is not the suction between the elephant foot that pushed the valve out. The rocker arm pushes the valve in, however the valve is spring loaded so it is a spring that pops the valve back out.


EDIT: I was really peeved today because I called performance products in Van Nuys, they said they had valve adjustment screws and that they were open until 3PM. I drove all the way there and got there at 1:30PM to find NOBODY there. I was so pissed off.

911vet

I realize that under normal operating conditions there would be no such suction between the elephant foot and the valve stem. (i.e. I know that it doesn't pull the valve closed). I was just trying to figure out what was happening in the cold engine.

Sorry to hear about Performance Products. I've dealt with them via internet and phone and I have to admit I've had better luck with Pelican.

ne ohio 911

Put some oil on the feeler gauge and slightly twist it in. It should be tight, but it will go in. Takes some time and practice. I made the mistake of loosening them all the first time I did it. When I buttoned everything up I discovered most were too loose. I left them loose out of paranoia. Too loose is OK, too tight is bad. Second time was better. If you have to go back in for a second go around, you can do one side at a time. You will only lose a quart or two of oil out of the bottom covers. Just make sure that you turn the pulley 240 degrees for each valve instead of 120.

Droops83

It's not really possible to adjust 911 valves too tight. If the clearance is too tight, you won't be able to get the feeler blade out (though as we all know, if it were possible to get them too tight, that would be bad!). You do not want them too loose, the rocker and the end of the valve stem can get beat up that way, plus the noise. A lot of people adjust them too loose; you should be able to slip the blade in and out but it should be pretty snug. What can throw you off is if the "elephants feet" are worn or if the blade on the feeler gauge is slightly curved from use, it can make the clearance feel tighter than it really is. I always move the blade up and down, side to side over the whole surface of the blade while it is in between the rocker and valve stem so I can get a good feel of what the clearance really is.

For any newbies out there, it takes practice, you need to get a feel for it. I work on these things every day and I can adjust the valves in 5 mins or less if I have to, but if you are a DIYer only adjusting the valves on your own car every 15k miles, you do not get the opportunity to adjust them that often. While it is apart, adjust the valves several times in a row to get the feel for it. Hell, do it 20 times if you need to.

BTW get Wrightwood Racing graphite valve cover gaskets if you can, most of the rest are crap.

911vet

I've been thinking about this very thing. I keep hearing "better too loose than too tight because too tight can damage the engine." Obviously, if you made them so tight the valve could not close, that would be a problem. Otherwise, why does it matter if it opens a little wider? It's not enough to contact the piston, is it? Even if you were too tight by 0.002" or even 0.003" is that enough to hit the piston? What's the harm when they are too tight?

OK, you lost me on this. How does the rocker get beat up by it being too loose? I don't see how the elephant foot or valve stem do either?

You are right on target with this statement. That's exactly what I found. When my feeler blade got jabberwockied, I couldn't tell anything. All I could go by was how hard or easy it was to slip it in. I started paying more attention to that than how the gauge moved once it was in there. I felt the adjustment was right if I perceived the blade was in contact with both the stem and the e-foot (i.e. being scraped slightly top and bottom).

I think my next one will go much better. I'm going to seal it back up and find out what havoc I have caused.

Let's see. I've spent 13 hours on the project so far, still have about 2 hrs to go. Hmmm.... I guess my first dog spay surgery took 3 hours. Now it takes about 30 minutes. So, I have hope for me and valves!

Now you tell me!