How to adjust Valves

[jeffporsche]

My pocket is a little bit tired from being charged $375 per valve adjustment. I am going to jack up the car and try it myself. Any suggestions on how to do it properly?

[cary]

Your wish is my command. Thanks to Wayne and his staff.

Step by step instructions.

http://www.pelicanparts.com/techarticles/911_valve_adjust/911_valve_adjust.htm

Good Luck

[jeffporsche]

Now I can go under the beast and hope that the oil will not drip in my eyes.

Thank you,

Jeff Caron

[bell]

don't forget that you'll need the valve cover gasket set (comes with new lock nuts/gaskets), i did my first valve adjust recently and as long as you have quality tools (don't want to damage the aluminum ) and are somewhat mechanically inclined, it should be no sweat. just a note, i made myself a cheat sheet of the sequence and marked every step i took, it made keeping track pretty easy if you stop for a beer


p.s.........check your email

p.s.s.......you will also find that the info provided by pelican
is priceless.

[marcesq]

Change the oil at the same time or you will be contributing to the Superfund cleanup program

Just easier not to deal with the oil that flows from the return tubes to the lower cam towers.

My 1 cent.

[bell]

also....i used aluminum foil to wrap my cat so oil wouldn't drip on it, someone here recomended that and it worked great, sorry but i don't remember who suggested that
yes change your oil at the same time, you need to drain it anyway to pull the covers.

[JDaniel]

You don't need to drain the oil if you only jack up one side at a time... but it's probably easier to follow the Pelican article the first time.

[bell]

ok i didn't know that do you even need to tilt the car for the top covers? i did realize when i did mine that not a lot of oil came out.

[JDaniel]

Correct. Lift 1 side at a time. It's pretty easy, and I've rarely had more than a drop or two of oil... of course "normally" you'd just drain the oil, swap filters, and do all the valves at the same time. This falls into the category of valve adjustment 301 (for the semi-experienced). I also like Superman's idea of leaving the car in gear and turning the rear wheel to move the crankshaft

[zuffenhausen]

Only thing I'll add is to err on the side of loose. The consequences of a loosely-adjusted valve are simply a bit of noise, an almost negligible loss of power, and slightly accelerated wear of the foot and/or valve stem. The consquence of extended running with a valve adjusted too tight is a burned valve. Not good.

By the way, at the engine school at G&W Motorsports we were taught that the feeler gauge should drag lightly. If it takes more than just your fingertips to slide the gauge around and it feels like a magnet, it's probably too tight.

-zuff

[Bill Douglas]

You guys are quite inspiring. I've always been a bit of a scaredy cat when it comes to valve adjustments, but this time I'll try it myself.

I've actually had the valve adjustment tool from Wayne for a few years but just not used it. And Warrens tip: put a few drops of epoxy on the little nuts that hold the blade on your feeler guage - you don't want one to fall inside your engine.

[ChrisBennet]

Originally posted by Bill Douglas
.. And Warrens tip: put a few drops of epoxy on the little nuts that hold the blade on your feeler guage - you don't want one to fall inside your engine.

Bill,
You must have meant Loctite, not epoxy. You'll need to be able to replace the blades at some point.

zuffenhousen,
I guess I'm doing mine too tight. I tighten mine as tight as possible and still get the feeler guage in.
-Chris

[zuffenhausen]

Originally posted by ChrisBennet

zuffenhousen,
I guess I'm doing mine too tight. I tighten mine as tight as possible and still get the feeler guage in.
-Chris

Yeah, Chris, that's probably too tight. If that were the correct setting it would be much easier to adjust the valves simply because you could loosen the adjuster, put the feeler gauge in, tighten the adjuster all the way down on the gauge, tighten the locknut, and then pull out the gauge with all your might! Anyway, if you set them like I said such that the feeler gauge barely drags, they'll still be quiet once the car warms up.

-zuff

[ChrisBennet]

The gap clearance windens as the engine heats up so it shouldn't be a problem anyway.
-Chris

[Wayne 962]

If you spread just a thin layer of clean motor on the feeler gauge, it makes the process go quite a bit easier...

-Wayne

[zuffenhausen]

Originally posted by ChrisBennet
The gap clearance windens as the engine heats up so it shouldn't be a problem anyway.
-Chris

Actually, the gap decreases as the engine warms up and the metal parts expand. That's why there's an adjustment gap in the first place. The goal is for there to be no gap between the foot and the valve stem when the engine is hot. If expansion wasn't an issue, you could just touch the foot to the valve stem with no gap and let that be it. That's also why even a car with properly adjusted valves may have ticking valves when cold, and then the valvetrain gets quiet when it's up to temp.

-zuff

[ChrisBennet]

Originally posted by zuffenhausen


Actually, the gap decreases as the engine warms up and the metal parts expand. That's why there's an adjustment gap in the first place. The goal is for there to be no gap between the foot and the valve stem when the engine is hot. If expansion wasn't an issue, you could just touch the foot to the valve stem with no gap and let that be it. That's also why even a car with properly adjusted valves may have ticking valves when cold, and then the valvetrain gets quiet when it's up to temp.

-zuff

While what you say certainly makes sense to someone who hasn't actually measured it I offer this from the Rennlist 911 list achives:

Date: Mon, 05 Nov 2001 18:25:10 -0700

Author: "Walter Fricke"

Subject: Re: CW: Valve Adjustments

Body: DC

Here, for what it may be worth, is my experience and theory:

I used to worry over this. Then I discovered that as the engine heats up the valve lash gets larger, so you are less likely to have anything bad happen like burning a valve or seat, or hitting a piston with a valve. And I decided that I could more accurately feel when I could just barely get the tool in there than I could sense any other "feel," and that having them all the same was probably better than having them somewhat different, and that having them a bit tight might even give me a bit more power through longer duration. So I am at the force it through end of the spectrum (hard on the feeler gauge, though).

I'd be careful if my system was to loosen the adjustment, insert valve, tighten adjustment, and then see how hard it was to get the feeler gauge out. This is fine to start with, but you want to see if you can get the gauge back in by wiggling it. Usually the two are about the same, but it is possible to get the gauge out, but not get it back in.

But I have also concluded that none of this is likely to matter much. If you can get the feeler gauge through at all you are not too tight (only way you might cause real trouble), and if you are loose by a thousandth or two at most you might possibly have a bit more valve noise at idle. Only if you ignored something so loose you had zero drag and could rock the rocker with the gauge in place would I think you might end up with a real problem. (For instance, my race cam maker says I should use 0.008 for lash on it, which I have dutifully done since they say so, and things wear fine considering the use and don't make noises which make me worry).

For those who really want precision, you can always use a dial indicator. A jig to hold one for this purpose is commercially available. The purchase cost and the cost in setting time have never seemed worth it to me, but let's see what someone who uses one of these has to say.

Walt Fricke (who still will try many times to get it "just right")

I've been adjusting 911 valves to exactly .004" (.1mm) since 1995 (15-20 times) without any problems. I will continue to do so because I feel it is more consistent and repeatable.
Chris

[tummi]

Mr. jeffporsche,

your name sounds eerily familiar to someone who beat me out on ebay for a decklid recently. If so, no hard feelings; I got the next one up. As a new 911 owner (and my first post by the way), this was on the laundry list of things to do and I just crawled from under the car ('80sc) today with the job complete. Just a few comments to add apart from the tech article you've been referred to. When taking the covers off I had a handful of cover studs come off with the bolts - no big deal, just get the nuts off and screw them back in. Sometimes those missing studs actually helped with wrench clearance. On some studs I found it easier to use a regular wrench on others I found the offset wrench to work better so have both on hand. To get around the pre-muffler for the screw adjustment (or catalytic, I have the euro - your '74 i guess has neither), I used an offset screwdriver and a stub screwdriver on all others so again, have both of those on hand. Also, the blade on my feeler gauge broke off, fortunely i guess, when rechecking the clearance on #1 bottom. If it was on #6 top it probably would have been more pita to get out. I didn't jack up the car initially because i'm pretty small, but on #3 bottom i got frustrated and jacked it a little (with stands under the t-bar of course). Next time i jack. Otherwise things went by the book. Good luck on yours.

[Wayne 962]

"and if you are loose by a thousandth or two at most you might possibly have a bit more valve noise at idle. "

That statement is completely incorrect. You will indeed have more valve noise at idle, and at operating temp. You will also reduce the valve lift by a few thousandths as well, which will indeed affect performance. The valve will also open later, and close earlier.

Stick to the standard procedure - it's there for a reason...

-Wayne

[jeffporsche]

Dear Tummi,

The Red Sc Lid that I bid on was destroyed. You are a lucky man that you lost the bid. I recieved the lid and it had about 10 dents like someone hit it with a baseball bat. Of course after they hit it with a bat they ran it over warping the lid!!! My bodyman said that he could fabricate me a new lid for less than it would cost to fix the one that I bought from that joker. When I told him that it was damaged he said sorry I sold it as in good faith. He never stated that it was sold as is and I sent it back waiting for a refund. He lives in California so based on principle and the stubborn Irish man in me I will drive to his door and settle it in person if he does not refund me. E bay is great sometimes and sometimes it sucks..