First valve adjust... sUCCESS

[geof33]

So my first valve adjust (P-car anyway) went rather smoothly overall. No broken feeler tips and the car runs like a top.

Findings:

All valves "loose" except #4 exhaust which was a little tight. NO broken head studs!!! Overall, not bad.

Things to pass on:

1. BY THE LITTLE TOOL!!! Makes a HUGE difference.

2. Intake #1 HUGE P.I.T.A. to get to.

3. Buy a set of racheting box end wrenches, or at least a 13mm. Makes the tightening MUCH easier.

4. Patience. Patience. Patience.

5. Not too bad a job really, most time consuming thing is removing and replacing nuts (by hand without an air assist).

6. 2 beer job overall, not quite the nightmare it can be described as.

7. BIG savings and it is done RIGHT!!!

[MovOvr1]

I plan on checking mine later this season....thanks for the confident and encouraging post. Always procrastinate on that car......I guess I am afraid to screw something up.

Brian
79 930

[jester911]

Yes I just did my first one as well today after work. I finished the adjustment but have not put it back together yet. I plan on doing that tomorrow after work.

Hopefully the car will run smoothly.
Geoff, glad to here yours went well

[cjf]

I also just finished my first valve adjustment today. Finished putting her back together and started up tonite. GOD I missed the sound of the engine. Been parked for a month now. Can't wait for our 6 months of winter to be over. Only good thing about being parked is that I am getting to know alot more about the car and it is fun doing things that I never even considered before.

[RoninLB]

Originally posted by geof33

3. Buy a set of racheting box end wrenches, or at least a 13mm. Makes the tightening MUCH easier.

a friend says that the Craftsman ratcheting box is nicer to deal with than his Snap-On set.. I love that kind of Snap-On info.

[moosthuizen]

Ah.... the pleasure of a successful valve adjustment. This is what makes owning and working on a porsche so much more pleasurable.

Marius

[jmohn]

Did my own first 911 valve adjust last spring; although tedious, much less difficult than I expected. I haven't played with valve adjustment since the '60's (my hot rod days). What I found surprising was how little adjustment was necessary. I found only 4 exhaust valves actually needed adjusting (all slightly loose), and this after 20K since their last adjustment (yeah, I'd "let it go" longer than I should have). I have a theory that, driven "moderately", as my car is (it's my summer daily driver, no track time, very rarely any sustained high RPM use), the valve adjustment period could be substantially extended. I intend to check the adjsutment every 15-20K but I don't expect much adjustment will be required.

Jerry M
'78 SC

[tshih]

Valves rarely get tighter with miles driven. There is no harm in loose valve clearance, only noisier, less fuel efficiency and less than optimum
power. Over tightening is harmful in burning valves since they don't get to transfer the heat to their seats. Guides also gets ruined.

[billwagnon]

Actually, they should only get tighter as the valves "bed in" to the seats. I don't know why they would get looser.

[qcwang]

For all of you who have done this, how long did it take for your first time and then how long for subsequent valve adjustments, after learning curve?

Quincy

[billwagnon]

first time took me 8 hours

this weekend, I did it in 4, with a long break to think about things.

I think it is really difficult to screw up. My pulley shows two sets of TDC marks, so I pulled the #1 plug and used a screwdriver to identify the compression stroke. Watching the distributor come around to the mark on the distributure, and feeling the piston pushing out, you know you are on TDC.

After I did all the valves twice, I went back and checked #1 against my second set of TDC marks, and all was fine. I think there is a fairly wide path on the pulley arc for which the exhaust and intake valves are both closed.

[andrew johnson]

Great Post Guys

I have been preparing myself for this job, reading 101 Projects and the Readers Digest Book of the car (not to be scoffed at).

Has anyone got any warnings about valve adjustments for the neophyte?


Andrew

[CarreraS2]

One warning - always check the valve clearance before you loosen and start to adjust it.

if a valve seems really, really off, recheck that you have the cylinder at TDC.

These valves are very stable. If you get a reading that is way off (on the tight side) recheck TDC.

(If you get a reading way off on the loose side . . . then it's too loose no matter where the crank happens to be rotated)

[tshih]

Billwagnon,

How does the clearance get tighter when the locknut loosens up in time. The cam lobes actuate the valve rockers which actuates the top of the valve stem. The elephant foot screw backs up with time and the clearance gets bigger. For the clearance to get smaller you would have to be wearing out the seats (which I believe are hardened) everything else remaining the same.

[geof33]

This job took about 5 leisurely hours. I did not rush and had no agenda.

Other tips:

You can "wiggle" the rocker up and down to be certain you are on the correct one. It is also obvious which rocker is correct as the appear "up" compared to the rest. Line up the marks and watch the dist rotate, it's obvious which one you are on in the rotation.

As I said before, buy the tool. It really is indespensable. I don't think you can get them too tight unless you are a mechanical bonehead. If you can feel the feeler move in and out with slight resistance, you're good. If you can't get it in or remove it, it's too tight. It is more likely to err on the loose side. If your nitpicky you can dial the valves to perfection.

Driving observations, definately quieter... seems spunkier. Don't know about mileage yet...

I'm happy it went well...

One other thing, definately surface your exhaust covers. NO LEAKS!!!!

[jtcmuga]

I did my first valve adjustment two months ago. Eight hours seems right, I had guidance from a good friend that has done it before, too. Patience is key. DIY gives you an unexplainable feeling of content...

Jojo

[billwagnon]

How does the clearance get tighter when the locknut loosens up in time.

The thought of the locknuts or screws loosening frightens me! Shouldn't they be tight all the time? How many miles until they just back all the way off?

I think wear of the valves and seats is more likely than loose locknuts. The valve is contacting the seat once every rotation (at 2000 rpms that's 2000 times per minute; each hour results in 120,000 contacts); the exhaust valves are also relieving very hot exhaust and have more thermal stress.

Last time most of my valves were fine; a couple were tight. I don't think any were too loose but then I only had 3500 miles between adjusts.

[jester911]

Well I finally got time this afternoon to put my car back together after my valve adjustment.

It may just be wishful thinking but the thing actually feels more responsive. It was my first one as well so a real learning experience but in a good way.

Thanks goes to this board and all of you guys in it that give guys like me the info and confidence to tackle these jobs.

Last adjustment cost me about 400 bucks.

This one was about 50 or so and it really was enjoyable gaining the knowledge of the actual inner workings of the engine.

Okay, enough talking. I think I will go drive it some more

[tshih]

Billwagnon,

Unless the locknuts were left really loose they don't loosen up that easily so rest in peace. You should really recognize the sound of loose valve rockers compared to well adjusted ones. I think most experience owners who drive and listen to their cars a lot know when it is time to get the valves adjusted. Going 40K miles between adjustment is not going to be detrimental to the engine. Going 1000 miles with tight clearance can burn the valves.

[RoninLB]

Originally posted by tshih

. Going 1000 miles with tight clearance can burn the valves.

fwiw, a machinist pelicanhead measured a few of the routine feeler blades we use and he measured a slight over-thickness.

and marcesq uses a .005 feeler to confirm if he's loose or not.