Valve Adjustments

-- Group Message from Carl Beck <cbeck@becksystems.com> --

>Dan Baldwin wrote:

>Knew Kyle would beat me to a reply!

>>Valve clearances should be .010I, .012E

>Huh?! Actually, when I set mine the other day, I was doing it to

>what I was accustomed to, .008I, .010E. Then I thought I'd check

>the Haynes manual halfway through, and IT specifies .010/.012!

>Damn, I thought. Then I checked Schneider's web site (Schneider

>cam in my car) and fortunately it listed lash specs, .008/.010.

>But I swear I remember .008/.010 as being correct for stock, too,

>cuz when I had the Bmer (85 535i), I knew its specs were for more

>lash than the Z, and it called for .010/.012.

>I think the Haynes manual might be wrong. Anybody know for sure?

>Hate to think of all those Zs out there not getting all the lift

>and duration they deserve!

Hi Guys:

Just so we don't get carried away with worry over a thousandth of an inch

one way or the other...;-). The Factory Manuals specify the valve lash for

a car when new...

They specify: Intake Exhaust

HOT Setting 0.25mm (0.0098 in) 0.30mm (0.0118 in)

With a reground cam - the lash spec.'s could very will change. Likewise,

with an engine with 100K+ miles on it, the original Factory Spec.'s may not

be the best for your car.

Most of the time the valves will tighten themselves down over time... also

with worn parts the original factory spec.'s may result in a lot of extra

valve noise. Even though you are keeping the valve lash the same - other

parts of the valve train wear and increase their tollerances (valve train

slop)... sometimes your better off running a thousandth or two tighter

valve lash on a high milage engine...

It's a matter of some trial and error - but you want to be close to the

original spec.'s - and you want the least valve train noise... The rational

being that excessive valve lash results in excessive valve train noise and

parts that are hammering themselves to death... to little clearence and you

get excessive wear.. On a high milage engine if the factory spec.'s result

in a lot of valve "tappit tick" - I'd give them a try at 0.008 and 0.010

and see what they sound like...

If you have never adjusted the valves yourself - I agree with who ever said

get Scott's Video. I'll add this:

1. Get yourself some good high quality, thin profile wrenches.. that fit

the nuts exactally - the longer the handles the better for the beginner.

Longer wrenchs allow you to keep your hands farther away from the head to

begin with - and they allow you to put a little more torque on the nuts

(better leverage for weaker hands like mine).

2. Get yourself a small brass hammer - to tap the wrenches and break the

lock nuts lose as well as to tap them tight again. (a brass hammer won't

bounce back when it strikes the wrench).

3. The first few times - wear leather work gloves. The edge of that head

is like a razor - a couple of slips while twisting the wrench and you will

lose a lot of blood. (Item #2 above helps greatly to prevent slipping when

your putting a lot of pressure on the wrench - a little pressure and a

light tap with a heavy brass hammer is much safer ;-)..

OK -

1. Adjust the valves on the engine cold - FIRST. This will let you loosen

the nuts etc and get used to adjusting the lash and tightening things back

down - without burning your hands.

2. Warn the engine up - and then recheck the valve lash - adjust if necessary.

Don't be afraid to try it - and do it several times - even if you don't

have to - it's just one of thoes things you have to put some time into...

Good tools and the right tools make the whole thing much easier to master...

Good luck,

Carl

Carl Beck

Clearwater,FL

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