E30 M3 Valve Adjustment.

[Josh <eurosprt@xxxxxxxxxxxx>]

Jose,

>I'd like to adjust the valves on my M3, but I have no idea 
>since it's the first time in my life that I'm going to try that. 

I wouldn't recommend adjustment of an E30 M3 as your first valve adjustment
ever.


>The only information I have is a report written in the Digest 
>FAQ, section 11.2 which is a little hard for a novice, and a 
>report for installing a cam sprocket on E30 M3 by Bob Stommel 
>which hasn't any valve adjustment content, but helps a lot 
>with the torque values and disassemble procedures. 


The only torque value that should be of concern for a valve adjustment of
the S14 is the valve cover nuts (approx. 7ft/lbs).


>At the moment, I have removed the valve cover and I'm trying to 
>look for my feeler gauge that should be somewhere in my garage:-| 
>My first doubt is: what do you adjust there?


You adjust the valves by removing the pucks/shims (using a very special BMW
tool $300.00 + dollars) that are on the top of the valve tappet buckets and
swapping them out with shims that will appropriately change the clearance
between cam lobe and tappet. The pucks in the S14 are the same as the pucks
that are in the Volvo (much cheaper @ $4.00ea vs BMW $8.00ea).  You will
also need compressed air so you can pop the shims out of the top of the
tappet.


>I have seen that the 
>cam hits a kind of solid cylinder, which has another cylinder inside. 
>Is that second cylinder what you call "shim".

This is the "shim" and the outer ring of the cylinder is part of the valve
tappet.


>The report I have talks 

>about replacing shims (if necessary), but it doesn't mention any clearance 
>adjustment, so I wonder whether the valve adjustment on the M3 is so simple 
>as remove and replace those shims.... 

Not nearly as simple as you think.  First you rotate the engine to achieve
proper cam lobe position and measure all of the valve clearances between
the base lobe of the cam and the tappets.  As you are taking the
measurements of the valve clearances you will need to remove the shims and
measure them with a micrometer (a hell of a lot easier if you have a
digital micrometer).  If you have a complete valve shim kit you will be
able to summarily calculate the differences (get ready for an oily mess of
your calculator, pad, and pencil) and swap out the shim to achieve proper
valve clearance.  You will then need to check for proper adjustment (bummer
if it isn't right cause you get to try again).  Of course if you don't have
a proper shim assortment (which I would assume is your situation) you will
probably want to put the shim back in so you can continue taking
measurements of the rest of the valve clearances.  You use the special BMW
tool (# 11 3 170) to depress the valve buckets while you use compressed air
to blow the shim out of the top of the tappet (get ready for oily hair and
contac lenses/eyeballs/glasses/garage/rolling rock/hooter girl).  I would
recommend doing the adjustment naked as it will awaken the primevil beast
within.


>I accidentally touched one of those cylinders and it moved very 
>easily some degrees on the right. I hope I don't have made a mistake there. 


The tappets are supposed to rotate easily and do constantly while the
engine is running.


>What is the purpose of the notches in those cylinders?

These are the notches that you blow the compressed air into to pop the shim
out of the top of the buckets.

>I'd appreciate if someone out there could give me a detailed procedure 
>for novices about the valve adjustment on the E30 M3.


>Thanks in advance 
>Cheers 
>Jose Santana <mpower@domain.elided> 
'>83 316 
'>88 ///M3

There is a first time for everyone, but I would recommend a few M20 or M30
adjustments first.  The valve adjustment on the S14/S38 motor is so fun
that I was the first mechanic at our local dealership to ever do one.  Most
mechanics avoid them and make excuses like "the M motors don't need
adjustment" etc.  M motors do go out of adjustment, but at a slower pace
than the other BMW engines.  Either way the should be checked at least
every 30K miles or more if you are racing.


Josh
Eurosport
801 463 4919

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