ADJUSTING VW VALVES -- AGAIN

I get a LOT of mail about adjusting the lash on Volkswagen valves, and
much of that mail comes from folks who are FLYING behind a converted
VW engine, making it a valid topic for this Newsgroup.

The basic message is that for an in-service engine you DO NOT use the
adjustment procedure shown in the Factory Service Manual... which has
been included in the ABRIDGED version of the "official" VW manual, as
offered by Volkswagen of America (ie, VOA) through their dealers and
other retail outlets.

The method shown in those manuals is for an engine that is being RE-
ASSEMBLED, or assembled for the first time. That is, for an engine
that is NOT in-service. It is for a NEW engine or a HEAD that has
been overhauled.

(running out of time)

The method used for in-service engines uses the thread of the adjuster
screw as a micrometer and is accurate to five ten-thousandths of an
inch, which is more than accurate enough.

Here is how you do it:

(Since there are any number of after-market rocker arms out there, I
have no way of knowing the pitch of your adjusting screws. And
neither do you. So that is the first thing we will establish.)

Remove an adjuster from its rocker-arm. If you do not have a spare
rocker-arm handy you will have to remove the entire rocker arm shaft
to do this.

Put a piece of white paper on a compliant surface, such as the
'official' service manual. At one edge of the white paper, PRESS the
adjusting screw down on the paper hard enough to make an impression.
My thumbs are hard & callused and work just fine for this sort of
thing. But if your thumbs are not my thumbs you may need to use a
piece of wood to press HARD ENOUGH on the adjuster. The goal is to
make an impression of the threads on the white paper. Use whatever
works to accomplish the goal.

Using a ruler, such as a machinist's 6" pocket scale or any other
ruler known to be accurate, measure ONE INCH of the impression. Use a
sharpened pencil to mark-off one inch of threads.

Count the threads.

You should have about twenty-two and one-half threads to the inch.
Some after-market adjusters have more, a few have less. We want to
know how many their are on YOUR adjusters.

Using WHATEVER count you have for threads-per-inch, divide that amount
into one. That is, 1.0000 divided by 22.5 equals .04444" or about
four-hundredths of an inch.

Still with me? I've used 22.5 threads per inch (TPI) because that's
what I got from MY adjusting screws. You may have something different
but it will be ABOUT 22 TPI. If it is NOT close to 22 TPI, send me a
PRIVATE message telling me what you've got -- I don't want to clutter
up the Newsgroup with something that should be on a VW-specific
channel.

Four hundredths of an inch... or rather .0444" is how far the adjuster
will travel for ONE FULL TURN.

The lash or COLD clearance for Volkswagen valves is ABOUT six
thousandths of an inches... that is .006" That amount of lash is a
COMPROMISE that will work for both intake and exhaust but it is for
STOCK valves. If your valves are NOT stock you may need more or less
clearance. If that is the case, find out what your valve clearance
should be and send me a private msg, and I will tell you how to adjust
your valves using this procedure.

If one full turn will advance the adjusting screw four hundredths of
an inch, since there are 360 degrees in one full turn, we want to find
out how many degrees we must rotate the adjuster to give us six
thousandths of an inch.

The answer is ABOUT forty-five degrees, which is ABOUT one-eighth of a
turn. Now let's go and adjust your valves.

With the vehicle blocked at the front wheels, use a jack under the
REAR transmission mount to raise the vehicle high enough to give you
some work space. Put a JACK STAND under EACH END of the torsion bar
housing. Remove the jack and put down card-board or canvas to lay
upon. Now grasp the rear bumper and give the vehicle a good SHAKE...
try to make it fall. If it does not fall you may assume it is safe to
work under the vehicle.

Using a wrench, rotate the engine to Top Dead Center (TDC) for EITHER
cylinder #1 OR cylinder #3.

Crawl under the vehicle and remove BOTH valve covers.

There are any number of ways to accomplish the above. Some involve
removing the rear wheels, some can be accomplished without using a
jack, and so forth. The goal here is to provide the working space
needed to adjust the valves. WHATEVER method works is valid, so long
as it does not make it unsafe to work under the vehicle.
This is a COLD adjustment but in this case 'cold' means any
temperature at which you can put your hand on the head without burning
yourself. In fact, it means any temperature from stone cold to about
120 degrees on the Fahrenheit scale.

When you are laying on your back under your Volkswagen it is difficult
to manipulate a screw driver and a wrench AND a feeler gauge,
especially when the adjustment you are making is nothing more than a
COMPROMISE, in that the valves will commence wearing themselves OUT OF
ADJUSTMENT as soon as the engine is started.

Still with me? Your valve adjustment is a COMPROMISE. It is never
perfect for more than a few SECONDS immediately following an
adjustment. And when that is the case, it is valid to use an
ADJUSTING PROCEDURE that gives the APPROXIMATE lash. So here is how
to do it:

You're laying under the vehicle. You've just removed the last valve
cover. Reach up and try to rock the rockers back and forth. There
will be some play or movement on some of the valves whilst the other
valves will not move at all.

(NOTE: -----------------------------------------------------------

The adjusting screw is made of SOFTER STEEL than your valves. While
laying under the vehicle, examine your valve stems and your
adjusters. If the adjuster is mushroomed it should be replaced. On
average, the STOCK adjuster needs to be replaced after just FOUR
adjustments. This is because the softer steel wears quite rapidly AND
the contacting face of the adjuster screw is CAMBERED. That is, the
face of the screw is finished to a gentle CURVE. When the adjuster
wears, the curved face of the adjuster screw becomes FLAT. When flat,
it will HAMMER the face of the valve stem instead of SLIDING across
the face. Given enough time, the flattened adjuster will mushroom the
face of the valve stem even though the valve is made of harder steel.
Adjusters used to be quite inexpensive (twelve or thirteen cents
each... in 1956). They were replaced so often that who ever was in
charge of the Parts Department kept a ready supply of adjuster screws
right beside the window where the mechanics would ask for parts. (The
Work Order was kept in a rack immediately adjacent to the Parts
window.) This was true for any part which was frequently replaced.
In the late 1960's the grommet that went around the fuel pipe where it
penetrated the breast tin joined the 'ready issue' ranks...for six or
seven cents each. (The test was for the mechanic to compress the
rubber with a CLEAN thumb-nail (No grease, please). If the grommet
could not be compressed with the thumb-nail, it was replaced.)

If EITHER the adjuster or valve stem is mushroomed, it is good
evidence that the vehicle has NOT been receiving proper maintenance
and justifies a chat between the Service Writer and the customer.

If the valve stem is mushroomed it may be time to replace the head,
since a grooved or mushroomed valve stem willl not rotate properly.
Installing a new adjuster will not cause the valve stem to HEAL
itself. If the damage to the valve stem is great enough, the head
should be replaced since a new adjust will be worn flat in as little
as 100 miles.

However, if the rockers are fitted with swivel-foot adjusters, as
introduced by Ford of Germany in 1956, and later used on Porsche,
Subaru and other engines, so long as the head receives adequate
LUBRICATION the valve 'adjustment' may be extended to 10,000 miles (!)
and limited to a visual inspection for any vehicle being serviced at
less than that interval. (There should be an entry in the Owner's
Service Notebook that the engine has been fitted with flat-faced
adjusters. These were quite expensive and had a tendency to wander
away from any vehicle so fitted.)
(END OF NOTE: ---------------------------------------------------

Using your box-end wrench LOOSEN the adjusters on all of the loose
rockers. Use the box-end or your finger to run the nut out at least
two turns. Now back-out the adjusters with your screwdriver... make
sure it is loose. Then run it back IN until it TOUCHES the valve
stem. Do not apply so much pressure that you compress the valve
spring but DO run the adjuster in & out several times until you are
sure you are feeling a good 'touch.'

Turn the adjusters of any LOOSE valves down until the adjuster is
TOUCHING the valve stem.

With your box-end on the shaft of your SCREWDRIVER, insert the blade
(*) into the adjuster an back the adjuster OUT forty-five degrees --
or one-eighth of a turn. HOLD the adjuster in that position while you
TIGHTEN the lock-nut. Repeat this procedure for any other valves on
that head which were LOOSE.

Slide over to the other head and REPEAT THIS PROCEDURE.

When both heads have been done, ROTATE the engine ONE FULL REVOLUTION
to TDC.

REPEAT THE ABOVE PROCEDURE.

Have someone inspect your work.

Replace the valve covers

-----------------------------------------------------------------------------------------------------------

The Flat Rate Manual for an air-cooled Volkswagen allowed 0.2 m/hr (ie
12 minutes!) for a valve adjustment but most experienced VW mechanics
needed only five minutes or so. Most of the time spent by the man in
the pit was for INSPECTIONS. When you brought your bug or bus into an
authorized VW dealer for SERVICE it received something on the order of
125 INSPECTIONS... and about fifteen items for WORK, such as changing
the oil. (If you have an original Owner's Handbook simply read the
list at the back of the book.)

In FLYING VOLKSWAGENS the engine is doing far more work than it had to
do when installed in a vehicle. The RPM may be similar but the
airplane is typically run at Wide Open Throttle (ie, WOT) or close to
it. That means the inspections specific to LUBRICATION FAILURE must
be emphasized since the engine was simply never designed to run at WOT
for more than a few minutes at a time. In the case of the valve
train, running at WOT usually results in accelerated wear of the
rocker arms, the rocker arm shaft, the warshers, both flat & warpy,
and the hair-pins. These components require MORE oil than the STOCK
system can provide. Increasing the amount of oil reaching the heads
should be one of the first steps in modifying a VW engine for flight.
The necessary modification can be found in my blog.

-R.S.Hoover

Bob you are a wealth of information that is appreciated! ;-)

thanks!
--
later,
(One out of many daves)


"Bob Hoover" > wrote in message
...
>I get a LOT of mail about adjusting the lash on Volkswagen valves, and
> much of that mail comes from folks who are FLYING behind a converted
> VW engine, making it a valid topic for this Newsgroup.
>
> The basic message is that for an in-service engine you DO NOT use the
> adjustment procedure shown in the Factory Service Manual... which has
> been included in the ABRIDGED version of the "official" VW manual, as
> offered by Volkswagen of America (ie, VOA) through their dealers and
> other retail outlets.
>
> The method shown in those manuals is for an engine that is being RE-
> ASSEMBLED, or assembled for the first time. That is, for an engine
> that is NOT in-service. It is for a NEW engine or a HEAD that has
> been overhauled.
>
> (running out of time)
>
> The method used for in-service engines uses the thread of the adjuster
> screw as a micrometer and is accurate to five ten-thousandths of an
> inch, which is more than accurate enough.
>
> Here is how you do it:
>
> (Since there are any number of after-market rocker arms out there, I
> have no way of knowing the pitch of your adjusting screws. And
> neither do you. So that is the first thing we will establish.)
>
> Remove an adjuster from its rocker-arm. If you do not have a spare
> rocker-arm handy you will have to remove the entire rocker arm shaft
> to do this.
>
> Put a piece of white paper on a compliant surface, such as the
> 'official' service manual. At one edge of the white paper, PRESS the
> adjusting screw down on the paper hard enough to make an impression.
> My thumbs are hard & callused and work just fine for this sort of
> thing. But if your thumbs are not my thumbs you may need to use a
> piece of wood to press HARD ENOUGH on the adjuster. The goal is to
> make an impression of the threads on the white paper. Use whatever
> works to accomplish the goal.
>
> Using a ruler, such as a machinist's 6" pocket scale or any other
> ruler known to be accurate, measure ONE INCH of the impression. Use a
> sharpened pencil to mark-off one inch of threads.
>
> Count the threads.
>
> You should have about twenty-two and one-half threads to the inch.
> Some after-market adjusters have more, a few have less. We want to
> know how many their are on YOUR adjusters.
>
> Using WHATEVER count you have for threads-per-inch, divide that amount
> into one. That is, 1.0000 divided by 22.5 equals .04444" or about
> four-hundredths of an inch.
>
> Still with me? I've used 22.5 threads per inch (TPI) because that's
> what I got from MY adjusting screws. You may have something different
> but it will be ABOUT 22 TPI. If it is NOT close to 22 TPI, send me a
> PRIVATE message telling me what you've got -- I don't want to clutter
> up the Newsgroup with something that should be on a VW-specific
> channel.
>
> Four hundredths of an inch... or rather .0444" is how far the adjuster
> will travel for ONE FULL TURN.
>
> The lash or COLD clearance for Volkswagen valves is ABOUT six
> thousandths of an inches... that is .006" That amount of lash is a
> COMPROMISE that will work for both intake and exhaust but it is for
> STOCK valves. If your valves are NOT stock you may need more or less
> clearance. If that is the case, find out what your valve clearance
> should be and send me a private msg, and I will tell you how to adjust
> your valves using this procedure.
>
> If one full turn will advance the adjusting screw four hundredths of
> an inch, since there are 360 degrees in one full turn, we want to find
> out how many degrees we must rotate the adjuster to give us six
> thousandths of an inch.
>
> The answer is ABOUT forty-five degrees, which is ABOUT one-eighth of a
> turn. Now let's go and adjust your valves.
>
> With the vehicle blocked at the front wheels, use a jack under the
> REAR transmission mount to raise the vehicle high enough to give you
> some work space. Put a JACK STAND under EACH END of the torsion bar
> housing. Remove the jack and put down card-board or canvas to lay
> upon. Now grasp the rear bumper and give the vehicle a good SHAKE...
> try to make it fall. If it does not fall you may assume it is safe to
> work under the vehicle.
>
> Using a wrench, rotate the engine to Top Dead Center (TDC) for EITHER
> cylinder #1 OR cylinder #3.
>
> Crawl under the vehicle and remove BOTH valve covers.
>
> There are any number of ways to accomplish the above. Some involve
> removing the rear wheels, some can be accomplished without using a
> jack, and so forth. The goal here is to provide the working space
> needed to adjust the valves. WHATEVER method works is valid, so long
> as it does not make it unsafe to work under the vehicle.
> This is a COLD adjustment but in this case 'cold' means any
> temperature at which you can put your hand on the head without burning
> yourself. In fact, it means any temperature from stone cold to about
> 120 degrees on the Fahrenheit scale.
>
> When you are laying on your back under your Volkswagen it is difficult
> to manipulate a screw driver and a wrench AND a feeler gauge,
> especially when the adjustment you are making is nothing more than a
> COMPROMISE, in that the valves will commence wearing themselves OUT OF
> ADJUSTMENT as soon as the engine is started.
>
> Still with me? Your valve adjustment is a COMPROMISE. It is never
> perfect for more than a few SECONDS immediately following an
> adjustment. And when that is the case, it is valid to use an
> ADJUSTING PROCEDURE that gives the APPROXIMATE lash. So here is how
> to do it:
>
> You're laying under the vehicle. You've just removed the last valve
> cover. Reach up and try to rock the rockers back and forth. There
> will be some play or movement on some of the valves whilst the other
> valves will not move at all.
>
> (NOTE: -----------------------------------------------------------
>
> The adjusting screw is made of SOFTER STEEL than your valves. While
> laying under the vehicle, examine your valve stems and your
> adjusters. If the adjuster is mushroomed it should be replaced. On
> average, the STOCK adjuster needs to be replaced after just FOUR
> adjustments. This is because the softer steel wears quite rapidly AND
> the contacting face of the adjuster screw is CAMBERED. That is, the
> face of the screw is finished to a gentle CURVE. When the adjuster
> wears, the curved face of the adjuster screw becomes FLAT. When flat,
> it will HAMMER the face of the valve stem instead of SLIDING across
> the face. Given enough time, the flattened adjuster will mushroom the
> face of the valve stem even though the valve is made of harder steel.
> Adjusters used to be quite inexpensive (twelve or thirteen cents
> each... in 1956). They were replaced so often that who ever was in
> charge of the Parts Department kept a ready supply of adjuster screws
> right beside the window where the mechanics would ask for parts. (The
> Work Order was kept in a rack immediately adjacent to the Parts
> window.) This was true for any part which was frequently replaced.
> In the late 1960's the grommet that went around the fuel pipe where it
> penetrated the breast tin joined the 'ready issue' ranks...for six or
> seven cents each. (The test was for the mechanic to compress the
> rubber with a CLEAN thumb-nail (No grease, please). If the grommet
> could not be compressed with the thumb-nail, it was replaced.)
>
> If EITHER the adjuster or valve stem is mushroomed, it is good
> evidence that the vehicle has NOT been receiving proper maintenance
> and justifies a chat between the Service Writer and the customer.
>
> If the valve stem is mushroomed it may be time to replace the head,
> since a grooved or mushroomed valve stem willl not rotate properly.
> Installing a new adjuster will not cause the valve stem to HEAL
> itself. If the damage to the valve stem is great enough, the head
> should be replaced since a new adjust will be worn flat in as little
> as 100 miles.
>
> However, if the rockers are fitted with swivel-foot adjusters, as
> introduced by Ford of Germany in 1956, and later used on Porsche,
> Subaru and other engines, so long as the head receives adequate
> LUBRICATION the valve 'adjustment' may be extended to 10,000 miles (!)
> and limited to a visual inspection for any vehicle being serviced at
> less than that interval. (There should be an entry in the Owner's
> Service Notebook that the engine has been fitted with flat-faced
> adjusters. These were quite expensive and had a tendency to wander
> away from any vehicle so fitted.)
> (END OF NOTE: ---------------------------------------------------
>
> Using your box-end wrench LOOSEN the adjusters on all of the loose
> rockers. Use the box-end or your finger to run the nut out at least
> two turns. Now back-out the adjusters with your screwdriver... make
> sure it is loose. Then run it back IN until it TOUCHES the valve
> stem. Do not apply so much pressure that you compress the valve
> spring but DO run the adjuster in & out several times until you are
> sure you are feeling a good 'touch.'
>
> Turn the adjusters of any LOOSE valves down until the adjuster is
> TOUCHING the valve stem.
>
> With your box-end on the shaft of your SCREWDRIVER, insert the blade
> (*) into the adjuster an back the adjuster OUT forty-five degrees --
> or one-eighth of a turn. HOLD the adjuster in that position while you
> TIGHTEN the lock-nut. Repeat this procedure for any other valves on
> that head which were LOOSE.
>
> Slide over to the other head and REPEAT THIS PROCEDURE.
>
> When both heads have been done, ROTATE the engine ONE FULL REVOLUTION
> to TDC.
>
> REPEAT THE ABOVE PROCEDURE.
>
> Have someone inspect your work.
>
> Replace the valve covers
>
> -----------------------------------------------------------------------------------------------------------
>
> The Flat Rate Manual for an air-cooled Volkswagen allowed 0.2 m/hr (ie
> 12 minutes!) for a valve adjustment but most experienced VW mechanics
> needed only five minutes or so. Most of the time spent by the man in
> the pit was for INSPECTIONS. When you brought your bug or bus into an
> authorized VW dealer for SERVICE it received something on the order of
> 125 INSPECTIONS... and about fifteen items for WORK, such as changing
> the oil. (If you have an original Owner's Handbook simply read the
> list at the back of the book.)
>
> In FLYING VOLKSWAGENS the engine is doing far more work than it had to
> do when installed in a vehicle. The RPM may be similar but the
> airplane is typically run at Wide Open Throttle (ie, WOT) or close to
> it. That means the inspections specific to LUBRICATION FAILURE must
> be emphasized since the engine was simply never designed to run at WOT
> for more than a few minutes at a time. In the case of the valve
> train, running at WOT usually results in accelerated wear of the
> rocker arms, the rocker arm shaft, the warshers, both flat & warpy,
> and the hair-pins. These components require MORE oil than the STOCK
> system can provide. Increasing the amount of oil reaching the heads
> should be one of the first steps in modifying a VW engine for flight.
> The necessary modification can be found in my blog.
>
> -R.S.Hoover

What about roller-rockers.
That's what was put in mine.

On Dec 18, 5:20*pm, John J > wrote:
> What about roller-rockers.
-------------------------------------------------------------
Dear John,

I've no idea.

There are lots of non-stock arrangements that I've never seen nor
worked with. I've got to assume that whoever is using such stuff is
fully aware of it's service/maintenance specs.

-Bob

On Dec 18, 1:46*pm, "dave AKA vwdoc1" >
wrote:
> Bob you are a wealth of information that is appreciated! *;-)
>--------------------------------------------------------------------------------------------

Dear Dave,

Mis-information too. :-)

A fellow over on the VW vehicle list tapped me on my pointed head and
reminded me that I'd forgotten to include one of the most critical of
the inspections you're supposed to do, which is to check for a rock
that is tight at BOTH of the TDC settings. That means the valve has
'grown'... or the adjustment has 'grown.' Or some other failure has
occurred (such as a loose valve seat). Because if the rocker is tight
in BOTH positions it means something's wrong... and you'll need to
pull the head to figure it out.

-Bob

In article
>,
Bob Hoover > wrote:

> On Dec 18, 1:46*pm, "dave AKA vwdoc1" >
> wrote:
> > Bob you are a wealth of information that is appreciated! *;-)
> >-----------------------------------------------------------------------------
> >---------------
>
> Dear Dave,
>
> Mis-information too. :-)
>
> A fellow over on the VW vehicle list tapped me on my pointed head and
> reminded me that I'd forgotten to include one of the most critical of
> the inspections you're supposed to do, which is to check for a rock
> that is tight at BOTH of the TDC settings. That means the valve has
> 'grown'... or the adjustment has 'grown.' Or some other failure has
> occurred (such as a loose valve seat). Because if the rocker is tight
> in BOTH positions it means something's wrong... and you'll need to
> pull the head to figure it out.
>
> -Bob

One of the advantages of checking your own valves besides the engine
temp. is the note you might make if a valve is tight two times in a rou,
a.k.a. stretching. it means the valve is about to break off and ... well
it might make a little noise.
--
When the Power of Love,replaces the Love of Power.
that's Evolution.