<VV> 102 head replacement

[Marc Sheridan]

----- Original Message ----- 
From: "lloyd biggerstaff (by way of "Harry Jensen, CORSA Executive
Secretary" <corsa@corvair.org>)" <lloydscorvan@yahoo.com>
> If I do not adjust the lash correctly after replacing the heads, is there
a
> chance it will not start?

Yes, if you over tighten them, it will hold the valves open  and it will not
start. Matt's rule is "three threads a showin' and it's a goin'". What that
means is, if you have more than three threads showing about the adjusting
nut, you may have over tightened them, which is easy to do, until you get
the "feel" for where zero lash is. The "break point" at zero lash is very
subtle, but once you confidently find it, you'll know everytime.

Below is Ken Hand's procedure, which has been repeated here many times and
really helped me. He does each cylinder individually, but you can do it the
way the manual says (for TDC) and get the same result. Good luck.

Marc Sheridan


>From Ken Hand:
> I will try to answer what you are saying/asking with my opinion.
> First a few parameters, when I replace lifters I use SBC lifters with the
> disc valve, when I adjust valves, even corvair original, I use 3/4 turn,
and
> I adjust one cyl. at a time at TDC.
>     My turn to ask a question; Why do you adjust valves hot and running?
> I think the answer may lie in the OLD DAYS when you had to adjust
mechanical
> valves running and with a feeler gauge, I still have some of the tools.
>     Also to let everyone know I vary quite a bit from the shop manual when
it
> come to certain things -- see above 3/4 turn, and SBC lifters -- so to me
the
> shop manual is a guide not the Bible.
>     Now for some specific reasons, hydraulic lifters, wonderful things
that
> let you take all the clearance out for quiet movement and not have to be
> perfect or exactly on the money for best overall performance. You can
adjust
> SBC lifters on the corvair from as little as 1/16th of a turn or all the
way
> to 1 1/2 turns and the lifter will still perform the same way it was
designed.
>     You ask "why adjust cold"? Most of it has been said before but I will
> reiterate some and add some new, maybe.
>     The list, ease of working conditions, cleanliness,
> open the engine up once, or on a rebuild never,
> you don't have to destroy a part to make a shield
> you won't burn yourself!  (GRIN)
> The cold adjustment can be more precise and the BIGGIE, it takes less
time.
>     I have found over the years that people are to impatient for the
running
> method and won't or don't wait for things to settle properly. Here is an
> example someone puts lifters in an engine, they preadjust, run the engine
for
> a few minutes, open up the rocker cover, make a mess with dripping hot
oil,
> start the engine, now you have hot spraying oil all over, back the
adjusting
> nut off until it clatters (or is that the one next to it?), then you
tighten
> slowly until the clatter stops (but the others are making noise, are you
hard
> of hearing?), once the clatter stops on that valve you adjust slowly, no
more
> than a 1/4 turn until the engine smoothes out again, the clatter is still
> there, you adjust another 1/4 turn, this continues until you get nervous
> about how far down you've taken the nut, ( or you don't know any
different),
> then pretty soon, finally QUIET!  BUT GUESS WHAT? You've bottomed out the
> lifter to make it quiet and now the lifter cannot function the way it was
> designed. Now you think you have the cat by the tail because the engine is
> running OK and pretty quiet as far as lifter noise goes. You then put
rocker
> covers on and clean up the mess that was made by all the oil splashing
> everywhere. Now you drive your car and all is well.
>     Next time you go to drive the car there is this funny little thing
> happening in the engine that wasn't there before and you check and check
and
> finally do a compression test and find you have low compression on one or
two
> cyls. And you ask why and find out that you need to adjust valves all over
> again!
>     The way I adjust valves, new or used is this way;
> If the car is driven to you LET ENGINE COOL!
> Jack up one side of the car kinda high and use jack stands,
> Then pull off the corresponding valve cover
> Watching the valve motion of the cyl you wish to adjust bring that cyl to
TDC
> or very close,
> loosen the rocker arm until there is movement up and down.
> With oily fingers on one hand pinch the pushrod and twist back and forth
as
> you tighten the rocker down, do not hold to tight on the pushrod, once you
> get to the spot that, with light pressure you can't twist the pushrod
remove
> your adjusting tool and move the rocker slightly side ways to see if it
was
> off center of the valve and now the pushrod may move easily again so go
and
> tighten the nut some more while twisting the pushrod until it stops again,
> double check the rocker for being straight and if so then you are at ZERO
> LASH.
>     From here you adjust the nut to 3/4 of a turn, I find it easy to do 3,
> 1/4 turns.
> Repeat this process on the adjacent valve.
> Now go to the next cyl find TDC and repeat the whole process on the
remaining
> cyls.
> INSTALL THE ROCKER COVER PERMANENTLY!
> Let the car down on that side and Jack up the other side and finish the
job
> as stated earlier.
> Now the kicker that everybody hates, start the engine and you will
probably
> have some lifter noise! GO HAVE A COFFEE, SODA, OR TEA but walk away, do
not
> jump right back in and want to adjust some more, when you come  back the
> magic is done, and if done properly the engine will be as quiet as new.
>  The reason for adjusting one side at a time is when you jack up the one
side
> all the oil goes to the other side and when the cover comes off there are
> only a few drops to take care of instead of 1/2 quart.
>     I don't know if this answers all of your questions, but hope fully
this
> has taken some of the mysticism out of the cold adjustment. I will add
that
> if you try this and it works for you, you will never again adjust valves
> running and hot!
>     I must also add that we all know there are bad parts out there even
out
> of the box new.
>
> Ken Hand
> HANDY CAR CARE
> 97 Peach
> Pontiac, Mi., 48342
> 248-613-8586