Date: Fri, 15 Apr 2005 22:01:17 -0500
Reply-To: Bruce Nadig <motorbruce@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Bruce Nadig <motorbruce@HOTMAIL.COM>
Subject: Re: Valve clearance not at tdc?
Content-Type: text/plain; format=flowed
Howdy From Texas,
I'll be the first to admit that I could be completely wrong, but the answer
to this one seems very simple.
Assume the valves on cylinder are set properly. Next you will adjust the
valves on cylinder #2. When #2 is at TDC, the valves on cylinder #1 have
started doing their thing. During the 4-stroke cycle you have many times
that any given cylinder will have one valve closed (thus having clearance)
while the other is open.
Let me give a somewhat simplified example. As cylinder #1 begins its intake
stroke the exhaust valve will remain closed while the intake valve will be
open. As the piston rises (the compression stroke), the exhaust remains
closed and the intake valve will begin to close. During the the combustion
stroke, both valves are closed once again. As the exhaust stroke begins the
exhaust valve will open while the intake valve remains closed.
As you can see, there are numerous times that one valve is closed while the
other is open. When a valve is fully closed there should be clearance
between the valve and the rocker arm or lifter.
It seems to me that this is when you are finding one valve with no clearance
and the other valve presenting some clearance. Make sense? I'd put money on
this being what you are experiencing.
Cheers,
Bruce
motorbruce
motorbruce@hotmail.com
>From: Nate Saylor <nates@IMPULSE.NET>
>Reply-To: Nate Saylor <nates@IMPULSE.NET>
>To: vanagon@GERRY.VANAGON.COM
>Subject: Valve clearance not at tdc?
>Date: Fri, 15 Apr 2005 17:08:55 -0700
>
>Thanks for your replies all. Your responses confirm that I have been
>indeed doing it right. So I'm a bit confused as to why if I set #1 at
>TDC and set the valves, then when I go to do #2 why does #1 have a
>significant amount of clearance again? Does this indicate a cam
>problem? I guess I'm just getting frustrated becuase I've been tweaking
>this about 5 or 6 times now to get it right and it just doesn't seem to
>want to come together. The only time the car runs well and smooth is
>backed off to .006", but it loud as hell (relatively). If I zero them
>out (hot with the lifters pumped up), my car starts fine but begins to
>run rough and make odd noises out the tailpipe after sitting a while.
>If I turn them in past zero, the car will barely start and runs like
>crap (but quiet as you could want). I know my lifters are bleeding off
>too fast and getting squishy in a hurry. The car has 160000 miles on it
>so I imagine the lifters could do with a replacement anyway, I'm just
>also curious about the cam. I can live with the valves clearanced, but
>I sure would like to have my car sound quiet like it should... BTW my
>heads are new (yeah I should have changed the lifters then.. I know).
>Also what's the P# for the collapsable pushrod tubes at BD, I see a
>couple different ones each time I search?.
>
>-Nate
>'84 Frustralia
