datsun-roadsters
[Top] [All Lists]

Re: valve seals

To: Hoon Kim <hoon@pixar.com>
Subject: Re: valve seals
From: "Patrick J. Horne" <horne@cs.utexas.edu>
Date: Thu, 29 Jun 2000 13:22:56 -0500
1600's are much easier to put seals on than 2L engines.

Before you do anything about the valve seals it would be a good idea to check 
to see if
there are any other items that should be addressed at the same time.  Check the 
compression
on the engine, both wet and dry.  I there is a low pressure see if it is 
because of a bad valve,
or bad ring by running compressed air into a fitting screwed into the spark 
plug hole and
listening for air escaping from the exhause or carb, or crank case.  If you 
haven't checked
the rod bearings lately, or know that they are fine, drop the pan and check 
them too. 

There are two ways to replace the seals.  If everything else is in good 
shape,you can replace
the seals with the head on the car.  If you need a valve job, or rings, pulling 
the head for
work would be the best way.

Assuming you don't need anything else, continue here.

Before you take the engine apart it would be wise to get the necessary tools 
and parts!
you will need the valve seals (8), probably a valve cover gasket, a valve 
spring compressor
amd a means of holding the valves closed while you take the springs off.  The 
spring
compressor will need to be the type that can be used with the haad on the 
engine, rather
than the large "C" shaped jobs that are used when the head is off.

Disconnect the battery and remove it to get it out of your way.  Remove valve 
cover and 
remove the rocker shaft.  Do not just remove one nut, then move on to the next, 
but
but loosten all of them a little at a time until they are not holding the shaft 
at all.

Remove the spark plugs.  

Retain the valves on one cylinder using air or a rope in through the spark plug 
hole.  Make
sure you keep one end of the rope outside the engine so you can get it back 
out!  Turn the 
engine over by hand until the rope is pushed tightly up against the valves.  
Compress the 
springs on the valves for that cyl and remove the retainers.  Remove the 
springs, and
retainers, being sure to keep them associated with the parts that came off that 
valve,
as well as which valve they came off of.  Do one valve or cyl. at a time to 
reduce confusion.
Remove the top hat seal, clean where it sits and install the new seal, being 
very careful
not to nick or cut the seal on the valve stem.  I ise either clean engine oil 
or Luberplate
assembly lubricant (white grease) when I do this. It wouldn't hurt to check the 
spring heights
as you go to see if any are defective.  Re-install the springs and retainers, 
turn the engine
back a bit and remove the rope.  Move on to the next cyl and repeat.

Re-install the rocker shaft, turning the mounting nuts a bit at a time until 
they are
all tight.  Torque them down, then adjust the valves.  Put the valve cover back 
on and
put everything else back on that you removed.  Warm up the engine, set the 
valves again,
and give it a test drive.

If the valves, rings, or bearings need attention, do them and do the seals with 
the head
off of the car.

Good luck.

Pat



-- 
- Support Habitat for Humanity, A "hand up", not a "hand out" -
Pat Horne, Network Manager, Shop Supervisor, Hardware Guru 
CS Dept, University of Texas, Austin, Tx. 78712 USA 
voice (512)471-9517, fax (512)471-8885, UUCP:cs.utexas.edu!horne

<Prev in Thread] Current Thread [Next in Thread>