<VV> Where do I go from here?

[N. Joseph Potts]

On the 140s, it is indeed the intake valves that fall out of the heads
first. However, the cylinders in which this happens first are commonly #5
and #2. #6 IS a candidate for this misfortune, but if you really get good
compression in that cylinder, I'd be inclined to doubt that diagnosis.
     Something to try if you run out of other ideas: move the piston to the
top of its travel (to keep the valve from falling into the cylinder), and
take the spring off the valve. Now check the valve sleeve for being securely
held in the head (they CAN work loose, and will cause clatter without full
loss of compression), and while you're at it, evaluate the state of wear of
the valve in its sleeve.
     If the plug in this cylinder is fouled and the plugs in the other
cylinders are not, it could be a sign of excessive wear at this point. If
they're all, or most of them, black, direct your attention elsewhere until
the clatter problem is solved. I've never had a lifter fail, but of course
others have.
     A suitable tool for removing valve springs is sold at auto-supply
stores (a chunk of metal). Anything for overhead-valve GM engines for use
with head on the engine.

Joe Potts
Miami, Florida USA
1966 Corsa coupe 140hp 4-speed with A/C

-----Original Message-----
From: virtualvairs-admin@corvair.org
[mailto:virtualvairs-admin@corvair.org]On Behalf Of Jack & Elaine Kean
Sent: Sunday, December 12, 2004 9:30 PM
To: virtualvairs@corvair.org
Subject: <VV> Where do I go from here?

I purchased my current car (1968 Monza Convertible
with 140, 4 speed, 3:27, Corsa dash) last summer. It
had around 2000 miles on the current rebuilt engine.
The motor ran fine, with good performance and very
little oil consumption. The only noticeable problem
was the excessive valve clatter, which I attributed to
incorrect push rod lengths, when I purchased the car.
Since then, I put around 1000 city miles on the car
with no real problems, except the engine seemed to run
hot, even though the cylinder head temperature never
read much above 400 degrees.

One afternoon, the clatter became noticeably louder on
the drivers side, so I attempted to adjust the
valves. This was an attempt to see what was going on.
This is also when the real problems began. The
noisiest valve clatter seemed to originating from the
#6 intake valve. I listened for a while, and then
adjusted those three cylinders while the engine was
running. However, the clatter was still there. I then
pulled the rocker arm and saw a fair amount of wear on
the top of the valve stem, indicative (I think) of
push rods that are too long. After I reassembled the
rocker, and readjusted it, the engine runs rough, and
clatters. It occasionally backfires.

I have not driven the car since, and wonder what the
most reasonable course of action would be.

-       Should I determine the correct pushrod lengths,
install the proper pushrods and see what happens?
-       Have I messed up this lifter?
o       Should I simply replace it and see what happens?
-       Do I have a dropped valve seat (the miss is not
constant, and all three cylinders have reasonable
compression when I checked them last)?
-       The sparkplugs are sooty. Could I have fouled them
because I let the car idle so long?
-       Or ???
I am only hesitant getting into this engine, because
it has been 14 years since I owned one of these cars.

It is a kick to drive, and I only want to get it back
on the road soon.

thanks

jack kean
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