I've taken longer bolts, cut the heads off, grind a slot into the top end
(for a slotted screwdriver) and used them as installation alignment holes.
Put them in, then the gasket, then the head. then you can un-screw them and
put the correct bolts in.
The head is definitely a two guy (person) job, I partially pull the hood to
get better access.
Loose or more correct non torque'd head bolts will guarantee a gasket
failure. Lot of pressure it the combustion chamber.
You've got the head off, so this tip is moot, but if you have a compression
tester and shop air, you can find a blown gasket quick.
1. put the cylinder in question at top dead center
2. attach the shop air to the compression tester's quick disconnect
(not a lot of pressure same as compression ratio.. 35-70psi)
3. remove radiator cap
4. look for air bubbles
if its blown you'll see bubbles, if a valve isn't where its supposed to be
you'll hear hissing from the exhaust or intake manifold.
Jon P
-----Original Message-----
From: Rob J. [mailto:rjjmsj@earthlink.net]
Sent: Saturday, January 19, 2002 2:45 AM
To: _Old-chevy-truck; _Oletrucks
Subject: [oletrucks] Overheating solved - head gasket
help now needed
Ok, pretty sure my problem was a blown head gasket. Pulled
the head and the
gasket seems to indicate that that is the case, but I don't
have a lot of
experience reading signs. Nice clean copper color except
between #2 and #3
and between #4 and #5. There, the gasket was a dark
brown/black color,
which I would guess would indicate something was happening
there, that
wasn't occuring elsewhere, ie. maybe either combustion gases
causing the
darker color, or possibly water stains? I'll be taking the
gasket with me
tomorrow to the machine shop when I take the head to have it
magnafluxed and
checked for flatness, and have them see if they can read the
gasket to tell
me what might have been happening. Not really any signs
that water was
getting into the chambers, as al cylinders had about the
same amount of
carbon buildup...so I suspect, the problem was the
combustion gases getting
into the water jacket. I finally saw the bubbles (lots) in
the rad. When
the radiator is very full, you don't see them...but if the
level is down
about 1/2 - 1 inch, they are very apparent. I guess I would
simply have
been checking with the rad topped off.
However, I think I need some suggestions on the best way to
replace the new
head gasket. That head is very heavy, and since there are
no alignment pins
to hold the gasket in place while I try to manuever the head
onto the block,
does anyone have any useful suggestions on the best way to
try this with the
engine in the truck...last time I did this, the engine was
out...much
easier. I think I may try to position my body in the engine
compartment in
order to be able to lift the head onto the block. Very
difficult to do from
outside the fender (too heavy to hold the head with arms
outstretched, and
not really very easy to position two people on opposite
sides. Just getting
the head off was difficult...and that was when it really
didn't matter if
the head gasket was maybe scratched or slightly damaged in
the process. The
reverse will need to NOT damage the head gasket in any way,
so if anyone has
tried this with the engine in the truck, please let me know
how you did it.
Oh, one more item. When I removed the head bolts, I was
very surprised that
it took very little force to loosen them...seems it should
have been
somewhat difficult, right? I know I never retorqued them
after the first
500 or so miles as I was not aware at the time I rebuilt the
engine that I
should have done that, and then just never did as everything
seemed to be
fine until just recently. Obviously, if they were a bit on
the loose side,
that certainly would have helped to lead to a blown head
gasket. So, what
I'm wondering, is the force needed to loosen them not
necessarily gonna be
all that much? I will be chasing all the threads, both in
the block, and of
the head bolts.
Is it possible to still get replacement head bolts from a
FLAP? I almost
torqued a head off one the last time I did this, and don't
want to risk that
again if I can help it. How safe is it generally to reuse
head bolts?
Finally, I believe that only the number 1 bolt enters the
water jacket...is
that correct? (By #1, I'm referring to the center bolt,
nearest the outside
(passenger side of the block). So, if correct, then that is
the only one I
would need to put a dab of RTV on the threads, right?
TIA,
Rob
oletrucks is devoted to Chevy and GM trucks built between
1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|