From: John De Armond
Date: Apr 1992
X-Source: The Hotrod Mailing list
Subject: Re: copper head gaskets

>I was having problems blowing head gaskets on my top nitrous setting
>(225 hp) so I tried some soft-copper head gaskets from Warrior Racing.
>I have a .060 over Pontiac 400, and Pontiacs are a bit lacking in number
>of head bolts (4 per cylinder).
>  At any rate, the copper gaskets blew began leaking badly within miles, blew
>the radiator cap off from the pressure. I reinstalled but this time sprayed
>copper-kote. They blew in about 20 miles that time, as in combustion
>pressure getting into the cooling system. My block could not be O-ringed as the
>shops involved said there wasn't enough room between the bores. The 3rd time
>I tried laying 0.010" copper wire in circles around the bores, this cut into
>the head gaskets and stopped combustion leakage, but now the coolant and oil
>passages were leaking into each other.

At the Southern Nationals this weekend, I strolled into the pit of Joe
Amato after he blew in the semi and looked at a set of heads laying on
the table. (hey you can get away with anything if you look like you know
what you're doing.  There is a very thin, much thinner than I've ever
used, stainless steel O-ring around each combustion chamber.  I would
guess the wire to be no more than 18 gauge.  I did not see a joint so
the O-ring appeared to be manufactured as such instead of just wire laid
in a groove.  It almost looked like the O-rings had been pressed into
the aluminum head.  On one side of the chamber the ring had to come to
within 0.010-0.015" of the bore.  All were identical so this was not
an accident.  Of course he DID blow a gasket in the semi.... :-(

>  I finally gave up and went back to Fel-Pros. Does anyone have experience
>with copper gaskets? In retrospect they really seem like a bad idea since there
>are no higher local pressures around the oil/water passages or bores. Seems
>like they ought to work great with O-ringing, if the rest would seal up.

>  Or alternately, got any good tips on sealing Pontiac heads (or other) under
>extreme pressures? I tried H-O's trick of using stock steel gaskets with wire
>laid in between the bores, but stock metal gaskets do not have valve reliefs
>cut into them as my block does, and the result is gasket hanging out in the
>combustion chamber which soon burns through.

I went through hell and back trying to keep the heads on my 35 psi boost
Datsun Z-car engines.  Like yours, the head is a bit shy of head bolts.
Among the things I've tried, solid copper headgasket, drilling the block
and head for 1/2" chrome-moly studs torqued to 200 ft-lbs and a wide
variety of elixirs.  The copper head gasket worked if annealed dead soft
after each use and if used with O-ringing.

Then I decided to use science :-)  My final solution required little work
and has been 100% reliable even in the face of engine wrecking detonation :-(
There are two steps involved.  This technique presumes an aluminum head.
Should work on iron heads but I've not tested it.

The first involves a standard FelPro gasket. Get some 16 ga 304
stainless wire.  heat a length of it red hot and allow to cool
slowly until it is anealed.  Carefully scrap the gunk from the
head side of the combustion chamber sealing ring on the gasket.
Bend the  stainless wire into a circle the radius of the center
of this sealing ring. Using a superglue wire tacking kit
available for <20 bux from electronic supply houses, tack the
wire to the center of the sealing ring.  The  ends may either
butt together or better, slightly overlap.  The wire tacking kit
contains superglue and an accelerator that makes the glue set on
contact.  It is designed for tacking ECO wires to circuit
boards.

Step two.  Prep the block and head.  Both should be freshly
decked and clean. Obtain a common electric engraving pen of the
type used for anti-theft markings.  Turn it on full stroke.  The
tip must be very sharp.  If not, sharpen it using a standard
green carbide wheel.  Slant it at a 45 degree angle away from
the direction of travel.  Imagine you're using it to plow up a
furrow of metal from the head or block.  Use a very loose grip
so the tool can bounce.  Rapidly stroke across the gasket
surface.  The tip should bounce off the surface of the metal 120
times a second.  Properly done, it will raise little divots
about every half millimeter or so.  The top side of the divot
will be very sharp. I test my technique by dragging a shop rag
across the surface to see if the divots pick off lint. (boy I
wish I could include a drawing!)  Treat the entire surface with
this technique.  When finished, the surface should feel like
coarse sandpaper and have a sparkling sheen when viewed in
bright light.

                    /  <- engraver
				  /
                /   <<<- direction of travel.
---------------------------- <- deck surface

How it works.

The stainless steel wire bites into the gasket with tremendous clamping
force and at the same time partially embeds itself into the aluminum
head.  The little divots dig into the gasket material and after the
first heatup, have gasket material extruded into them. they form an
interlocking matrix that grips the gasket with great tenacity.
In fact, the only downside involves the fact that the gasket is clamped
so tightly that it becomes difficult to remove.

I assemble the head using as much torque as I can get away with.  On
Z motors, I know this is about 100 ft-lbs (60 is spec.)  I let it soak
awhile and loosen the bolts and torque to spec.  This ensures the
wire gets a good bite.  I warm the engine by running it on the test
stand, let it cool and loosen and retorque again.

Hint for quickly warming an engine in the shop:  I use the once-through
cooling method.  Garden hose in the pump, waste water out the thermostat
and out to the drain.  Instead of cold water, connect the hose to
the water heater and set the thermostat to 180 degrees.  This will rapidly
warm the engine before you crank it the first time.  Makes it a lot
easier to crank.

John

From: John De Armond
X-Source: The Hotrod Mailing list
Date: Jun 1992
Subject: Re: No head gasket wanted

>> I want to increase the compression on one of my small block engines.
>> the easiest method under consideration is to do away with the head
>> gaskets.
>> John, Dave, have either of you ever tried this or know something about
>> it?
>>
>You've got me on that one!

Me too.  I tried just the opposite once.  I needed to drop the compression
significantly on a high boost turbocharged Z engine.  I fabricated an
aluminum head spacer about 0.080" thick to the pattern of a head gasket.
Many hours on the milling machine.  The plan was to O-ring the spacer
on both sides and use the combination of extremely flat surfaces and
some magic goop to seal the water and oil passages.  Never worked.
The thermal expansion difference was too much to deal with between the
iron block and aluminum.  I tried dead soft copper too and that
similarly failed.  You have any idea how long it takes to mill a
head gasket from copper? :-(  I guess Felpro is right when they refer
to gaskets as "sealing systems."

Magic goops tried included RTV, Loc-tite form-a-gasket, Permatex aviation
seal, some high-zoot radiation resistant nuclear grade sealant used in
nuclear plants and containing lots of powdered nickel, silver paint (one
of the longer lasting ones.) and probably some stuff I can't remember.

I'd just mill the head and use the Felpro wire sealing gasket (someone
pop out a part number :-) and have a stone cold reliable setup rather
than "innovating" and having it repeatedly failing.

John

X-Source: The Hotrod Mailing list
Subject: Re: O rings I
Date: Thursday, Aug 18 1994 14:53:17
From: John De Armond

>>From dave.williams@chaos.lrk.ar.us (Dave Williams)
>
>
>-> >  How do you cut a head for O-rings?
>->
>-> something like a flycutter?
>
> Best as I can tell, that'd be it.  The problem is, it'd be a bitch to
>make sure you're properly centered over the bore.  I was just hoping
>there was an easier way I wasn't smart enough to see offhand.

Jigs for doing heads are available from the usual sources but I
do not recommend doing the head unless you like to re-do it every time
you have the deck resurfaced to re-true it.  For aluminum heads,
that would be every removal.  Since the deck rarely has to be trued,
one grooving job lasts a long time.

John

From: John De Armond
Date: Wed Apr 3, 2002  11:22 am
Subject:  Re: [megasquirt] Megasquirt on turboed 4 cyl DOCH engine????
X-Source: The Megasquirt mailing list

On Wed, 3 Apr 2002 11:21:36 +0100, "Glenn" <g.stile@b...>
wrote:


>I would also recommend that you o-ring the block on that engine of yours, 
>ive built allot of turbo systems for various engines and £ per reliability 
>its defiantly the best mod you can make, 
>

Absolutely! Unless you need the head gasket to be the fuse that blows
before something REALLY expensive breaks.

I'll toss out a little trick that I used in lieu of conventional
O-ringing back when I was building hot Datsun 240Z turbo engines. No
one in my area was set up to do block O-ringing on foreign engines and
I didn't want the heads done. I came up with what I think is a pretty
ingenious substitute that worked up to about 30 psi of boost on this
engine.

In a nutshell, what it involved was superglueing 0.030 stainless steel
welding wire to the fire ring of each head gasket cylinder opening
after removing the "special coating" with solvent. This wire was
placed on the aluminum head side of the sandwich and was pinched by
the iron block and the 1/2" allen-head cap screws that I replaced the
puny 8 mm head bolts with. When the head was torqued down, the wire
embossed the aluminum head enough to become rigidly fixed while at the
same time compressing the fire ring and gasket underneath very
tightly. Once I got the block/head joint absolutely stationary with
the large fasteners and about 130 ft-lbs of torque, this setup was
stone-cold reliable.

My technique is as follows. Carefully uncoil the stainless steel
welding wire from the roll so as not to kink it. Wrap it several
turns around a piston (or other object) somewhat smaller than the
cylinder so that when released, it will form a coil about the diameter
of the cylinder, only a little larger.

Cut the wire into single coils with about a half inch of overlap
initially. Carefully position the ring on the fire ring of the gasket
(datsun factory gaskets had a sticky goop on the ring that helped hold
it in place.) and make the ends overlap. With an Exacto knife or
equiv, mark across the two ends somewhere along the overlap. Snip the
wire with flush cutting dykes a fraction of an inch outside the mark
on each end, then with a jeweler's file, bevel the ends at a 45 deg
angle so that when the ends butt together, the fit smoothly and make a
ring of the diameter to fall squarely on the midline of the fire ring.

Next, remove the special goop from JUST the fire ring with solvent and
a Q-tip or equiv. Lay the wire on the fire ring and tack it down with
super glue every half inch or so. Use accelerator to make the glue
set instantly. Make sure the ends butt up against each other and tack
the ends together with superglue. 

Repeat for each cylinder, then assemble the engine normally with the
O-ring facing up against the head gasket. If the head is not
positively located with dowels like the Datsun head is, be very
careful to place the head straight down on the block and avoid any
lateral movement which could dislodge the wires. I recommend making
several passes when torquing the head bolts down to make sure the wire
embosses the head evenly.

I found that if I was very careful, I could remove the head and then
reuse the gasket a couple of times before it got beaten up enough to
start leaking. I NEVER blew a head gasket once I started using this
technique.

Obviously this is a time vs money tradeoff to the extreme. Seems I
always had vastly more time than money :-) Ditto for my customers.

John