Copper Head Gasket

Anyone ever gotten a copper head gasket to not leak? Or is flame ring and occasional blown gasket only option for a leak free head! Back pressure valve installed! :?:

Copper Coat and silk thread on each side of a copper gasket works - usually.

xbacksideslider said:

Copper Coat and silk thread on each side of a copper gasket works - usually.

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Been there, done that! No go!

I anealed the living daylights out of mine. Sealed excellent, but was a pain to remove the head, and that was only after 100 miles.

Never had a problem with the flame ring type although there were some around that were no good at one time. (Can't remember the details of the bad ones... Were they French? Have to dig through my old NN issues.) Gave several tries on a copper one and gave up. I did do all the cherry red heating blah blah with it.

I put maybe 8K miles on my copper head gasket with no problems. Make sure your head bolts are not coming loose, that's the usual problem with leaky head gaskets. I just put it on with no sealant or anything. I was going to use it again, but melted a part of it trying to anneal it, so used a flame ring gasket I had.

Dave
69S

bwolfie said:

I anealed the living daylights out of mine. Sealed excellent, but was a pain to remove the head, and that was only after 100 miles.

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I wish mine sealed. Tried one more time yesterday with copper coat and dental floss around pushrod tunnels. No go! FYI put zip ties around pushrods to help removal and install!

I have had my head on and off 6 or 7 times. I have never (knock, knock) had a leak or seepage from a copper head gasket. Mapp gas torch just isn't enough to aneal. Acetalene with a rosebud does it real good. Permatex copper coat to seal but not a ton of it. Just a good coating on each side.
FWIW My #1 center bolt is drilled and tapped to 7/16-20 with a socket head bolt and a couple extra foot pound of torque ,35 to be exact.
Last season I had 165 to 170 psi on both cylinders.

I have never made a copper gasket seal more than about a year. They always start seeping a little oil. Tried the thread bit and several different sealers.

The head gasket on my bike is copper only because a flame ring is not available in a 880 bore. I use flame ring gaskets on everything else. They must be retorqued many times and rechecked every year and if that is done they seldom fail.

If you want to insure that a flame ring stays put and is more forgiving to cylinder head torque, then machine a groove around the bore and install a copper wire to lock the gasket in place. I do that on all high performance engines that I build whether it's a copper or flame ring gasket. Jim

I've a bit of copper experience and with All The Types of head gaskets.

1. full annealed copper can be dented with a finger nail and will not support its on weight unless supported, ie: a 2" OD thick walled threaded plumbing hi pressure fitting will sag like wax and distort threads to useless - unless real careful. If you water quench you heat shock it and it internally work hardens to some extent. GLOWING Bright beyond cherry red into sun orange is best, all at once or bit by bit. A Cu gasket can get tweaked by swinging on a wire even. Lay flat on wood or hold still till ready to fit. Torque down evenly in pattern cycles to as much as you can stand then heat cycle and break clamp and reclamp a bit tighter than you though you could stand, ditto till dry joy.

Aluminum as Norton once sold is worst as squeezes into the bore, but seals great.


2. Fake FlameRing, paper like composite with tin foil lip of Cu.
second worse as don't hurt piston and seals good but just won't long.
On second though this may be worse and the combustion blast almost cut through the factory routed fuel line before I pulled over.

My first Norton was a 1971 Commando. One day I'm going down the Hollywood Freeway and the head gasket blew out on the right side. A chunk of gasket hit my leg, cut my jeans, made me bleed.

xbacksideslider said:

My first Norton was a 1971 Commando. One day I'm going down the Hollywood Freeway and the head gasket blew out on the right side. A chunk of gasket hit my leg, cut my jeans, made me bleed.

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You gotta retorque a new head gasket often or risk injury

I'm with Jim (comnoz) on this. I had pretty good luck with the original 750 flame ring gaskets back in the '70s, but you couldn't get them for the 920 cc engines, so we all used copper for them. I o-ringed the cylinders and used a copper wire ring, and that solved the blown head gasket issue, but they still eventually weeped oil, even with the slik string trick, and trying every possible gasket sealer I could find. I eventually settled on Pliobond, a contact cement, as the best sealer to use with the copper gaskets. Ron Wood recommended it to me for my Rotax single, and it worked well enough that I started using it on the Nortons too. Might be something better out there now, but I still use Pliobond.

Jim Schmidt did a no head gasket 850 engine for his monoshock racer that worked really well. He had an o-ring groove around the bore, but also hand cut (with a dremel, maybe?) grooves around the pushrod tunnels and the oil drain back hole, and put small diameter copper wire in the grooves. It really worked, but looked pretty labor intensive. I've often wondered if, with modern CNC mills, we couldn't program them for a similar groove design, and just forget about head gaskets. If there was room around the pushrod tunnels, we could cut grooves for elastomer o-rings for oil sealing, similar to what Rotax does, but there just doesn't appear to be enough room.

Ken

Maybe we should have a poll of how many have succeed in using copper head gaskets and keeping them oil tight VS going with flame ring and the occasional blown head gasket (2 in 20 years for me) :?

bmwbob said:

Maybe we should have a poll of how many have succeed in using copper head gaskets and keeping them oil tight VS going with flame ring and the occasional blown head gasket (2 in 20 years for me) :?

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Hi Bob,

Flame ring for me for the last 30 years with not one failure on '72 and '73 750 engines.

I just ordered a thicker copper head gasket and a copper base gasket from Jim Schmidt, I hope they work OK (it will be a while before the engine turns over :cry: )

Jean

Buy a modern auto gasket for a cast iron block alloy head engine, the good ones are graphite based, to allow for the different expansion rates, and they nearly all have a bead of sealant built into them around water/oilways. The technology being used to make norton gaskets could easily be improved, with out the need for machining oring or fitting dental floss .....

Head and cylinder faces must be completely true when using copper gaskets. Using old head bolts which may have been torqued down many times before, and very likely to be stretched is not a good idea. Its also worth either O-ringing the gasket, or sealing using a smear of Hylomar jointing compound in areas subject to oil leaks.

I too think the flatness of the head mating surface has a lot to do with the success of a copper gasket. I used one long ago after the factory flame ring blew out and it went for 25 years without issues. Even reused it without anealing. But when I replaced it a few years ago I couldn't get a new one to seal for love or money. I'm using a flame ring now, and will retorque regularly.

Hello and a happy new year to all afterwards!

Soon i`ll put the head off to put some new valve stem seals in.
I got a combat with 10.5:1 and use copper gasket.

So how should it be done when i put the head on again:

- Do you after anealing the copper gasket dip it in water to quench it?
So that it expands and seals correctly when it gets hot when engine is running…

OR:

- Do you put the anealed, soft copper gasket on after it cooled down in the air without quenching?

I also want to use some copper or aluminium spray on it for extra sealant.

Is there a more preferable method when using such a spray?

What do you think is the right or the better way?


Have a nice day, chris