Knuckle head gaskets

[shinedogg]

The MoCo always used copper head gaskets until the war time restrictions on copper during WWII came into effect. It was at that time that they started using asbestos gaskets. Copper gaskets can be annealed and reused. A thin later of aluminum spray paint makes a great sealer.

On a side note I recently bought a 1921 Ford Runabout. I was surprised when I pulled the head and found an original FORD script copper head gasket still in use. Being as it is only 99 years old I am going to reuse it.

I would too Chris! Might even make a necklace out of it!

[T. Cotten]

Yes 1000cc OEM was copper

Thanks, Duffey!

I wonder why...

Seriously.

...Cotten

[duffeycycles]

Yes 1000cc OEM was copper

[Rubone]

All the 1000 cc Sportsters were copper and that includes two different hole patterns.

[T. Cotten]

An early sporty collector just told me that 900 sportys originally came with composite gaskets not copper.so composite on cast iron heads

Did the MOCO switch to copper later, Duffey?

I let very few Sportsters in the door, as they were molested and sick, but ran very thin copper.
And I believe the aftermarket kits were usually copper.
There's a quartercentury-old set in my inventory somewhere.

An auto speed shop I worked at had me milling "O-ring" grooves around cylinder bores for copper wire, and presumably ran no gaskets.
(But they didn't have to run long before the next tear-down.)

Would no gasket conduct more or less?

Sorry I have so many questions...

...Cotten

[duffeycycles]

An early sporty collector just told me that 900 sportys originally came with composite gaskets not copper.so composite on cast iron heads

[T. Cotten]

Sorry Cotton,I did not finish the sentence..edited
I use the asbestos on aluminum
I have seen the imprint in aluminum as well

Be careful, Duffey!

You'll get an edit addiction like mine.

Another arm-chair-engineer'd reason for the erosion:
Aluminum and cast iron have very much different thermal expansion coefficients.
Hard copper between becomes 'cutting edge'.

....Cotten
PS: Just another reason why Knucks were the pinnacle of classic American motorcycle design.

[duffeycycles]

Sorry Cotton,I did not finish the sentence..edited
I use the asbestos on aluminum
I have seen the imprint in aluminum as well

[T. Cotten]

Copper for aluminum
K-models had no gasket?
Sporty was copper..I think

Copper for aluminum, Duffey?

My autopsies showed they "imprinted" into the head,
Whether beaten into them by a million million compression strokes,
or by dielectric something or other.

Good point about the aluminum Ks using just paint.
After all, if you need it to seal copper, why bother with the copper?

Conductivity?

....Cotten

[duffeycycles]

Copper for aluminum causes issues on some 45" because of narrow area near the motor mount.
K-models had no gasket?
Sporty was copper..I think

[T. Cotten]

Copper for cast-iron, Folks,..

And composite for aluminum for all marques was the way I was raised.
(Too many mentors to remember.)

So that explains my original question, as we are talking Knuckles.
Were OEM iron-head Sportsters' copper?
(Gotta ask, because they were all trashed long before they reached my benches.)

....Cotten
PS: I preferred composite no matter what. Cost, sealability, and insulation seems to make most sense.

[duffeycycles]

From Chris:The MoCo always used copper head gaskets until the war time restrictions on copper during WWII came into effect. It was at that time that they started using asbestos gaskets. Copper gaskets can be annealed and reused. A thin later of aluminum spray paint makes a great sealer.
The 1940 parts books show11-36,cylinder head gasket for cast iron head 45" 1936-1940
11-39 for 1939 WLDD & 1940 WLD, aluminum heads
The asbestos/composite gasket was for aluminum head 45" models, starting with the first 45" aluminum head models
11-39 does not appear in the '39 book so maybe problems appeared in '39 so they made the asbestos then
No mention of different gaskets for ULH UH models

[T. Cotten]

It sure didn't help the 'corrugated' gaskets at all, Mike!

Paint's good for composite gaskets, as it makes them much easier to clean off next time.

...Cotten
PS: Irregularities like tool mark are good. They hold the gasket.
Irregularities like the common warpage of flatties over the intake port are more than I would like to trust to a band-aid.

Oh yeah, aluminum OHVs suffer from that too!
Knucks not so much.

PPS! Heat-Paint upon vintage productions of asbestos or cardboard-like head gaskets should be worth the gamble.
Please do NOT use it upon modern adhesive-impregnated gaskets such as from my preferred supplier, JAMES.

That means manifold gaskets, too.

[ihrescue]

That's great info, Chris!

But why should they need a sealer?

Insulation?

Why didn't they go back, when it was surplus?
Just wondering, since they obviously went to ordinance brass for manifolds and stuff.

....Cotten
PS: I couldn't get some 'corrugated' (probably Eversure) coppers to seal, with paint of course,... cold. Never fired.

Tom: One reason I have heard for using the spray lacquer with suspended aluminum dust in it is that the aluminum fills in and helps seal any irregularities between the head gasket and the head. A friend of mine who had been a H-D master mechanic for 30 some years swears by it to give that extra sealing edge. Of course the use of a soft metal like copper and torquing was also probably to account for the irregularities in cast iron. It would be interesting to know if H-D ever had a service bulletin to recommend this procedure.

Mike Love

[ihrescue]

The MoCo always used copper head gaskets until the war time restrictions on copper during WWII came into effect. It was at that time that they started using asbestos gaskets. Copper gaskets can be annealed and reused. A thin later of aluminum spray paint makes a great sealer.

Chris - When I saw your mention of annealing a copper head gasket I did a browser search on the keyword "anneal copper head gasket." One item that turned up I think is interesting in that this Brit bike enthusiast had even new copper head gaskets that were somewhat hardened and he recommended even annealing new copper head gaskets. I for one would like to hear how others react to his observations and comments. Here is the link https://www.classicbritishspares.com...ys-anneal-them

Mike Love