Knuckle head gaskets

[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 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]

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]

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]

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]

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

[Rubone]

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

[duffeycycles]

Yes 1000cc OEM was copper

[T. Cotten]

Yes 1000cc OEM was copper

Thanks, Duffey!

I wonder why...

Seriously.

...Cotten

[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!