Big Bore question

[dukekleman]

Cotton I explained in my first post exactly what I ve found that causes a head gasket to fail. One head gasket or two head gaskets, doesn't matter. Those items I listed apply.

No dancing on my end. Just conversation on each topic of change that has been brought up. My thought was that I was helping, maybe I'm not???

[T. Cotten]

In order to achieve gasket sealing longevity, I highly recommend that you re-torque your gaskets early and often until you noticed them holding torque and settling has stopped.
Otherwise you will have problems later...

Really Duke...

How do some Folks get away without a retorque (as prudent as that may be?)

Tain't the fuel, Duke.

Its too much air.

....Cotten
PS: Why did the MOCO bother to redesign something that worked for over three decades?

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[BigLakeBob]

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[dukekleman]

I actually asked that question back then.
The answer I was given was:

"We did it to allow movement during engine growth for expansion and contraction."

I was shown motor growth where they had dial indicators set up measuring the height changes of the engine from ambient temperature to operating temperature. This affected the manifold fitment on a V twin design engine. They still build manifolds that allow this growth today on 2023 models as we know.

[T. Cotten]

I actually asked that question back then.
The answer I was given was:

"We did it to allow movement during engine growth for expansion and contraction."

I was shown motor growth where they had dial indicators set up measuring the height changes of the engine from ambient temperature to operating temperature. This affected the manifold fitment on a V twin design engine. They still build manifolds that allow this growth today on 2023 models as we know.

Doesn't that raise the question, Duke,...

How did the seventy years of American v-twins that came before that, do so gloriously with rigid brass ferrules?

....Cotten
PS: You were half-right with 'fuel', as today's P4gas swells common O-rings, leading to the dreaded manifold leak, meaning more air, thus heat damage:

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The bands suffered more, by my experience, decades ago.

....Cotten

[T. Cotten]

I just purchased a 93in stroker in a 76 FLH. ( My 1st) I had to take off the rear head of due to a blown head gasket. I'm having the head repaired now but being my first stroker, I was wondering if the pushrods are adjusted the same as a 74 ci motor. Also does someone have headbolt torque specs on a stroker? Thanks.

Have you reassembled yet, OWG?

Which manifold design do you have, and does it mate up to the installed stroker head spigots?

You don't want to go through this twice...

...Cotten
PS:

Pushrod adjustment is the same. Headbolt torque is same as stock. No need to overthink it. Stroker just means trouble, not special.

We do need to think about whether you have stock pushrods or not, OWG; Have you stock hydraulics (on the right), or have they been replaced with solids, or some "performance" assemblies?

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(That's when it gets a little more tricky, but still no reason to resent strokers...)