"It’s a true love for well-maintained
and hard ridden flathead motorcycles."

...some stuff and tools on your old Bobber and ride
some 1000 miles to visit a good friend far away.
Be lucky and let him live deep in the Swiss Alps.
Trip without using Autobahn. You'll find a lot more
fine memories & good karma...

Gasflow dynamics are poor in sidevalve engines.
Removing material between valves and bore,
to allow the gas a more efficient flow,
is an old technique called RELIEVING.
The relieving has influence on the compression ratio.
Use only with High Compression Heads!

For some more efficient flow try a larger Intake.
Enlarging and smoothing the complete intake port,
to get more gas to the combustion chamber,
is an old technique called PORTING.
"That is highly recommended for every tuned flathead engine."