Porting and Relieving the Flathead
1 - Porting, or enlarging the intake and/or
exhaust ports in the block.
2 - Relieving, or removing metal to allow
the gasses to enter and exit the combustion chamber.
3 - Boring,
to allow a larger piston.
Not indicated in the picture above, but shown below, is grinding the
valve and seat for greater flow.
to the hot rod the flathead page.