Inverted Vee Conversion

[ffindling]

Another reason for the inverted arrangement used on the DB600 series
engines was gun placement. Designers
of the day felt that having a large caliber
cannon on the airframe's centreline was
advantageous compared to wing-mounted
armament. On aircraft like the Bf109, a
20 mm cannon was mounted inside the
vee of the DB engine. Since the propeller
was attached to a spur-gear reduction
hub, the propeller hub cenreline was
lowered to a point within the vee. The
output shaft of the reduction box on which
the prop itself was mounted was hollow
and open at both ends of the gearbox.
That way, it was a simple matter to mount
the gun within the vee and have the
muzzle of it looking through the hollow
output shaft. While a similar arrangement
could have been done with an upright vee,
the inverted arrangement made for better packaging and service accessibility.

.....Fred