CRAMPTON CUSTOMS
requires that “Members should have a strong faith
in Our Sainted and Benevolent Mother of Blessed
Acceleration.” Amen to that.
Leaving aside forced induction for a moment,
engine modifications include a J grind Andrews
cam, S&S adjustable push rods, JIMS solid lifters and
Ferrea valves and heavy duty valve springs. The bikeruns a remote Holley fuel bowl from a four-barrel
carb due to the original carburettor not being able
to handle more than two psi fuel pressure, which
resulted in flooding.
Currently running six psi fuel pressure, in order to
get the carby to run correctly a remote Holley bowl
and the original carb bowl housing had to be boost
referenced to maintain a correct float level under
boost. A secondary accelerator pump was added due
to a hesitation when cracking the throttle with the
big inlet plenum. So the accelerator pump from the
Holley bowl was utilised with a custom linkage and a
custom made nozzle fitted before the carby venturi.
A Malpassi rising rate fuel pressure regulator
maintains one to two psi more fuel pressure than
boost pressure. For example, 15psi boost=17psi fuel
pressure. This is because the fuel needs to be under
pressure to get through the jets when the carby is
under boost.
The S&S Super E carby emulsion tube was also
modified to accept Holley jets. This was done due
to the Super E jet kit being maxed out while tuning.
The Holley jet kits have many larger size jets avail-
able and the boys found it much easier to tune by
swapping jets rather than drilling the original ones.It’s all about the
mechanicalness.
And this bike
has plenty!