The
size and positioning of the Cummins inline 6-cylinder
diesel, New Venture Gear 6-speed transmission,
and custom scattershield combination required
altering the firewall and transmission tunnel,
and repositioning the seat and driver controls
rearward. This also helped the weight balance
of Project Sidewinder.
The
interior of the Dakota was stripped to a bare shell
to allow for positioning of the new engine and transmission,
and for fabrication of the roll cage for the cockpit.
The engine, transmission and driveline were removed
to allow for firewall and tunnel modifications, and
the fabrication of new engine and transmission mounts.
But first, the entire chassis was strengthened with
the installation of the roll cage, as detailed elsewhere.
It
should be noted that not only would the engine extend
further back in the vehicle because of its length,
the relative setback of the engine/transmission mass
was also desirable because of its weight. This engine
and transmission combination tips the scales at a hefty
1300 pounds (the stock 4-cylinder engine and trans
only weighed about 500 pounds). Lateral positioning
was also considered. The Cummins® engine was installed
one inch to the right of center. This offsetting of
the engine provides additional room for accessories
in the engine compartment. It also provides a little
extra room on the driver’s side of the passenger
cabin while countering the driver’s left side
weight. The center sections of both rearend assemblies
were similarly offset one inch to the right to provide
driveshaft alignment.
Prior
to installing the Cummins inline six and the New Venture
Gear® 6-speed manual transmission, a clutch and
flywheel scattershield was fabricated by Sheldon Tackett
from 15 pieces of .250-inch steel. Each piece was machined
and welded together to form the 360° scattershield,
which bolts to the back of the engine block. The bottom
of the rugged scattershield can be unbolted and removed
for clutch service. Some might question the need for
such a scattershield with an engine that isn’t
likely to ever exceed 4000 RPM, but with over 1200
lb.-ft. of torque available from the Sidewinder’s
modified Cummins turbo-diesel engine, the dual-disc
clutch and flywheel will be highly stressed, as will
the entire drivetrain. The Bonneville rules also require
such a scattershield.
Serious cutting was needed on the firewall and floor to fit the big Cummins
inline six-cylinder engine, New Venture transmission, and the scattershield.
The accompanying photos show the extensive cutting needed to fit the new engine
and driveline. After cutting the firewall and floor and building new mounts
for the engine and transmission, it was time to check the fit of the engine
and transmission. The back of the engine block now resides 8 inches beyond
the original firewall location.
Cutting
and shaping the pieces for the new firewall, transmission
tunnel and driveshaft tunnel was a time-consuming procedure.
The new firewall is located 14 inches farther back
than the original firewall to provide the necessary
clearance. Tackett and Glenn Lirhus fashioned the firewall
and transmission tunnel parts from 18-gauge steel,
which is substantially stronger than the stock 22-gauge
firewall. The heavier metal offers additional driver
compartment isolation from the engine in the event
of an engine failure, fluid leak, or fire. It also
adds structural strength to the body of the truck.
A framework of .75 x .065-inch round steel tubing further
supports the transmission tunnel panels. The driveshaft
tunnel is even thicker 16-gauge steel for extra driveshaft
containment in addition to the dual steel driveshaft
containment loops. All of this reflects Banks’ commitment
to driver safety in the unlikely event that something
goes awry.
With
the firewall moved back 14 inches, the seats, pedals
and steering column also had to be moved back. The
Coleman Machine® throttle assembly was shortened
and mounted to the new firewall. Tackett fabricated
brackets from the roll cage to support the steering
column and the brake/clutch pedal assembly. In this
case, the Wilwood® pedal assembly and seat were
relocated 10 inches rearward, and the steering wheel
position was relocated 5 inches rearward. The stock
steering wheel position was a compromise to accommodate
a wide variety of driver heights, but since all of
the Sidewinder’s intended drivers are at least
six feet tall, the steering wheel was repositioned
accordingly. As this Dakota is the extended cab model,
the new seating location will be approximately as close
to the back of the cab as it would be in a stock standard
cab layout. Having the driver setback 10 inches also
helps the front-to-rear weight balance of the truck. |
