Okay, here we go........
I purchased this car about 18 months ago from the estate of a friend
who had passed away far too soon The original chassis was a 1968
Harold Wilson car built in Kansas. This design represented the state
of the art in Top Fuel racing of the era.
It has since been through many engine combinations, and has been
extensively modified in it's 36 year racing history. After running
the car a few times I discovered major structural damage in the lower
frame rails. I asked the NHRA tech inspector to assess the chassis,
and it was quickly determined that extensive work would have to done
to bring the car into compliance with the latest chassis updates
required for chassis certification for the upcoming season. A new
chassis that could still use all the components from the old car was
the most cost effective solution to the dilemma. A quick search of the
Internet,revealed chassis prices in the stratosphere! The materials
were approx. 30% of the cost of the chassis, labor made up much of the
replacement cost.
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| If I fabricated a chassis myself, I could customize the car to the
drivers, (me) size and fit all the existing components like the
steering box and front axle to the new car. A Miller Syncrowave 180
was purchased to do the tig welding required for the 4130 Cro-moly
tubing used in the chassis construction. I purchased a chassis
blueprint, and quickly determined the design was not suitable for what
I wanted the new car to be. The new car would be of my own design, but
heavily influenced by the 60's design of that era. In short, a blend
of new technology and old school design! As a result, most of the
parts used in the blueprint were not comparable with my plans. |
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To accomplish the fabrication, a few specialty tools had to be
purchased and / or fabricated. A heavy duty hole saw type notcher was
purchased from Pro-Tools to fit the tubing ends together for a minimum
gap. 1 1/4" bender shoes for my shop built one shot style bender were
also purchased from Pro-Tools. |
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| This is a race car in the purest sense. In that fact, all of the
drive line is solidly mounted, alignment of motor, trans and rear end
is critical. An alignment bar had to be fabricated to pass through the
engine main bearing bores and attach to the Currie 9" Ford rear end
that was fabricated for this project. A new motor plate was
fabricated from 1/4" T-6 aluminum plate to fit the new design. In the
process of fabricating the motor plate, the shortcomings of my Chinese
drill press came to light. A need for a higher degree of accuracy led
to the purchase of a used DRO equipped Ex-cello milling machine. This
machine has been invaluable during the construction of this project.. |
   
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I began to research welding procedures for 4130 Cro-moly tubing and
found that the filler rod used for this application is actually a mild
steel rod. Several sources identified ER 80S-D2 as the preferred
filler metal to use. A flex head tig torch and gas lens diffuser are
also recommended for this type fabrication. Welding is done on DC
straight polarity with a 2% thoriated tungsten electrode, 1/16" dia.
ground to a point. Argon is used as the shielding gas.
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Post meeting BBQ...
