Roadster Rhinoplasty, Part III

Wrapping up the track nose for the Project Potvin roadster 

By Ryan Manson * clampdowncomp@gmail.com

One of the most exciting aspects of any project is when it really begins to take shape and form and begin to actually look like something. For the past year or so, my ’29 roadster has slowly begun to look like a car. Starting with two halves of an original roadster body and a set of drawings on my shop floor,  I built a custom full tube chassis, mounted the engine, trans, and suspension, and reunited the body. It’s slowly taking shape, but still has yet to actually look like a car due to the lack of wheels and tires and any front sheet metal. But the latest development in the build is hopefully going to change all that.  

In the previous story, we started the track nose for the front end of the Project Potvin roadster and finished with the two halves hammered out and ready to be welded together. We also covered how the initial shape was developed using a buck made  from  the front dimensions of the ’29. This told us everything we needed to know to get the shape desired and the dimensions necessary to clear the front frame horns and suspension items. And so, with buck in hand, I headed out to  Elgin, Illinois  where the first half of the track nose was fabricated by Sam Waltermire  at the Roadster Shop.  

An interesting thing happened once the two halves of the track nose were joined together; the shape became very apparent. Whereas before no matter how hard you’d squint or imagine, there was a sense of unsuredness about what the finished product would look like. Once those two halves were joined however, it was very obvious as you walked around it the  shape that it was taking on and thankfully it was looking good. I’ve heard horror stories about track noses  and how guys have built two or three before finally getting it right and to say I was a bit nervous right off the bat would be putting it nicely. 

All in all though, once the halves were welded together, it really looked good. A pie cut was taken from both the top and the bottom to get a more streamlined shape, but that was a very minor hiccup and more of a tweak than any kind of major modification or mistake.  Once Sam welded the two halves together and knocked down the weld bead, it was treated to some more time in the planishing hammer, perfecting all the high and low spots before it was crated up and shipped out. 

With the nose in hand, it was mocked into position on the car and many hours were spent studying the lines of the front end. The hood lines looked like they’d flow from the cowl into the nose as expected and some notching would be necessary to clear the suspension as well but other than that, everything seemed to gel perfectly. An inner structure will be fabricated to  support  the hood and nose off the frame and will also serve to mount the radiator over the axle, inside the nose. To ease installation and removal of both the hood and nose,  Dzus  buttons will be used to fasten everything into place. A grille shell will also be fabricated and fit into the front of the nose to allow air flow through the radiator and into the engine compartment. There’s lots more to come, but for now, check out the final installment of Roadster Rhinoplasty. CC

Sources:
The Roadster Shop  
(847) 949-7637
www.roadstershop.com 
When we left off last time, the two finished halves were installed on the buck and clamped securely in place, waiting to be united.
The two halves slightly overlap and need to be marked and trimmed to fit. Before that though, hash marks were made to help orientate that two pieces back together once they’re trimmed.
A scribe is then used to mark where the one half overlaps the other. The larger of the two sides will be trimmed to meet the other.
A pair of shears is used to trim away the extra material.
Once the excess piece was trimmed away, we noticed how much thicker that area was due to all the shrinking necessary to shape the front of the track nose. Compared to a piece of the original gauge aluminum, the worked piece is about .030-inch thicker.
Panel clamps are used to hold the two halves together while they’re tacked. The panel clamps align both pieces edge to edge and surface to surface leaving a .040-inch gap for full weld penetration.
The front most section is tacked first, alternating from side to side, working towards the rear.
Once the two halves were tacked together, it was decided that the profile needed to slimmed down somewhat. A pie-cut will be removed from the section marked and rejoined to the other half.
Here’s the inside of the track nose after it’s been welded. Notice all the marks from the planishing hammer. Also notice that the weld seam penetrated fully through the aluminum skin.
The next step is to knock the weld seam down and begin the finish work on the nose now that it’s one piece.
The welding process caused the aluminum to warp slightly along the seam so a few minutes in the planishing hammer is necessary to get the crown nice and even.
A stepped edge was fabricated along the entire back side of the nose so the full hood has something to engage, much like a stock grille shell has.
Here’s the finished track nose and buck. A mock opening was marked on the nose to simulate the grille that will eventually rest there.
With the nose complete and mocked in place, the front end of the roadster is starting to come together. The lack of a front wheel or any front suspension makes the front end seem extremely long, but with a hood length of 34-inches, it’s only slightly longer than a stock Model A.