A Grille for the Indy Car

The grille shells for the Studebaker Indy cars were built in the Rigling or Dreyer shops in Indianapolis, as was the rest of the frame and sheet metal.  There are no drawings for these parts, but perhaps they were made from 1931 President grilles.  Anyway, after staring at the fronts of many Studebakers of the period, I finally decided to use one of those.  Fortunately, when I was at the International Meet in Cedar Rapids, Barry Hackney had one for sale - and Mike Cleary's blue #18 car was parked inside the same building, only a few feet away.  This allowed me to compare the two and satisfy myself that this was as good a starting point as I was going to find.

#18 grillestock 1931 President grillegrille cut in half

I also had a number of measurements taken from Bob Valpey's #37 car for the height and width of the Indy grille shell.  It was clear that a lot of cutting and re-welding was going to be needed.  The first thing I did was to saw around the radiator fill hole at the top of the shell, then I removed about 3/4 inch from each side so that the shell would fit between the frame rails.  Since the shell was pretty badly rusted already, I didn't feel too bad about cutting it up.

The distinctive Vee shape at the bottom was made by twisting the bottom ends out and adding a piece to form the shape, including a hole for an engine crank - not that one ever got used on the Indy cars.  Once the width and bottom shape were right, I cut the shell  in half again, this time top-to-bottom, and took out 10 inches of height.  It was a little difficult to match up the profiles and smooth the transition while holding the general shape, but it worked.  At this point, all of the welds were tack welds.

grille tack weldedwelding the grille, rear view


The original cars have a pan at the bottom of the shell, perhaps for smoothing airflow, so I fabricated one following the shape and dimensions of the one on the #37 car.  This pan stiffens the assembly a lot and helps to hold the shape after all of the twisting and welding that was done to the basic shell.

grille bottom pan

There is a rather elaborate rosette around the crank hole that was made from a separate piece.  It has two raised semicircular grooves.  I machined an aluminum plate with the grooves as concave surfaces, then bought some thin brass sheet and some thick, hard urethane pads.  The aluminum die was placed inside a 4 inch steel tube, then a brass disk was loaded with a urethane pad and a thick steel "pusher" on top.  The assembly was placed in my hydraulic press at maximum pressure.  The urethane behaves like hydraulic fluid at these pressures and forced the brass into the shape of the die.  Then the brass part was placed on a thick hard-rubber pad and a steel bar (2"x2"x1/8" angle iron) with a slightly rounded edge was used to fold the brass disk 90 degrees to match the Vee of the grille shell.

grille rosette die  grille rosette bending

At the top of the grille shell is a tab with the Studebaker wheel logo as used on the production car grilles.  A tag of sheet steel was cut to approximately the size and shape required.  A hardened steel impact wrench socket was used as the form to curl the edges over, and a body hammer was used to tap the lip into shape.  Above the tab, a raised bead was formed by a lot of welding and grinding.

The next task was to form the vertical bars of the grille.  It isn't clear where the concept of these bars came from, Studebaker or the Dreyer/Rigling shops, but the style can be seen in the 1932 Rockne grilles where there are two angled bars.  Again, following dimensions from the #37 car, I had a local sheet metal shop fold thin strips of steel about 2.7 inches wide into a Vee.  A 3/16" steel rod was placed in the Vee and a large sheet metal brake was used to pinch the Vee closed around the rod.  The rod was pulled out, leaving a round tube about 1/4" diameter with a 1" deep web behind it.  About 24 of these were made to form the grille design.  The strips were cut to length and welded in place.  Along the way, the all of the joints in the shell were fully welded and ground, and excess holes filled with patches.

grille shell weldedgrille ribs and rosette

Photos of the Studebaker assembly shop in 1932 show the prototype 1931 car (#37) with the four later cars being put together,  Perhaps for the benefit of the pictures, the cars are all wearing the "bird" radiator cap, as used on the production cars that year.  Of course, for racing, the birds were replaced by flat, smooth radiator caps.  However, I do have a bird to use for shows.

The grille shell still needs to have the brackets welded to it to hold the radiator and attach the shell to the chassis.  Then it will go out for finish polishing and chrome plating.

indy cars in shop 1932 with bird rad capsfinished grille with bird cap