1930s Era Champ Car - new project

The champ car has a number.
It's 6!
That should come as no surprise to any who know me. So to keep my artistic juices flowing I decided to put a "6" on the stone guard. Many photos I've seen of numbers painted on grilles and radiators showed less than great results when somebody painted a radiator or grille screen. That is because the paint does not cover all the surfaces inside the fins or screen and the paint has a fuzzy effect. I decided to mask and paint both sides of the screen to make the number outline crisp. I used a creamy Rustoleum in a spray can.

 

The exhaust pipe needs attention. It needs to have the rear of the outlet skived on a 45 degree cut.

Does anybody know for sure why this was done on many cars? I can think of two possibilities.

First - it looks pretty cool. Many exhaust pipes of the '30s aircraft were sliced as they left the fusalage that way, probably for aerodynamics. Racers may have been imitating that.

Secondly - and more logically - is that a straight cut tube will create a distinct backpressure wave as it hits the opening and reverberates back toward the engine. If this reverse pressure pulse hits at the wrong time, RPM wise, it could create a flat spot in the engine's torque curve, To mitigate that effect somebody sliced the exhaust at an angle so the pressure pulse got dissipated from no distinct tuning length of the pipe. If it worked then other racers may have done a monkey-see-monkey-do copy job and it got used elsewhere. This is purely conjecture on my part unless somebody can set me straight.

I don't have a good machine to make the 45* cut so I decided to lay out a path on paper to trace and use a cutoff wheel to do it. I decided to shorten the pipe a little too. If I ever back the car into the wall I do not want the exhaust pipe to be the first thing to hit. I made a paper pattern and stuck it on the pipe and cut the angle. Then, using the same pattern I laid out three attachment points for mounting screws and three additional holes at the rear to hold the muffler insert. Finally I tapped the muffler insert for three 8-32 screws and fastened it inside the pipe with vibration proof (troicho-centric) screws.

Now I can drill the front of the pipe to join it to the header and then weld on the heat shield for the driver.

 

I'm tired of looking at the cardboard engine cover. I'm going to skin it in aluminum, starting with the side panels.
I made the passenger side. I had made a set of louver dies for my DiAcro press so this looked like a good place to use them. I wonder how much 42 louvers cost these days?
I also drilled and tapped the header collector three places to hold the exhaust pipe on. That job did not go well. I broke the tap off in the stainless header. Now what? I couldn't access the broken off tap from the inside. Fortunately the gods of rodding smiled down on me and I was able to shatter the remaining tap bits with a couple of chisels and punches, making the removal of the tailpipe possible.

 

I finished the drivers side hood side panel and rolled the car out into the sunshine for a couple of glamour shots. Now I'll need to do the hood. It seems like it should have a slight bulge in it. After I roll it and form it I am going to see if it will fit under my English wheel to roll in a little convexity.

 

A friend donated an unused socket (who needs a 31/32 socket?) to use for the hand brake bell crank. I'll weld it all together. The part of the crank that sticks up above the pivot will be left temporarily in case I need to affix a return spring or brake light switch up there.

 

Back on the hood -
I made a pattern of the "bulge" I desire. Then I decided to bend a piece of thinwall square tube to conform to the pattern. Since I had no large die for bending square tubing I used an old tractor gear for a die and formed a gentle arch in it. I will anchor the sheet metal to it. I may also do a piece of square on each side to give the hood some structure. The cowl is one inch higher than the nose so I do not want any more bulge than 1" max so the cowl doesn't go up hill.

 

More work on the center hood bow. I also made a tubular side piece which may or may not get incorporated into the hood, depending on how stiff the hood skin is by itself. I will make one for the carb side but it needs an arch in the middle of it to clear the carbs.

Finally I made a wood arbor to place the hand brake lever arm properly and work on the cables, without having to install the brake handle, which requires removal of the left hairpin control arm (aka ladder bar) which was becoming an annoyance.

 

After taking a few days to get ready for this year's drag racing season I made a couple of mounts for the rear crash bar attachment. The crash bars will be made from surplus stainless steel boat railing, purchased from a local boat salvage yard. In addition to the stainless railing I found some other useful boating items like bilge fans, the same fans used for brake cooling ducts in stock cars. I use them for transmission oil coolers and they are a fraction of the cost of new ones in racing catalogs.

 

Here is the 7/8" polished stainless steel boat railing I plan to use for crash bars. I have to knock off all the cast stanchions first. There already is some curvature in the tubes which should make fitting it up to the car easier, except I have no good way to put symmetric gentle bends in the tube. I may try to coax it in a #2 Diacro bender with homemade shoes and die.

 

Just watched this video last night:



In the comments, someone suggests using dry cement for an even better fill.

Jordan Bennett is the guy building the single seater race car here:

https://www.jalopyjournal.com/forum/threads/‘shoe-horn’-single-seater-speedster.1257714/

 

Thanks GHQCE. I remember as a tot watching my dad bend up a go-kart frame using sand filled tube and a torch. I am a little anxious about trying to do a sweeping gentler bend around the tailpiece. Ironically enough I have benders that will do a tight radius, its the sweeping arcs that are commonly done on a ring roller type of machine that I am struggling with. I may try doing gentle sweeps on a press but I'll still need to turn a 7/8" roller die or some such.

Boy, the more I work on this project the more I've come to appreciate the beautiful work done by the previous generation with less technology than available to us. GHQCE, You no doubt, have encountered this when working on early quick change axles, no?

 

Yes, some of the stuff guys have done to QCs is pretty creative. Some of it falls into another category.
Welding of Magnesium and Aluminum is all over the map. Some real artistry and some really ugly stuff. Brackets are the same way.

 

Last time I did some sand filled tube bending I dried the sand on a steel plate over a fire. It made pouring the sand in through a funnel a lot easier.

 

I affixed the crash bar sockets to the roll bar mounting plate. I leveled the sockets before welding. Then I inserted two chunks of boat railing to see how much additional bending is needed. Quite a bit to make them meet and follow the curvature of the tail.

 

Like some hot rod builds in general.

 

I saw this picture over on the "Vintage Shots From Days Gone By" thread and it made me think of your build and your hand brake/fuel pump/steering situation.

I've really enjoyed following your thread and seeing all of the creative ideas you come up with. Can't wait to see how the crash bars turn out!

 

Thank you stingbean. Its a tight fit in addition to getting things to look good.

Speaking of looking good, I am not happy with the look of my rear crash bars. I looked back at several pictures of cars and all of the crash bars are closer to the body than mine would be. So I have a new idea. I am going to make an offset plate to bring the crash bars closer to the body work. Stay tuned.

Speaking of looking good, take two: I want one of those ornate helmets like the driver of the Dayton Special is wearing.

 

A step forward and one back. I made stainless steel plates to offset the crash bars inward.

I also tried to make a vertical central nerf bar but when I tried to bend it it collapsed. I'll need to rethink how to do that. The sand filled trick may work but I worry that heating the stainless up cherry red will discolor it and change its properties.

 

Well, here's what I came up with for a crash bar. While I am not completely happy with the look it is the best I can do for now with my current technology. I may do something better in the future. One happy accident in all this is that I now have a convenient place to put plug-in tail/brake/turn lights.

 

Maybe some strategically places gusset plates may enhance the look or Maybe some faux aerodynamic cover plates at the attaching point to the body.
Just ideas out loud.

 

Maybe chessterd5.
It could have worked out better had I chosen to pinch in the rear of the frame rails. But I still have plans to attach a '27 T body in place of the champ body, thereby ending up with two cars - a roundy round champ car and a center-steered nostalgia altered with the same rolling chassis. I wanted the full frame width for mounting the '27T. We'll see.

 

MEMORIAL DAY
With the memory of all those hot rod hoodlum vets that never made it home -
that never had a chance to follow their hot rod hoodlum dreams -
that never had a chance to build their hot rod hoodlum cars -

I went to the shop to do some work. First I made a couple of brackets to hold up the front edge of the seat pan. But I ran out of argon so I tack welded them in with a MIG. I also put some arch in at the front to clear the tailshaft, and drilled holes for Clecos until I can install Dzus buttons.
Then since I had an empty argon tank to play with I jury rigged a crude radius brake to put the curvature in the hood top. The lovely Ms. Frenchtown Flyer was kind enough to help on the ratchet straps. We slid the hood in, pre-marked with tapered guidelines, and she clamped the blue strap tight, then I placed a piece of angle aluminum against the panel and pushed. We took it easy. Then she loosened the blue strap, lifted the landscape timber, re-positioned the hood and did it again. The first try did not give enough curvature, but we now have a system that will work and we can continue to add curvature until there is enough. Then a trip to the E-wheel to add some dome and done.

 

Well, now I know how I can make the hood for the Whatever project. Another idea to plaigerize...

 

Have at 'er Dave.
We continued to roll curvature into the panel until it had about the right amount. I need to order hood a strap kit. The edges will all need to be further defined. I'm thinking of rolling the front and rear edges under for a clean look. The sides may get reinforced with thinwall square tubing.
It still looks to have a concave surface. It is an optical illusion. That is why I have to do some E-wheel shaping to bring up the center of it.

Random recollection: I once bought an aftermarket pickup box for my '46 project. In the instructions for installation it said "When you install the box on the frame crossmembers the truck may look like it is sagging in the middle. That is an optical illusion. Correct it to suit by shimming up the front of the box to make it look level." I ended up shimming it up 1.5 inches to get rid of that sway-back look.







Tech tip for today: Positioning big panels into previously drilled Cleco holes is made easier by using these inexpensive stainless shish-ka-bob barbecue grilling skewers. Handy and cheap. 1/8" diameter

 

The side panels needed attachment tabs at a few corners. I had to weld on the upper tabs which, in retrospect, I could have just left enough metal on the panel blanks themselves to accomplish the same thing. No worries - I made them slightly thicker (.060") to withstand stresses. The top attachment points will all be hidden with the hood on so the Dzus buttons will not show.
I ordered the hood strap kit too.

 

I meant to post these pics with the last posting. Attachment tabs for the side panels.

Not much was done this weekend on the champ car as I spent it on a Bobcat doing some long neglected landscaping.

 

Fit up on the side panels. I installed Dzus springs on the attachment tabs. I put the springs in using aluminum rivets because I will remove them prior to painting so I can get good prep / coverage around the springs, after which I will permanently install them with stainless steel rivets. Now the hood top can be fitted up to the side panels.

Tech tip: I made a drill fixture tool to make Dzus spring installation easier and consistent.It fits the two most common spring spacings - 1 3/8" and 1".

 

Cutting the exhaust pipe on a bias looks great but one night at Middletown while were were putting on a show,I ran into the left tailpipe on my V-8 60 midget while in the pits. Cut me like a razor and still have the long scar on the inside of my right knee. After that I always put covers on the pipes to avoid more cuts. You are doing great work. Following your progress.

 

Thank you Donald for the tip. I will fashion some kind of plug for the exhaust. Until then, I've blunted / de-burred the edge.