1930s Era Champ Car - new project

The new welder is very nice. I have used it on this project to mostly fill some pin holes left from my first attempts to join panels together. I am looking forward to doing all the chassis parts - mostly fabbed from 1/8" steel - as work continues.

 

Keep up the good work

 

After struggling with this tail section for several months I made some real progress over the last week. I married the tail to the hold down flanges. I ended up cheating a little by making three pie cuts to get the sides to lay flush inside the flanges. I'll weld the pie cuts next. Before I plug welded the two together I put rustproofing on both the inside of the flanges and the outside of the tail where they join to prevent rust from developing inside the sandwich. I cleaned off the rustproofing locally before I welded each plug weld.
For now I will continue to use Clecos to hold it on to keep the alignment precise. I still want to do a little more smoothing on the skin. Later it will be converted to period correct pan head slotted screws.
Next comes affixing the seat back panel to the tail section. Additional structure will be placed behind the seat to hold the anchoring system for the 5-point harness.

 

To mount the seat back / tail access panel I got some help from my friend Fast Freddie from Canton Ohio who himself is a legend in Legends / Dwarf racing. He provided me with a nifty magnetic zero-centered tape that is very useful for laying out symmetric curves. I used it to bend up this mounting flange which will get welded to the front cover. Here I plan to fasten it with Dzus fasteners, but they will be hidden under the upholstery. I'm thinking nine or 11 fasteners will be needed. The restraint anchoring system will be housed out of sight behind this panel.

 

I clamped the seat back to a board using several pony clamps to noodge it into place. Before welding in the flange I formed the mounting holes for Dzus fasteners which will be hidden by the overlapping flap of the upholstery. I made a few spacer tabs to maintain the root opening, then tacked the mounting flange into place. I plan to go back and TIG the two pieces together, but the temperature was 100*F in the shop, so that is enough for today.

 

Before I affix the seat back to the tail section I want to put in an opening for the shoulder harness. But in order to prevent abrasion of the belts on the tin I will put a rolled radius in the opening. I made up a wire form to wrap the tin around.

 

ring installed



In retrospect it would have been a lot easier to install this ring before installing the sides as I could have rolled the lip with a bead roller instead of having to hammer it in.

 

With the help of my spouse I crawled up inside of the tail section (many times!) to align the seat back to the tail and while she held everything in place. I drilled out temporary holes from the inside and she inserted bolts to hold everything aligned from the outside. I saw slit a 1 x 2 to slip over the bottom edge so I could jack the panel snugly against the tail. Eventually the bolts are to be replaced with Dzus fasteners which in turn will be concealed under the upholstery flap. So far, so good. The two lower holes are yet to be drilled. I marked the inside edge so I know where to mount the restraint anchor tubing. But first I'll mount the gas tank to see how much room there is left for the restraint hoop.

 

As long as I'm working near the tail I think I'll do something about the temporary exhaust pipe support. I fabbed one up of steel tubing, turned a bung, and rolled a saddle to hold the 4" pipe. I made a little "paisley" anchor plate of 3/16" to steady it.

 

The valve cover for the crossflow head had an oil fill cap on a tall standpipe at the front of the cover. It was going to interfere with hood clearance. I removed it and relocated amidships at the lowest point of the cover. Now I will have enough room to mount the DOHC cover.



Progress for the last few days:

 

Continuing with the harness mount. I had to lengthen the legs; I used 1" x .095" seamless and bored it out so the 7/8" reinforcing sleeves would fit snuggly inside. That is probably all I may get done this week as I have to prepare for the upcoming Detroit Dragway Reunion this weekend.

https://www.jalopyjournal.com/forum/threads/detroit-dragway-reunion-saturday-july-25.1200342/

 

I had a couple of hours last Friday before we went racing for the weekend so I decided to do a couple of fab jobs. I was going to weld the conical gussets to the bottom of the roll bar mounting sockets. I had one in my hand before I went inside to take a phone call. Do you think I could find it after the call? Nooo...
I looked for it for the better part of two hours until it was time to go.
This morning I decided screw it, and I just made a new one (1 hr, 20 minutes). These gussets will distribute the roll bar loading along the entire width of the frame rail. I've seen some pretty sketchy roll bar mounts. The roundy round techies must not be nearly as picky as the NHRA drag techies where mounting points, tube size, welding technique, etc. is precisely regulated. Any way, it should hold securely. Then I made brackets for the inside harness hoop. The triangular top to these tabs is not purely for aesthetics but it will distribute the forces gradually along the hoop, reducing the chance of breakage.



[PS: Qualified the Last Logghe Altered #1 on Saturday. Lost in the finals.
Sunday lost first round in my avatar S/P car. Bought back in for the second round. Lost again. Hero-to-Zero in nuttin' flat.]

 

Hey making it to the finals is nothing to sneeze it.

 

Thank you. There's lots of good pics over on

https://www.jalopyjournal.com/forum/threads/detroit-dragway-reunion-pics-added.1200342/

 

I installed the main 5-point restraint hoop and the roll bar main hoop.


When I weld in receptacles to hold roll bars I have found it useful to wrap tape around the roll bar so that it is a very snug fit inside the mounting receptacles. That way if the receptacle cup wants to shift or distort during welding the tape acts to hold the pipe firmly centered in the middle of it so dis-assembly and re-installation is easier once I remove the tape.

 

What's the "extended" front bumper/? for. More rollout?

 

Not exactly.
NHRA mandates that no part of the car may extend more than 30" in front of the spindle and it must be rigidly mounted and at least 3" above the pavement. But they do not dictate the front spring rate.
Ergo, if I were to strictly conform to the NHRA rules but design my own torsion front spring system that allows the air pressure to deflect the car below 3" going through the lights it is just possible the wing (ahem..."front bumper") will be deflected downward enough to trip the finish line beams, effectively shortening my side of the track by a couple of feet.

Many Pro Stock teams discovered this before me. I used it on my Logghe car too

I built that racer in my garage - chassis and body - so I was able to tailor each piece. For example, I used 2.47:1 rear end gears to insure that car would hook in a mudslide - never spin the tires. I put a manually operated stop light switch button on the top of the hand brake so I can hit the stop lights without hitting the brake; hit the brakes without hitting the stop light; or hit both the brakes and the stoplight switch. I did some stuff perfectly legal but I had not seen on any other car. Some stuff I'm not ready to reveal. I also put all necessary street equipment - turn signals, horn, etc - if I had a windshield with rear view mirror I could have driven it to the track.

 

Back to the champ car.
I welded on the mounting tabs to the harness restraint bar including the belt locator at the top of the hoop, with a pin to secure their location.

 

Can somebody tell me if vintage racing organizations stipulate the location of the diagonal triangulating struts for the roll bar and restraint hoop(s)? Specifically, how high up on the main hoop they are to be placed? Also, tube diameter and fastening tabs? I was planning on using a clevis in double shear for the restraint hoop in 7/8" diameter. Main hoop TBD...

 

OOPS!
I goofed.
I made a mistake.
The roll bar interferes with the exhaust pipe. By about an inch.

So I made up an offset saddle mount, cut and welded it back together so the roll bar and exhaust pipe can coexist.

I see the number of views for this build has surpassed 100,000. Thanks to all who have continued to follow this build all these years. Your support helps motivate me. Hang with me - we'll see it run.

 

This build rules. Keep it up

 

Diag braces for the restraint bar...

 

I made a detour today. I mounted some deep dish Moon discs to the '46 push truck. I drilled and tapped the rim and installed stainless 10-32 studs so I can hold the discs on with stainless acorn nuts. That way I can remove them easily if need be, like for adding air.

 

Good move, looks perfect now.

 

The harness restraint mounting bar struts are spotted in. I spaced them outward in hopes the 8-gallon fuel cell I have will fit but I have my doubts; its hard to say without the bustle in place. Maybe turned sideways, but the fuel pickup location would be a bit wonky. I better look for a smaller (5-gal?) tank. Next I need roll bar diag struts. I can't decide how they should be mounted to the frame so the bar can be removed.

 

Awesome work, you got skills!

 

Thank you FinnishFireball.
Little progress today - I had to go into town for more argon shielding gas.
I did study some old cars and chose a mounting technique for the roll bar diags and made up the patterns in wood. Tomorrow I make them in steel.

 

Roll bar diag mounts:


I copied a design I liked from older cars. It looks safe to me (I saw some attachments that sure didn't).
I like curved surfaces. It looks artsy to me; almost evokes an aeronautical vibe to things. I made these brackets with curved edges. It would have been easier to chop them off a piece of flat bar stock.



There are two weld nuts inside the rear of the frame for mounting these. And the rear crash bars.



The diags get fish-mouthed and welded securely on both ends. This time I'll check to be sure they clear the exhaust pipe.


I think a couple of round wooden discs turned down to fit inside the skived tube ends will precisely align them to the mounting plates.

 

Flyer , you’ve been busy, every thing looks great .

 

Thank you JOYFLEA.

I installed the roll bar re-enforcing diagonals. I finish welded the harness hoop.

Once the roll bar gets finish welded the rear of the chassis'structure is effectively complete. I can begin to move forward into the driver seating area to lay all that out as ergonomically as possible.


One near OOPS was the fact that the roll bar attachment points just barely clear my trailer ramps when the ramps are in the stowed upright position. I will have to reposition the ramp locking arms so they don't interfere, but that is a minor rework.
The blue spacers sandwiched between the frame rail and roll bar are there to simulate the mounting pads for the rear crash bars which will attach through the same holes and will be fabbed up later.