Another build thread? Yep, my track-style T

[J. Robinson]

Thanks to all you guys. I'm glad you're enjoying this thread so far.

Don: No need to bow; I don't think I'll be casting any blocks. I have been known to weld broken leaf springs back together, though. Amazingly, it worked!

Bobby D: Don't worry, there won't be any appreciable flex in the frame. Notice all the triangulated bridgework between the upper and lower rails? When finished, this frame will be stiffer than the average 2 x 3 rectangular tube frame. I know of a sprint car that was built from black iron pipe in the mid 60's. It was still in competition in the early 80's when I lost track of it. In over 15 years of competition it had never cracked anywhere.

Dreamin' Mike: I haven't decided on the engine yet. I am seriously considering using some kind of 4-cyl. The majority of early track roadsters used four-bangers. The Ford flathead didn't take over until near the end of the roadster era when many of them were transitioning into sprint cars. Of course, the flathead was eventually supplanted by the small block Chevy. Anyway, I dimensioned the frame so there would be room to put a small-block in it (I have two more 350's and a 327 in the shed) just in case I decide to go that way. Whichever I finally decide, I want a four or five speed tranny.

[bluestang67]

Jim seen all the webbing , i know it gives strength . What size is the pipe for future reference. Any hoot would have liked the bender to do A bracing in round but i dont do enough of this yet to offset purchase. I eyeball the ones at work when there bending 4 inch conduit .

[J. Robinson]

Good question, Bobby. I guess I did jump ahead a little. The main frame rails are made from 1 5/8" OD tubing (1 1/4" black iron pipe) and the secondary tubes (bottom rails) are made from 1" OD (3/4" pipe). The little uprights and the diagonal bridgework pieces are made from 3/4" OD (1/2" pipe). The combination of different size tubes gives it a nice look.

If anyone is considering doing some of these things, let me give you some common sense warnings. First, never use ordinary galvanized water pipe for any structural member or for any steering or suspension component. The zinc coating on galvanized pipe contaminates and crystalizes the welds gauranteeing that they will fail eventually. Second, the fumes emanated from welding galvanized material can be deadly!

Black iron pipe is just mild carbon steel tubing. The coating on it is a shellac-based paint that burns away completely at the weld, so it does not contaminate the molten weld puddle. Later on, the remaining coating can be removed with lacquer thinner or by sanding it off. I have many times just given it a light sanding and primered right over it. I am yet to have it lift or create any kind of painting problem.

I bought my tube notcher ($29.99) and pipe bender ($69.99) at Harbor Freight specifically for this project because of all the round tubing I am using. In the past, when I have only had occasional need to notch a piece of tubing, I did it with a hack saw or the chop saw and finished up with a grinder.

Let me say here, for the beginners out there, that exotic tools are not required for building hotrods. I built the car below with very basic tools. I used a carpenter's skill saw with an abrasive blade to cut the frame tubing and either a torch or a hacksaw to cut everything else. I dressed cut edges with the bench grinder or a disc on an electric drill. All welding was done with my old Linde stick welder. In the 32 years since I built that car I have accumulated a lot of tools that make the job easier and faster, but my point is, you can make do with very basic stuff if you are determined enough.

[J. Robinson]

Continuing with the radius rods, obviously there has to be something to hold the rod ends in the open ends of the tubes. I am using 1/2" rod ends that I bought from Speedway Motors. Nobody that I have found makes a thread insert or "threaded bung" that fits my application, so I have to make them myself... I buy these things called "coupling nuts" at the local ACE Hardware. Their real purpose is to join the ends of threaded rod for long applications and they are available in many thread sizes. I then turn them in a lathe at school so that they will just slide into the tubing I am using. I leave about 3/8" of one end uncut so that there is a shoulder to keep ithem from sliding too far into the tubing and to provide a weld area. If you don't have access to a lathe, this step can be accomplished with a grinder. Thread the coupling nut onto an old bolt and grind carefully. It's slow and tedious, but I have done it successfully.

Next, I cross drill the ends of the tubing so that I can plug-weld through the holes into the sides of the "bung". One additional step I did on this set of rods was to drive a 3/8" nut in the opposite end of the short pieces, tack welded them in place, and ground the welds flat. After the rods are all finished and painted, I will add a little chrome bullet here for a nice detail.

Then, I weld the bungs in place. I plug-weld them through the holes first and then weld all the way around the ends. I let everything air-cool so the steel doesn't get tempered or work-hardened and then grind the welds smooth using a hard wheel first followed by a sanding disc.

Finally, I run a tap through the bungs to clean up any deformed (from the heat) threads and remove any welding slag. The individual pieces are ready to weld together into a finished radius rod now.

[Uptown83]

looking great!

[brianrupnow]

JRobinson---I don't think that you were a member on this forum when I did the build series on my roadster pickup about 3 years ago. I know that Don was. Best luck to you---I will be following your thread and enjoying it. thank you for posting, and if I can help with any questions, I will. --Brian

[firebird77clone]

black pipe, way cool. I was pondering the same type frame build using 2-1/4" exhaust tubing. Probably too thin? What about sch 80 pipe?

[J. Robinson]

Thanks, Uptown.

Brian: I just got in at the very end of your build. I have seen and enjoyed several of your tech articles, though, especially the duvall style windshield.

EG: Regular black iron pipe has pretty substantial wall thickness already. Schedule 80 is almost twice as thick and therefore weighs almost twice as much. Also, it's just about impossible to bend it, so you are limited to straight line designs. You can use it (as long as it's black and not galvanized), but it would be a case of "extreme overkill". Exhaust pipe (we used to call it "muffler moly") is thin and soft, definitely not good for stressed structural members. Many a roll bar was built of the stuff years ago and it was sheer luck more people weren't killed.

[Dave Severson]

Thanks to all you guys. I'm glad you're enjoying this thread so far.

Don: No need to bow; I don't think I'll be casting any blocks. I have been known to weld broken leaf springs back together, though. Amazingly, it worked!

Bobby D: Don't worry, there won't be any appreciable flex in the frame. Notice all the triangulated bridgework between the upper and lower rails? When finished, this frame will be stiffer than the average 2 x 3 rectangular tube frame. I know of a sprint car that was built from black iron pipe in the mid 60's. It was still in competition in the early 80's when I lost track of it. In over 15 years of competition it had never cracked anywhere.

Dreamin' Mike: I haven't decided on the engine yet. I am seriously considering using some kind of 4-cyl. The majority of early track roadsters used four-bangers. The Ford flathead didn't take over until near the end of the roadster era when many of them were transitioning into sprint cars. Of course, the flathead was eventually supplanted by the small block Chevy. Anyway, I dimensioned the frame so there would be room to put a small-block in it (I have two more 350's and a 327 in the shed) just in case I decide to go that way. Whichever I finally decide, I want a four or five speed tranny.

The four banger gets my vote!!! Don't know if you have any contacts in the midget racer ranks, but I would think there are some awesome Pontiac "Iron Duke" 4 banger parts laying around someplace.... They were a great engine in the midgets, tons of torque. Got to drive one over at one of the Wisconsin tracks one summer in the early 70's... If you could locate some of the go fast goodies that some of these guys have stashed, would be great.... Or, if you're really feeling lucky, and have a big checkbook,,,,,,,an Offy would be the ultimate engine for the car!!!!!

As for the tubing, properly braced and gussetted it should be ok. I get a little nuts on materials sometimes, guess my choice would be the exact opposite end of the spectrum and be chrome moly. But, done properly, and so far your's looks fine, black pipe will work. I would reconsider the hairpins, and maybe spend a few extra $$$$ for some DOM for the suspension pieces....Again, with the right amount of gusseting the black pipe will work... Much as I hate to admit it, the first modified I raced had frame rails and roll cage made of black pipe.... We unknowingly bought the car that way and discovered it after a big tumble...The car was junk but the cage (and me) survived because it was super braced and gusseted.....

[Itoldyouso]

Coming along really well. I also like the C cab you had. I didn't know you had built one of those too.

Enjoying your thread a lot.


Don

[hotroddaddy]

Man you and don are really making me want to build a car from scratch, i dont want a roadster, so maybe i will build a c-cab soon

[bluestang67]

Hotrod there making me want to visit ebay and do a looky look myself. Wife dont like it when i fill the drive and garage though.

Jim your work is great and tech articles help people like me doing something simular.

[brickman]

Nicely done J. Robinson, I like everything you are doing and we all love these builder threads, looking forward to a great ride along with yours. I am very interested in where you got the plans for the tube frame? Did you design it yourself?

[firebird77clone]

K, you sold me on the black pipe. Sounds good. Still thinking of exhaust tubing for the 'cage' though.

One note on galvanized: If you grind off the zinc before you weld, you'll be ok.

[J. Robinson]

Thanks, everybody, for the compliments.

Dave: I am leaning heavily toward the 4-banger myself. I think this car would be really cool with a "Belanger style" 3 inch exhaust pipe running back along one side and exiting above the rear tire like an old midget or Watson Indy roadster from the 50's - 60's. I don't know anybody from the "midget wars", but that's a great suggestion. I have a line on a 2.5L 4-cyl & 5-speed in a wrecked S-10 pickup that I might be able to get cheap. I know (from my days as a Fiero owner) that the 2.5 has a weak bottom end, but it would help me to get this car together quickly and an "Iron Duke" would be a bolt-in swap later if I could get one. Another possibility is an Oldsmobile Quad-4. With the center cam valley cover removed (it's just a cosmetic piece), the Quad-4 looks a lot like an Offy. The problem with a Quad-4 is that it has no distributor and no place to put one! Maybe there's a crank-trigger assembly or something that fits it; that would take some research on my part. A real Offy would be a dream, but a school teacher's checkbook stays pretty thin...

You probably already know this, Dave, but, for the benefit of some who may be reading this, let me talk about the differences in mild steel and chrome moly. Metalurgically speaking, chrome moly tubing may actually be a poor choice for a street driven vehicle. It woul be fine for a roll bar or cage, but probably not a good choice for the frame. Also, it can be a disaster for the home builder / hobbyist such as myself to work with. Let me explain (Sorry guys, it's the teacher in me coming out)...

The advantage to chrome moly is that it has a very high "elastic limit" (the point at which a piece of metal being flexed stays bent) and immense tesile strength. Therefore, you can achieve equal or better results (compared to mild steel) with less mass. I believe I read in the ECTA rule book that roll cages may be made of minimum .125" wall mild steel or DOM tubing or .083" wall chrome moly. The inference here is that chrome moly achieves equal or better strength with about 30% less mass. In racing, where every ounce counts, 30% reduction in weight of a component is a big deal.

Aside from the expense, the problems with chrome moly begin with welding it. Properly done, it must be TIG welded. Sometimes it can be MIG welded, but it's risky. It absolutely should never be stick welded. When welding chrome moly with a stick welder (or improperly set up MIG), tiny microscopic cracks form like spider webs in the metal on both sides of the weld. Eventually, after being repeatedly stressed, the weld will pull out of the base metal. TIG welding concentrates the heat in a much smaller area and thereby eliminates the cracking problem.

Another problem is repairing damage. If mild steel gets bent or kinked, it can be carefully heated and straightened. If it cracks, it can be welded up and ground smooth. If chrome moly gets bent or kinked it should be replaced. If you overheat it while trying to straighten it, it loses its elastic properties and basically becomes the same as mild steel. If it cracks, it must be TIG welded. If you grind the weld, it work-hardens the surrounding area and makes it brittle. OK; that's enough for today's lesson in Metalurgy.

If you can get mild steel or DOM tubing, it is a better choice than black iron because it has a smooth outer surface, the wall thickness is more uniform, and it will actually be lighter in weight. In this one-horse town, to get good tubing I have to drive 50 miles to the other side of Orlando, order it, then make a second trip to pick it up...

Thanks, Don. That C-Cab was my first hotrod (actually, I started a different hotrod several years earlier, but sold it before it was finished). I began construction of that car in October of 1975 and drove it to its first rod run in September of 1976. (For some reason it takes me longer to build a car now...) In 1977 I drove it to St.Paul, MN for the NSRA nationals and it ened up on the cover of Street Scene, November '77. I sold it in 1984 and it now resides in Huntsville, Alabama. It is Black with flames now. (If anybody out there is from the Huntsville area and you see the car, please tell the owner to contact me. We have conversed a few times, but lost contact.) That was one of 7 cars built from my original plans. The frame was similar to a T-bucket; I built the body from 3/8" plywood and fiberglassed it all over. That pic was taken in 1979. At the time, I had a grand total of $1700 invested in that car! I can't seem to build 'em that cheap any more.

Hotroddaddy, I still have my original plans...

I have attached a pic of my original C-Cab as it looks now in case anybody sees it. The second pic is of the second one I built for myself (the last of 7 built). I sold it to a guy in Miami, Florida. As far as I know, it's still there...