Dragster frames........picture thread.

Another GREAT thread !!!

 

Royal, Thanks for startin' another cool thread.
I'm still lookin' for Dragmaster Dart trailer info.
Have a good one,Smokey

 

These frames are not totally retro but about as close as you can get and pass the current certs. As shown they will cert to 6.0 and with the addition of diagonals in the rear axle bay they are good for as fast as you can go. Moving the bottom of the front cage hoop forward as per Conder's Pete Ogden built cars would make them look a little more old school too.

Roo

This is a 200" wheelbase frame that we did a couple of years ago. The six point flat top cage is the only thing that spoils it appearance wise. The frame on the jig in the background is a shorty 185" unit.

The car in the foreground is one of mine (Mark Vaught) and the other is Mike and Troy Coker's Boulton chassis. The red car in the background is my 1970 Don Long

The kidney bars below the shoulder hoop assure that it will pass tech and in this car provide a mounting point for the wheelie bars as well.
Too much electronic crap but at least the basic frame looks suitably retro and will certify. I have an Autocad drawing of this car if anyone is interested or we can build anything from a welded frame to a complete roller.



Wishbone front ends may be lighter but we like the retro look of an axle.

 

rooman,
Please post the AutoCAD file of the rail frame. Some of us here are VERY interested and can actually open it and read it.

Please, please, please, please!!!

 

i use acad 14

 

Thanks guys!!You just made my Christmas!

 

Was gas welding the norm back then for roll bars and frames?I know there werent any mig or tig welders, was arc welding used?

 

Excellent thread.

 

Neat thread.

 

chrome-moly was designed to be gas welded is my understanding, used in air frames. i have to take a pic of my frame today and post it, i'm hoping that in canada i wont have to worry so much about certs. and will be able to run it without totaly bebuilding it.

 

Actually tig welding (heliarc) has been around atleast since the late 50`s I still weld my chasis together with a 1962 model heliarc welder, at Garlits shop.

 

Pete Ogden's last one...

 

Dragmaster style car Im currently building.

 

Now that's cool! How did you bend the big radius for the back hoops?

 

TIG was around (actually called HeliArc at the time 'cause they used Helium as the shielding gas), but 4130 tubing was developed for use in aircraft frames and was meant to be gas welded (when it was developed, there was no such thing as TIG).

A TIG torch makes for a better looking weld, but it is my understanding that a TIG welded 4130 chassis must be annealed before it can be used due to the possibility of stress cracks developing in the HAZ.

I remember reading a story about the first TIG welded roadster chassis to be run at Indy. They were so afraid of cracking that the tech officials required a weld inspection at the start of every day it was going on the track. IIRC it was Smokey Yunick that built it, and it was carrying his first major foray into reverse rotation motors for oval racing (an Offy I do believe).

 

Am I the only one with wood right now?

 

NO

 

BAD ASS POST!!!!!!1 Hopefully one day I will have one of these. Hey I got an idea, anyone want to trade a rolling chassis for a 40 merc? see my ad in the cars for sale.

 

This has to be the coolest photo I've seen in a long while. thanks for posting it on this great thread. Is this dragster the one I've seen at Flathead Jack's?

 

You sure? I've been FOS before, but I'm pretty sure I read that in a text book I have around here somewhere.

Now I'm going to have to go dig it out.

But barring my finding the text in question, I will stand corrected.

EDIT:

Alright, I found it, in an old Miller welding pamphlet. It suggests all thin wall aircraft type structures be oven normalized to remove martensite inclusions that may be present from the thin section air cooling too quickly after the TIG process. These inclusions can lead to stress fracture in the HAZ. This is a very real problem that has been know about from the very early days of the TIG process when applied to aerospace tube frames (and their correspondingly thin walled tubing).

However, that said, I also did some more digging and found a post on Miller Welding's motor sports forums from the guy who fabricates John Force's funny car chassis (among others). Goes by the nick of "fuelcarbuilder". Anyway, his contention is that the NHRA rules dictate such thick sections (and thusly large amounts of heat to make the joints, along with the correspondingly longer cool down time) that martensite inclusions are not a problem, therefore no post weld normalizing is required. He also stated that NHRA does not require said normalizing, so I'd guess it's not a problem when dealing with drag car chassis.

So, it appears that you were right, in this context, no normalizing is required for TIG welded 4130 cages, at least in NHRA's eyes. I dunno for sure, I don't work with the stuff, I just remembered reading that text book and then later reading the same thing about that Indy car.

EDIT #2:

Ran across an interesting article that is pertinent to drag car chassis design and construction, having to deal with heat treated 4130 tubing being used in fuel and FC chassis. It's a pretty good read, dunno if it's entirely right or not, but a good read none the less:

http://competitionplus.com/index.php?option=com_content&task=view&id=4358&Itemid=24

EDIT #3:

The more I look, the less FOS I feel. This article is about the McKinney shop that the above mentioned fellow works for: http://www.millerwelds.com/education/articles/story142.html

Their best practices outlined the article are exactly ass backwards of what anyone who's fabricated with 4130 in aerospace knows to be common practice (for very good reason).

The more I read, the more I think that drag car chassis builders are taking the "head in the sand" approach to 4130 welding. TIG is how they want to do it, and there's not been a major crap-up so far, ergo it must be safe to do it that way.

Either way, I think I'll stick with mild steel for my cages thanks.

 

Found in a wrecking yard.

 

FYI-http://www.lincolnelectric.com/knowledge/articles/content/chrome-moly.asp

 

Read it. FAQ's are vague on purpose.

At any rate, I've derailed the train enough for one day, I'll refrain from making any more OT posts.

Please let the pictures continue.

 

Better pics of the one I showed on post #17

 

Same car with body on