Aluminum Mono

About a year ago I decided I wanted to build a TIG welded aluminum Mono chassis for my GT40. I know there is no good reason to build a new frame when the one you have is perfectly good but I like to learn new things and this seemed like a great way to learn. I have admired Frans design for years and have told him several times "man I wish I had thought of that!" After talking with Fran and explaining my reasons I started my design. After making all the sketches I needed I worked with Pete to create a solid model in CATIA to work out the details. I will attempt to share this chassis build with you as I have time and answer any questions. I have been working on this for about one year now so I'll attach pictures showing what has beeen done over that time.
A very sturdy frame jig was made using 6"X6" wide flange I beams. The sponsons were fabricated and welded. The floor pan was cut out along with the parts for the engine compartment. The sponsons were located to the floor and tacked in place. The transverse bulkhead was then welded in connecting the floor to the sponsons


For some reason I can only insert one picture? I'll try to post more. Here the sponsons are welded to the floor and the transverse bulkhead welded in.


Randy V

Staff member
Lifetime Supporter
Steve -
This is a very ambitious undertaking you have here..
A few things come to mind --
1) Dang that jig table looks nice, but it must weigh a ton
2) Dang that is a small workspace
3) Dang that's gonna be one huge electric bill :lipsrsealed:

About posting only one picture at a time -
I have the same problem if posting from my iPad or iPhone as this software on the forum sees all pictures as being labeled "image.jpg".. If you first upload to Photobucket or some other image hosting service, you can then upload multiple images from the host, or just use embedded links.

Nice work all in all and looking forward to seeing more!
Nicely done!

I look forward to seeing more.
Do you plan on using all the parts from your other car or are you just making a new car?

Thanks for the posting advice Randy, now I can upload some more pictures!

Howard, I am going to use most of the parts from my car but all the suspension and steering will be redone.

Wanted to repost the first picture right side up!



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Fran Hall RCR

GT40s Sponsor
Ha...about time you broke cover Steve...

damn that looks familiar..:lipsrsealed:

Its quite a compliment from a Boeing engineer

Happy Thanksgiving mate..
Thought it might be time to share! Like I said Fran, Man I wish I had thought of that! YOU ROCK DUDE... I can say that you become adept at welding in all kinds of wierd positions. I will be better when I'm done than when I started for sure.

Hope you and your family have a very happy thanksgiving Fran!
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Hi Steve,

looking great. :thumbsup:

Good to see another one stepping into the ring to tackle building an ally mono tub.

Are your panels laser cut?


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rockonsmileThanks Marcus! All the panels have been cut with a skill saw with a carbide blade except the larger ones that were sheared. The bending was done at a shop close by with a 12' press. Love your build by the way, what a work of art.

Very well done Steve, how's your back from out of position welding? Mine hurts just looking at the photos!
Here is the chassis! The seats will be welded into the chassis for added strength like the original.


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