Page 1 of 23 12311 ... LastLast
Results 1 to 10 of 229

Thread: 1962 Ferrari 250 GTO scratch build

Hybrid View

  1. #1
    Senior Member C5GTO's Avatar
    Join Date
    May 2015
    Location
    Livermore, CA USA
    Posts
    218

    1962 Ferrari 250 GTO scratch build

    This is a build story about a car I refer to as a “C5 GTO”. It’s a hand built replica (sort of) of a 1962 Ferrari 250 GTO. If you’re not familiar with the GTO, here’s a picture of some at Pebble Beach.



    The GTO below (#3943GT), I was able to get access to for pictures, templates and taking measurements. That's me taking tail light measurements. While GTO’s are rare (only 39 ever built) and quite expensive (one sold for $38.5 million last year), this GTO is still used actively in vintage car races and the rear axle was out for repairs when this picture was taken.



    What’s the C5 part you ask? I’ve made extensive use of 5th generation, C5 Corvette parts in building this car. I sourced the engine, trans-axle, suspension, steering, and brakes from Corvettes of model year 1998 through 2004.

    The reason I say it’s sort of a replica is that in addition to the C5 internal parts, I also had to re-style the body shape to account for a difference in track width of 6 inches. I wanted to use the complete unitized front and rear Corvette suspensions so the track width couldn’t be narrowed. The wheel base is same as original but the C5 GTO is wider. I personally think the ’62 GTO is one of the best styled car bodies ever made, so my basic challenge was to not “screw it up” while making the body 6 inches wider. The most succinct description I’ve heard on the visual difference is that the C5 GTO looks like a real GTO that’s on steroids. Sort of like comparing a 289 FIA Cobra to the 427 SC model.

    I’ve been working on this project for about 14 years now. Why so long, simple answer is, "life happens" and I do have other priorities like family and work. If this is the first time you’ve heard of the C5 GTO, I’m starting the story in this thread not from the beginning but somewhere way down the line. You might have read about the C5 GTO in either Kit Car Illustrated or Kit Car magazines before they went out of circulation several years ago. Word got out to a magazine editor when I decided to do the project and they convinced me to write a recurring build article which I called, “Last Chance Garage”. I’m not a car building professional or professional writer but just a car guy who likes cars not made in a factory.

    The first thing I did when starting the project was to make a plan for the chassis. Nothing fancy but good enough so I could get it reviewed by a chassis builder. His opinion was that I’d over engineered it and he helped identify where I could simplify it. Once you see the actual chassis, you’ll probably chuckle because it still looks like a pile of pick-up-sticks. Here's the chassis plan top view.



    Given where I’m at on the project now, most of the early parts I’ll show mostly in pictures. If you have questions or want more context, please post/ask them. I’ll try to answer the best I can.
    Joel Heinke
    Be original; don't be afraid of being bold!

  2. #2
    Senior Member C5GTO's Avatar
    Join Date
    May 2015
    Location
    Livermore, CA USA
    Posts
    218

    C5 GTO chassis build

    Here’s some pictures of the space frame chassis. I started by mounting the suspension to a I beam frame and aligning the wheels. I then built the chassis to connect the front and rear suspensions. I had to have the torque tube and drive shaft shortened because of engine set back and a shorter wheel base than the C5 has.











    I designed and built this chassis specifically for this project. It’s the first chassis I’ve designed or built so the jury’s still out on whether it’s a good design or just a mediocre one. I followed the chassis design principles of Herb Adams in his book Chassis Engineering. The main strength and rigidity in this chassis comes from the oversized transmission tunnel/backbone that’s fully triangulated on all four sides. I’ve found that I can’t jack the chassis and raise one tire at a time, two tires always come up. I do get cracks from people that my design looks like the Masserati “birdcage” chassis.



    Front and rear suspension is from a ’98 Corvette. I designed the chassis to use the cast aluminum suspension cradles which use 4 bolts each to attach them to the chassis. Power is driven through a 6 speed transaxle which places a good bit of drive train weight back on the rear wheels. The engine is setback 12 inches from normal Corvette placement resulting in a 55% rear to 45% front static weight ratio. Normally a front engine car is heavier in front than rear but this one isn’t. My goal is to get enough rear tire traction to minimize wheel spin but also get great corner handling as well. A 25 gallon fuel cell is squeezed in at the rear of the car to safety store the fuel.

    Last edited by C5GTO; 05-20-2015 at 11:19 PM. Reason: fixing pic URLs
    Joel Heinke
    Be original; don't be afraid of being bold!

  3. #3
    Junior Member
    Join Date
    Jun 2018
    Posts
    5
    Hi Joel, Just started reading from the beginning, and my first question is how did you shorten the Torque Tube and keep both ends parallel ?? and also the actual Prop Shaft ??? any help appreciated as I will be doing the same on a Maserati 4200 Torque Tube and shaft, Thanks, Regards DM

  4. #4
    Senior Member C5GTO's Avatar
    Join Date
    May 2015
    Location
    Livermore, CA USA
    Posts
    218

    Arrow

    Quote Originally Posted by Dinoman View Post
    Hi Joel, Just started reading from the beginning, and my first question is how did you shorten the Torque Tube and keep both ends parallel ?? and also the actual Prop Shaft ??? any help appreciated as I will be doing the same on a Maserati 4200 Torque Tube and shaft, Thanks, Regards DM
    Dinoman: The short answer is that I had a driveshaft shop that had the necessary equipment and skills do it. I believe it was cut and welded on a lathe or maybe a special welding fixture used for fabricating long cylindrical objects. I seem to recall shortening the aluminum drive shaft was much easier for them than the torque tube. The reason being this torque tube is made from an aluminum/ceramic composite/matrix material and the driveshaft is just aluminum. I remember them saying that cutting this torque tube was not easy at all. In addition, I had to find a welding expert that could provide them with the information on proper filler wire, heat/amperage, and speed to weld it since they had not welded on this material before. Aluminum matrix driveshafts are a lot more common now so there's probably more places that have experience with them these days.

    I could give you the name of the shop that did the work but I know the guy who did the work has since passed away. I'm guessing that shop may not have done another one since. My advice is to figure out if you're dealing with an aluminum alloy or an aluminum composite material. If just aluminum, then it should be easier for you to get it shortened.

    Good luck,
    Joel Heinke
    Be original; don't be afraid of being bold!

  5. #5
    Junior Member
    Join Date
    Jun 2018
    Posts
    5
    Quote Originally Posted by C5GTO View Post
    Dinoman: The short answer is that I had a driveshaft shop that had the necessary equipment and skills do it. I believe it was cut and welded on a lathe or maybe a special welding fixture used for fabricating long cylindrical objects. I seem to recall shortening the aluminum drive shaft was much easier for them than the torque tube. The reason being this torque tube is made from an aluminum/ceramic composite/matrix material and the driveshaft is just aluminum. I remember them saying that cutting this torque tube was not easy at all. In addition, I had to find a welding expert that could provide them with the information on proper filler wire, heat/amperage, and speed to weld it since they had not welded on this material before. Aluminum matrix driveshafts are a lot more common now so there's probably more places that have experience with them these days.

    I could give you the name of the shop that did the work but I know the guy who did the work has since passed away. I'm guessing that shop may not have done another one since. My advice is to figure out if you're dealing with an aluminum alloy or an aluminum composite material. If just aluminum, then it should be easier for you to get it shortened.

    Good luck,

    Hi Joel, Thanks, My torquetube is steel with forged and welded on ends, and actual Prop Shaft is a narrow solid steel bar with splines on each end. my other question is have you any info on the GTO handbrake lever, looking and lots of pics online it looks like the main handle is in two pieces one the rear one could be main tube and the one at the front the actual rod to move the pawl on the ratchet, if you have any pics or advice it will be much appreciated, cant wait to see yours back from the paintshop, I have just read your piece on making the headlight cover alu rings very nice as I was wondering how I was going to make mine so again thanks for all your info, Regards DM PS I am in the uk.
    Last edited by Dinoman; 06-08-2018 at 10:36 AM.

  6. #6
    Senior Member C5GTO's Avatar
    Join Date
    May 2015
    Location
    Livermore, CA USA
    Posts
    218

    C5 GTO chassis build (cont.)

    The chassis has a built in roll cage meeting SCCA specification. It’s constructed of carbon steel DOM tubing the main structural and largest tubing members being 1.5” diameter. There’s a mix of 1” and .75” tubing used for triangulation. All the tubing “fish mouths” were cut on a Joint Jigger with hole saws in my drill press. All the welding was completed with a TIG welder. I was a newbie at TIG welding when I started the project and needless to say, I’m quite proficient now.

    Here’s the bare chassis after it returned from being powder coated:





    I fabricated the chassis, assembled all the drive train, installed the fiberglass body and wired it up while the chassis was in bare steel. The engine is a 2004 Corvette LS3 crate motor with 405 HP from the factory. It’s topped it with a Magnuson inter-cooled super charger that should bump it up into the 575 HP range. I'll post more engine pics later as there's some other unique mods to it.

    I wanted to make the chassis drivable and verify I had all tabs and brackets welded on before getting it powder coated. After that, I took the whole thing back apart and sent it out for sand blasting and powder coating. The bare chassis with aluminum suspension cradles installed weighs in at 460 pounds. My goal was high strength while also being light weight.



    Last edited by C5GTO; 05-20-2015 at 11:25 PM. Reason: fixing pic URL
    Joel Heinke
    Be original; don't be afraid of being bold!

  7. #7
    Senior Member C5GTO's Avatar
    Join Date
    May 2015
    Location
    Livermore, CA USA
    Posts
    218

    C5 GTO chassis build (cont.)








    The chassis bottom is clad with .050 3003 aluminum forming a smooth under belly. I used a bead roller to inset some portions and raise areas for riveting to the chassis tubes. In these pictures, the sheet still has poly on it. I plan to leave the bottom of the car in polished aluminum.



    Last edited by C5GTO; 05-20-2015 at 11:32 PM. Reason: fixing pic URL
    Joel Heinke
    Be original; don't be afraid of being bold!

  8. #8
    Senior Member
    Join Date
    Jun 2014
    Location
    Cape Town South Africa
    Posts
    188
    Hi Joel. For some reason i'm not seeing any of your pics. On your first posts as well. Cheers Jose'

  9. #9
    The OP may not have had permission to post photos at the time but they show up on my browser.

  10. #10
    ...................
    Last edited by infinitewill; 05-17-2015 at 09:06 AM. Reason: Double post

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •