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Vintage Sprint Car


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The Madd Fabricator sells a vintage sprint car body the works well with either a Deruce frame or, for the talented, a tube frame.

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I hope to make a late 40s early 50s type sprint car to hold my Offy model.

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Digging through the scrap pile I came up with some initial other parts that will need reworking.

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Now to cut this beautiful body up so I can layout a frame.

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Then I found a slight Ooops. If I guide on the bottom pan to layout a frame there will be a tilt.

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Looks like MF used the upper panel line to establish the side panels. But if we tape things back together we can mark the off side panel using the floor as a guide, cut a panel piece and remake the off side. A little putty while final sanding will erase the old panel line.

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Then everything comes up roses and we can proceed to the frame.

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Have to leave the sprint for a short while though as I now have the remainder of the detail parts for the 427 TDR Roadster in the frosted material. Have to finish that up.

Space constrains me to one model at a time. Hate to leave it though as I also have some basic frame members in work here crying for finish work.

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  • 2 weeks later...

Got a little time to work on the chassis. Was just going to use a torque plate for the rear motor mount then I looked at all the room left over for things to fly back if something let loose up front and decided I better remake the rear motor mount to include a firewall. Still have to make dzus nut plates and smooth some things over.

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The bell housing is a bell housing/tranny for the Offy cast in resin by the Madd Fabricator. It can be used to mount an Offy in a Deuce or other car model besides the Sprinter. It even has a place for a starter. I hope to convert the tranny to look more like an In/Out gear box.

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  • 2 weeks later...

While I am working on a 1950s style tube frame for this body I will temporarily stick with the 1940s Ford frame idea just in case the tube frame runs into trouble. I am not a draftsman so everything is cut and try. Made a fire wall.

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Then reworked an old Deuce steering box to look more like a race car steering box. Also cut up that fine Offy/Transnission the Madd fabricator made for automobile use to also look more like a race car bell housing and In/Out box.

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Oh, this is going to be good!! Its great already!!

What scale is this? Based on the size of the tools showing in the pictures, it must be fairly big unless your tools are miniatures.

1/8th scale. Good place to use up all those old Deuce and T parts in the junk box.

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  • 2 weeks later...

I may have to get another body from The Madd Fabricator. I think I may move this time frame up to the 1960/70s from the original 1940 then 1950 concept. Right now I am in about 1950 with lever action shocks. For attachment purposes it would have been easier to use tube shocks from the Deuce kits. I thought about that then thought why not move into 1960 with TDR’s IFS and Quick Change rear end. Then the "Old Sprinter" told me the IFS never really worked for Sprint cars so maybe I will settle on the TDR coil over shocks to get rid of the Deuce kit suspension. I can also use their disk brake/wheel combinations too. Then you would not need a Deuce or T donor kit for suspension. If I am going to do that why not section the body for a lower profile. Maybe tilt the Offy over a bit or maybe one of TDR’s engines has a lower profile???? Maybe just switch to dry sump to reduce the pan depth??

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Syd, you're doing great, but if you decide to go with another body and have no use for that one, I would like to buy it from you and build a 50s sprinter. I use to watch them at Ascot , Culver City, Clovis and a few another places when I was a kid. Just an option if you would like. I make my own bodies but the Madd Fabricator is the master at it so it would be cool for me to make one of his racers. Tilting the motor with a dry sump will certainly give you a chance to get a lower profile ( and it will corner better LOL).

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Really struggling with these lever shock mounts. Clearly just using the tube shocks from a Deuce kit is the way to go if you plan to use the Deuce as a donor kit for suspension.

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I plan to build a follow up chassis with torsion bar suspension to see if that would not be actually easier or if that fails then TDR coil over shocks. Gotta be a way to build this w/o a Deuce as a donor kit.

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The radius rods are tacked in place. I did not add nerf bars to the back radius rods. I will save them for the 1960 version.

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Below is why I wanted to rebuild this model. I had made the belly pan too deep for the Deuce running gear because I originally thought I would be using the "T" frame for a 1940s version sprint car. That meant dropping some gussets to keep the radius rods about level. My problem is not being a draftsman everything is cut and try. As I studied Sprint Car history more and watched frames transform my concepts moved up in time. I hope by having the lower chassis member dropped some and using a torsion bar set up things will work out better. I wont be able to have the front bars placed before the axle which most of the reference pictures show because with this particular body the nose curve in too soon. Believe a torsion arm below and behind the front axle will work. Believe the rear can be a trailing torsion arm which seems to be popular.

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Guess I can't put off the seat any longer. I keep laying sub assemblies together to test the build plus seeing the combinations keeps me from giving up on this scratch build. It also gives me ideas on how to improve the chassis for the next generation. Using 8 gage wire for the chassis means I can do a lot of building cheaply. So far the body has been the only expense. Everything else is scrap or cast off parts. For instance the radiator was apparently bits and pieces from an old "T" build and it is too short. It needs to be taller for the final build and I think I remember where at least part of a Deuce radiator is stashed in my junk parts.

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Planning the 1960 model and being drawing challenged, I printed the side view of the model on two pieces of paper so I could try various frame layouts. This image is scaled to the 18-inch body if anyone wants to layout a tube frame concept for MF’s Vintage Sprint. I really haven’t the faintest idea of chassis flex or how much support the motor needs so any help would be appreciated. It will be a while before I really start the 1960 version as I should finish the 1950 version to see what other pitfalls await.

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The Offy pretty well fills the body height although it could maybe be 1/3” shorter. Thought I could section 1/3” out of the body middle but am afraid I would not be able to close the end pieces properly.

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This is how I might wind up. It looks boxy doesn’t it? Part of the layout is for support – part is trying to figure out where to cut panels. The frame member above the bottom holds the radius rod connection and the torsion bars at axle height. Maybe it could be the only frame bottom. Any suggestions from real sprint fans would be appreciated. I stopped following Sprint racing around 1950.

The torsion arm lengths seem to be about half or less a wheel diameter. The front torsion bars could then reside just in front of the motor if I move the existing motor location back about 1/3”. The front radius rod support would fit nicely in the frame triangle if that isn’t too long. Don’t know if there is a standard length for these things.

The wheelbase is 12” (96” at 1:1 scale) and as there is parallax in photography the dot/circles are about where the axles will really be. Not sure if I should use old Deuce kit shocks (pretty tall) or make shorter ones. Probably will wait to see how the frame actually lays out. When I drew this I thought the rear torsion bars could be under the seat (I forgot about the drive shaft then!) Guess they will have to be at the back of the frame and probably require a cut out at the bottom of the body. (See that’s why I need help from the real mechanics.)

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Laid out an initial panel concept. Again suggestions anyone? Will not really layout the panels until the frame is done but you can see how you might want to keep the panel layout in mind when designing the frame besides sub-assemblies and mechanics.

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OK! The Madd Fabricator delivered the new wheels yesterday. They are made up of tires and a three-piece wheel (inner rim. Center piece and outer rim). The three-piece wheel allows then to fit any tire size like the narrow front and wide rear shown. (Items pictured are as they came out of the mold – not cleaned or finish sanded)

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Now I can establish the axle height for sure and while I am at it place the Offy where it will finally go so that the frame can be laid out. (There will be room for the front torsion bars to reside in front of the motor.)

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The cockpit is roomy. I dropped a seat in to see how a driver might sit. The side padding will be almost 1/2”. Maybe the surround can be carved from wood. I have already tried and discarded it with foam board. Too hard to cut foam board accurately and no way to round edges. Making the padding meet the cockpit edge will be interesting also.

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Sure looking for fabrication suggestions or build help as I go along. How about some criticism or suggestions regarding frame design and material use like what could be used to simulate padding other than a wood carving?

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