Chassis / Frame Design for the 1928 to 31 Model “A” Ford Street Rod – Part 5
Now it came time to work on what I thought was the most difficult part of the chassis, the front suspension. For the first attempt at this I decided to use exactly the same wheel base as the stock Model A Ford from 1928 to 1931. The front of the frame rails already had the same shape as the stock frame. The only difference was that my frame rails were made of 2” x 4” x 0.1” rectangular tubing. This would make a much more robust frame or chassis. You have to remember the original Model A Ford from 1928 to 1931 did not have much horsepower. I will be using a stock 1986 Corvette engine with over 200hp and over 200 ft-lbs of torque. This is a very important consideration in the hot rod frame or chassis design. The stock Model A Ford from 1928 to 1931 also had all of the cross members riveted to the side of “C” channel frame / chassis rails. Over 70 years these rivets loosen and the general strength of the frame / chassis will be compromised. The frame / chassis I will be designing will not used rivets or “C” channel side rails. All of the required cross members will be welded to the rectangle 2” x 4” x 0.1” rectangular side frame / chassis rails. Just pick up an original Model A Ford from 1928 to 1931 and watch it flex. The hot rod frame / chassis I am designing, using the C4 Corvette suspension components will not have the same flexing issues.
I needed to measure everything you could possibly imagine on the C4 Corvette front suspension cross member. The cross memeber comes out of the Corvette as a complete unit. In my case, it was removed from a 1986 Corvette Indy Pace car convertible. I am sure that the Corvette engineers never dreamed of seeing their cars put to this use. Corvette suspensions used in hot rods and custom cars.
The obvious starting point would be to measure the width of the C4 Corvette front cross member at the point where the upper control arms are attached. This measurement was slightly wider than the stock Model A Ford frame / chassis from 1928 to 1931 at the front wheel base center line. I thought that I would mount the controls arms in a similar fashion as the stock C4 Corvette did. It seemed reasonable to make brackets that would mount to the outside edge of the new frame or chassis rails. This meant making the frame slightly wider. In order to make sure this would not create a problem or look terrible when the body was mounted onto the frame, I widen the front frame and quickly lifted the body on to the frame. At that point I realize this would all work out perfectly.
Now I needed to establish the front ride height. Having the entire C4 Corvette front cross member dimensions in hand, it came time to mock up the front suspension. Using some 6” x 6” x 0.25” angle iron as temporary front cross member for the lower control arms was created. The width of the lower part of the cross member was matched to the inside mounting width of the lower control arms removed from the C4 Corvette. It was assembled using c-clamps and tack welded in place. A bracket was created for the upper control arms using angle iron. I clamped these brackets to the top the of the frame rails. Now it came time to mount the C4 Corvette front suspension parts onto the frame mock up and see how everything would like. Remember, humans are very visual, and since I am a professor, I realized that most of what we learn or process would be through our eyes. The brain tends to process the visual information much easier and faster. This is why I needed to mount the rims with tires to the suspension and have the body sitting on the frame. I would quickly see how everything would look. I even used an old Jaguar rear coil over shock to visualized possible mounting schemes for it.
The set up for the front suspension is all very temporary, and is only used to evaluate the ride height and overall look on the hot rod frame / chassis.
Come back next week to see how this progresses more towards the final product and finished state. Of course you can have an advanced look at the completed hot rod frame / chassis for my 1929 Ford Roadster. Just go the “PAGES” section new the top right of the screen and click on “Preview of the 1929 Ford Chassis with C4 Corvette suspension.
This frame / chassis will work for any Model A Ford from 1928 to 1931.