Thread: 35 Ford Roll Cage

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Thanks for the help and guidance

"The main frame rails on a Ford of this vintage run under the door sills and follow the perimeter of the body so there are no inboard frame rails to tie a cage to through the floor as on later year cars."

Most of us old guys on this board are very familiar with the frame configuration of this vintage of car. We all grew up hot rodding this old iron and I will submit to you that this is the perfect platform from which to build a cage. You want the A bar and B bar to be as close to the inside sheet metal as possible in order to have the driver "in the box". Use a hole saw to cut through the floor and weld the ends of the A and B bars to the frame. After all the cage is installed, fashion some C-shaped pieces of sheet metal to pop rivet or sheet metal screw to the floor of the car to fill in the space between the bars and the floor sheet metal. Same thing for the C bars, except they don't have to hug the interior sheet metal. They must be installed on the B bar no more than 5 inches from the top of the B bar, so you will want to weld them to the B bar at the top of the corner toward the center of the car. To make a really neat install, configure the bars and tack them in, then remove the body/frame bolts and raise the body a little. This will allow you to weld all the way around the A/halo and B/halo connections and B/C connections. If they aren't welded 360 on all connections, then two 2" x 2" gussets will be required on each connection, one on each side of the connection.

Another point I want to make about installing a cage. Get the B bar tacked in the car, then install the seat and position it in a comfortable driving position just as you would be racing the car. Then and only then should the crossbar be tacked in place between the B bar uprights. You want to tack it in at the top of your shoulders so that the shoulder belts will leave the crossbar and go directly over your shoulders, not uphill, not downhill as viewed from the side of the car. This will create the proper connection point for the rear connection of the side bar, so that it will pass your body between the shoulder and the elbow as it makes its way from the B bar to the bottom of the A bar/frame connection point.

"My question is, can I run 1-5/8 mild steel tubing from side to side, framerail to framerail, similar to a trans mount or shock mount, and then tie the cage to these "crossmembers"? I know that there is no way to attach the cage to the floor to support the cage as the stock floor does not have enough strength to support it but the problem arises from the fact that there is no part of the boxed perimeter frame under the car, it truly is a perimeter frame."

No, don't do this. You will put the tubing into a bending load. You seem to be riveted on attaching the cage inboard in the car. Get this out of your head. It's wrong, as I explained above about having the driver "in the box". It is the fact that it is a perimeter frame that makes it the perfect platform from which to start. I might even box the frame a few inches ahead of and behind the A, B and C bar connections to make it bulletproof.

Best way to make a lap belt/crotch strap install point is to weld a 1 1/4" diameter x 0.118" wall bar between the B bar uprights just above the floor. Put it in maybe an inch above the floor on the driver's side, straight across to the hump, then bend it up and over the hump to go to the other side of the B bar on the passenger side. Get 3 of these seat belt tabs and weld to this lower cross bar, one directly straight back from your left hip for the left side lap belt, one directly straight back from your right hip for the right side lap belt and one in the center for a crotch strap mount.
http://www.aa-mfg.com/pdshop/shop/item.aspx?itemid=622
Everybody installs the lap belts and crotch strap improperly. What I'm explaining here is a way for you to do them right. Bring the crotch strap under the seat and up to attach at the lap belt/shoulder belt connection. If you use stock OEM seat/seats, you can bring the crotch strap around the front of the seat to make the connection. If you use an aftermarket seat, YOU MUST bring the crotch strap up through the seat to make the connection, right under your....ahhhhh.....private parts. So, if you choose an aftermarket seat, make sure it has the slot in the seat to bring the crotch strap up through to make the connection.

You'll need a head rest installed no more than 4" from the back of your helmet with you in driving position. I have made them before by pirating a removeable head rest from the boneyard and making a bracket either hanging down from the bottom of the B bar or coming up off the top of the crossbar.

Thanks again for your help, this has explained it much better and I have ordered the SFI cage book.

Cool

I hope you post progress pics. as you build. I like watching other project as they go together.