Thread: 35 Ford Roll Cage

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Want to install a roll cage in my 35 Ford 3 window. The car has a 4 link Chassis with independent front suspension, a narrowed 9 in with true trac rear, 13" disk brakes all around, 406 sbc with 577 flywheel HP (ran on a Stuska Dyno), car weighs 2400 lbs w/o driver and should run low 10's to high 9's. I really want to put a full cage in the car and am looking for advice on how to do it. How and where do I attach the bars to the frame? Given the location of the frame and the way the body with it's subrails mount to it, I am not sure how to do it.Do I weld gusseted mounting pads to the frame to locate the cage? Does anyone have advice or pictures on a late 30's Ford that you might have done? Thanks

first, check with the nhra rule book to make sure your car is legal. if the cage does not pass, you will be booted from the track. or atleast not be aloud to run your car. below is a link to a section of the nhra rule book with info on cages. i dont know if ihra tracks have different rules.

bob

www.nhraonline.com/contacts/tech_faq.html

The car is legal now until I run 11.49 or quicker and I think it is wise at this speed and most definitely at the car's ultimate capability to have a full cage for safety's sake. With the black interior and tinted windows the cage will almost be invisible.

Originally Posted by gypsy

The car is legal now until I run 11.49 or quicker and I think it is wise at this speed and most definitely at the car's ultimate capability to have a full cage for safety's sake. With the black interior and tinted windows the cage will almost be invisible.

It might "be legal now", but after you install a full cage you will be required to upgrade some other safety equipment (such as a window net) at the same time because they will inspect to a higher safety degree. I agree with the above suggestion, just follow the current NHRA book to the letter and you will be fine. Don't overlook installing a real race seat (like a Kirkey) at the same time as the cage.

Have fun.

Following the NHRA guidelines is not the problem, tying the cage to the framerails due to the fact that Ford placed them at the extreme outer edge of the body is. The frame to body design is not like that of a domestic car with a frame from the 60's, 70's, or 80's and the floor structure is not like a unibody car where plates can be welded to the floor.

If the car originally came as a framed car, all tubes must be welded to the frame or frame crossmember, NOT to the floor. Get a copy of the 2009 NHRA Rulebook and read General Regulations, Section 4:11, Roll Cage. Read it through thoroughly, then ask questions. I'm an SFI Silver Certified Tech Inspector, so I will be glad to smooth the way for you, but you should read the Rules first so that you know what I'm talking about. You can build the cage at home from mild steel fairly inexpensively by following the diagram shown as "FULL-BODIED CARS", 8.50 seconds and slower in Section 4:11. If you are not an expert welder though, plan to fit and tack the bars, then hire an expert with a mobile rig to come out and weld it up for you. That'll be the cheapest money you spend on the car, trust me on this. A mild steel cage can be migged or tigged. A chromoly cage can ONLY be tigged.
https://store.nhra.com/product.asp?0=230&1=267&3=180
Also read General Regulations, Sections 10:5 through 10:11.
There are many little nuances to installing a cage properly, so read up and get back to me. I went out to certify a chassis for a local racer a few years ago. If he had a nickel in the car, he had 50 thousand dollars in it. He was a novice welder and decided to weld it up himself. The welds were cold and looked like bird dookey. I had no choice but to tell him to rip it all out and start over. You cannot grind welds on a cage.

Old Chinese proverb::::

When building a cage, follow the tech guy's advice and when completed you'll have far fewer problems with the tech guys!!!!!!

Well, I think it was a proverb though maybe not Chinese.....

Is "dookey" a chinese word?

Originally Posted by Bob Parmenter

Is "dookey" a chinese word?

Not sure Bob, my Mom used it all the time in place of the other word.

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. 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.

"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.

Then you'll need crossmembers to attach the cages main mount points. All this is spelled out in the SFI specs, as mentioned...

Yup, first order of business should be to get the SFI book and read it cover to cover. Just google SFI Foundation.

That is what I was asking to begin with, I guess I just did not clarify very well what I was asking. I have the rule book and understand the concept of the cage, but this is my first attempt at putting a cage in a car without a structure under the floor to attach to or as in the case of my camaro, between the subframe connectors, additional plate welded to the floor, and the front down bars from the halo bar and the ones going through the firewall to the subframe, there was plenty of support to attach the cage to.

While the rule book does give some information & drawings the SFI book goes into much deeper detail in both written explanation & color coded drawings. It's well worth getting an SFI book. I would also contact the Chassis Tech in your area that will eventually be putting the sticker on your project. If you keep him in the loop he will answer specific questions as they arise. And, when the time comes to get it certified, you will have built it to his recommendations so there won't be any surprises.