Seat Belt In 31 Coupe

[lrjones]

I just started to figure out how to install retractable seat belts in my 31 Coupe and have hit a snag on where to attach the inboard belts. My original idea was to follow Vince Falters great write up in Ford Garage a few years ago. I was going to reinforce the body cross member right behind the tool pan and run the belts up through the seat riser frame. However, my seat is adjustable, which I like, and the belts from that attachment location would have to be routed rearward a little bit, then up and then forward between the backrest and the seat cushion. I don't think that would be good in that the belt wouldn't be pulling straight from the attachment point if in an accident. I would appreciate anyones advice on how to make this attachment. I tried moving the seat forward all the way but my knee and my belly hit the steering wheel. Thanks in advance for any help.

[KGBnut]

It has been a while since I did mine, but I seem to remember that between seat and the back portion of the frame is a curved piece of sheet metal. I cut slits in that sheet metal so that the seatbelts made a straight line the whole way. The tricky part was lining those slits so they wouldn't be sharp and cut through the belts. I ended up making up edging using windshield fluid hose.

Somewhere I know I have pictures of how I did it. I will have to look for them.

Ken

[lrjones]

Thanks Ken. Sure would appreciate seeing anything you have. I sent you a PM

[Kevin in NJ]

In my cabriolet I made square holes and used slit brake line to make the edges round.

Getting the seatbelt in a straight line is important. Any bends will cause slack when you hit something and you have almost no room for slack in the A.

It is also very important that the bolt and force be in shear when you attach to the sill. I ran a 1/2" metal bar under the rumble foot pan between the rear cross sill and the next forward sill. You might want to add some angle iron to distribute force at the forward cross member. Mine was wood so I had to do things a bit different.

[Jason in TX]

Sorry for the "hot rod" image... I own stock also... but this was a flathead swap into a Model A coupe.

But for the sake of discussion, I put a steel crossmember under my 1931 Coupe for the sole reason of bolting the inboard seat belts to it. I think this is honestly the safest way. But I think it is possible to do it other ways as well.

You could make a bolt in crossmember and bolt it with grade 8 bolts to the frame rails from under the car. it would also stiffen up the frame a little bit. They are very flexible.

[Marvin/TN]

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It isn't recommended that you bolt seat belts to the frame. Sometimes the body comes loose or at the least shifts in an accident which could cause serious injuries. I know for a fact bodies can and do shift. In 1958 I was hit head on by a garbage truck and the frame shifted back at least 2" on one side. If there would have been seat belts in a 1952 Ply, it would have made the belts a lot tighter and a Model A isn't nearly as strong as that Ply was. Seat Belts need to be anchored to the body not the frame. Do your research.

[Jason in TX]

Good points made on a body shifting off the frame. The floor in a 1952 plymouth is much more substantial than a Model A.

I have a wooden subframed cabriolet that has metal floor pans nailed to the wooden sub structure.

The NHRA rule book ( http://my5ltr.tripod.com/NHRArules.html ) Section 10.11 SEAT BELTS states that for a car with a fiberglass body ( I read this as the same as a weak floor of a Model A ) they state that

" In all cars with fiberglass floors, a crossmember of minimum 2-inch (5.1 cm) x 2-inch (5.1 cm) x .083-inch (2.1 mm) wall thickness square tubing must be installed between frame rails for proper driver's seat belt installation."

Ideally, building a strong subfloor behind the seat and back to the rear would be best, but that is modifying the body substantially.

I am sorry that you were hit head on by a garbage truck. I think that would have been much worse in a Model A.

[lrjones]

I was looking under my car quite a bit today. There is a cross member that goes across the floor of the body, right behind the tool pan, that is channel shaped, and there is another one behind that about 18" or so. I was wondering if I welded some 4" channel iron from one cross member to another cross member, in the center of the floor, and used that to attach the seat belt mounting bolts, if that would be adequate support. I would be able to get the attachment point further back in the rumble seat area to make the belt come through the seat at a better angle. That would mean that I wouldn't be attached to the frame in any way which I understand is a good thing. My car won't be judged anytime soon, so that is no concern. Opinions are welcome and appreciated.

[Tom Wesenberg]

In the 60's if I wanted to add seat belts to my car, the belts came with the mounting bolt and a large flat washer to keep the bolt from pulling through the floor. I'd think that would be plenty good for any Model A accident that you stand a chance of survival.

[Jason in TX]

I agree. Use a big wide piece of metal to act as a large "washer" under the floor to distribute the force to as much of the floor as possible.

[Barry B./ Ma.]

I put a 1/4"x 4" wide steel plate under the foot riser in the rumble seat body area that was the full length of the underbody on the 30 roadster I had, it was a simple installation and did the job.

[Marvin/TN]

I just didn't happen to drive my Model A that day. I still have the Model A but Ply long gone. It pulled some of the body mount bolts through the floor pan. My two brothers were in the Ply with me and neither of us got hurt, well minor injuries. I had a small cut on my chin that took 5 stitches, middle brother just got a few scratches on his fore head and youngest brother had no injuries, he was in the back seat. I am sure we were very lucky.

[Bruce of MN]

See reinforcement for my belts Also, Search function extends the Fordbarn benefits.