P15 B Pillar cross section

[Eneto-55]

I'm wondering if any one here has chopped a 4-door P15, and happens to still have a piece of the B pillar laying around.  Don't get wired on me - I'm not thinking of chopping my car.  I would like to know if my rough drawing here accurately represents how the B Pillar is constructed.  I've done a rough drawing here (square corners), but the dimensions are pretty close, I think.  The piece drawn separately at the top is the piece that is covered by the upholstery-trim piece in the inside of the car.  It fits into the actual B pillar, and appears to be welded at fairly long intervals along the edges.  The offsets are where the tar-impregnated tack strips sit.  This inside piece has tabs at intervals along its length, which are bent over to hold the tack strips in place.

 

Here's my question or concern.  It appears to me that this inset piece is not overly secure inside the main part of the B pillar, and that if a shoulder belt is fastened to it, it would not withstand much force, and just be ripped out of the B pillar.  It is only intended to hold the upholstery trim and the wind-lacing in place.  I'm thinking that in order for a shoulder belt attachment point to really do any good, it needs to be fastened to the main part of the B pillar, not just to this filler strip.  What I'm considering is to make a U shaped piece which would fit inside the main channel of the B pillar, and then be secured in place with counter sink screws through the sides of the B pillar.  True, these screws would show when the doors were opened, but if that were a problem, it could also be plug welded, then that area cleaned up for repainting.  I would put in a channel that is around 7" long, because I plan to use the belt height adjusters out of the 93 Chrysler Town & Country I scrapped out.  The seat belt height adjustment mechanism would be bolted through the filler strip and into weld nuts on the inside of the added channel piece. (I am long in the torso, and so I need the shoulder belts considerably higher than my wife, or others in my family who might be driving or riding in the front seat.)  

 

Edited December 15, 2021 by Eneto-55
punctuation

[DJ194950]

You may want to get some ideas from thiscompany that has sold  aftermarket seat belts for older cars for years and is a solid company. There are how to install videos give some solid mounting inside of the pillars they have used that perhaps you can use?

 

See Address-

https://www.julianos.com/default.asp

 

DJ

[Eneto-55]

1 hour ago, DJ194950 said:

You may want to get some ideas from thiscompany that has sold  aftermarket seat belts for older cars for years and is a solid company. There are how to install videos give some solid mounting inside of the pillars they have used that perhaps you can use?

 

See Address-

https://www.julianos.com/default.asp

 

DJ

Thanks.  I went to the link, but my browser lists it as an unsafe (non https) site.  Went there anyway.  But that warning meant that the photos don't display. 

 

Most of the cars in the list are either 2 doors, or pickups.  The only one which might be helpful is the one for the 40 Ford.  It doesn't say whether it is a 2 or 4 door, but it talks about feeding the backing plate down through a hole in the top of the pillar, and that wouldn't be necessary if it were a 2 door.  (Anyway I suspect that on a 2 door P15 it would be a piece of cake to install shoulder belts.)  

 

But there isn't any large opening in the top of the B pillar on a P15 4 door, and the pillar is pretty narrow as well.  Also, the main issue in my mind is that the inner part of the B pillar is not sufficiently attached to the main structure of the pillar to withstand the strain that would be placed on it if there were a severe impact that was thrusting the person forward.  It might be even worse than not having a shoulder belt at all, because now you would have this ripped up piece of sheet metal from the inside of the pillar being flung past your neck.  (Not a pretty sight in my mind's eye.)  So I am assuming that I will need to cut out a section of that inside sheet metal, secure some more substantial plate inside the main structure of the B pillar, then weld (or screw) the cut out section back in.  (The original sheet metal would no longer be withstanding any of the force in an impact - it would just be there to support the wind lacing and the upholstery, all it was intended to do.)

 

I also have another question in relation to installing shoulder belts in a 4-door Special DeLuxe.  (The DeLuxe model doesn't have the cabin (interior) light switch there on the B pillar.)  It is right where I will need to be fastening the shoulder belt height adjuster, so it has to go someplace else.  I've been considering other locations, like in the C Pillar, or in the back of the front seat.  Both of these locations would put it in reach of only the back seat passengers.  But there is no switch on the right side at all, so it was perhaps intended for access by the driver, not the rear-seat passengers.  Or I suppose I could move it up higher on the left B pillar, but that would be pretty far up there (because of the size of the sliding height adjuster I plan to use).  My dash is out and all dismantled - isn't there a switch there for the driver to turn that rear light on & off - like to the left of the steering wheel?  (Or am I thinking of something else that's there?)  The Special DeLuxe also has a switch in the A pillar door jam for the right front door, so I guess they figured there was no need for an inside switch on that side.

[Andydodge]

I have a 1940 Oz Dodge 4dr sedan and installed lap/sash retractable front seat belts 40 yrs ago, the upper mount is via a narrow 3/16th thick plate about 5/8th wide x 2" long with the standard 7/16th UNF nut welded on the reverse, the thread was extended into the plate also..............the plate was dropped down from a hole in the upper pillar to a spot where I'd drilled a 7/16th hole, installed a 7/16th unf bolt to capture the plate against the inner pillar then used a pair of 3/16th pop rivets to attach the plate to the pillar.........the plate had its corners rounded and edges chamfered to negate the chance of "pull through" in an accident .............the lower pillar mount that has the retracting mechanism was actually installed on the floor with its mounting bolt thru the floor and secured with reinforcing plates on the bottom and again correct 7/16th seat belt bolts washer and plates used...........the centre mount which has the buckle was also mounted using correct 7/16th seat belt bolts,washers and reinforcement plates...........the rear seat has non retractable lap/sash belts at either side and a lap belt in the middle, all three belts mounted with correct 7/16th bolts,washers and plates ..............current style child safety seat mounts are also installed with the correct hardware on the rear parcel shelf............pics don't help much but I'm satisfied that my work is safe, strong and secure...........andyd  

Edited December 16, 2021 by Andydodge
more info

[Andydodge]

Eneto........my car has 3 interior lights......one at the top of each centre pillar and another larger version above the rear seat....all are connected to the same switch which lives on my drivers side centre pillar, actually under the seat belt webbing.........power is only connected to it when the headlight or parking lights are switched on, a wire connected to the stock headlight switch goes to the interior light switch.....thinking about this I vaguely remember using the holes for the small lights at the top of the pillar to feed the seat belt mount plates thru.........my cars centre pillar is much narrower than yours as shown in the pic, I do not think that even the most severe accident would pull a piece of the pillar away however it maybe worth cutting a pice from your pillar to allow you to fabricate a new inner strengthening piece & weld it in then reattach the inner pillar and fully seam weld it along both tack strip edges and fully top & bottom........also some sort of internal bracket plug welded to the outer pillar edge would also give further piece of mind.........as mentioned I'm happy with my setup but back then didn't see any need to take pics.............lol.............Andy Douglas