Tech Week : 42-48 Bolt Bags Rear

By the end of September last year I bought a 46 Super deluxe Coupe, must confess I dont like the roof line on this coupes. But the price was right, since my quota of car was filled I involved my son. So this is a father and son project. One thing after repairing rust in the floor and so on, was to get it lower to the ground. Since it has a rear seat, airbags seamed like a good ide.

I have thought some time now how to make a bolt on bag setup for the 42-48 coupes.

I bought a couple of Firestone 9000 bags on Evilbay. And then the work begun.


In 1942 Ford got a rear panhard rod, this is a must since the bags cant handle forces from the side. We let the rear axle rest on the frame, later we will add rubber bumpers rasing it a bit and preventing the bags to compress to much.


Here is the 9000 bag it is connected at the top thru the angle connection, the bag has a minimum height of 115mm, Rideheight 230mm Maxheight 305mm (Sorry im a Metric man).



This is one hole on the side of the frame, that we opened up a bit and welded in a nut (M12).


We made two steelplates to mount the bag on, One upper and one lower. Then we mounted both plates with the distance of 15mm (Minimum size) Using a rod with some nuts. The upper one was bolted to the frame.



The lower Plate hangs from the original axle mount with long shackels, and a tube connected to the diff-house.


Made this bracket to bolt on to the diff, will probably drill some holes thrue the bolts and put in a wire so they don't unscrew.


Lower mount ready, the bag is mounted in the center hole. The bags is not allowed to rubb against anything at anytime.


Made an ear on the upperplate, and drilled a hole and put in a weldnut in the rear crossmember.


Since Henry did not think that the 46 Ford should ride so low, we had to move the panhard mount 15mm to the right to get the axle in the centre.



Testing with the bag's in drive position, later we will mount straps so the bag wont overextend. We will use the Original shocks to start with.


Had to put on a fender to check out the the look


Bags in Ride height position, looks good. Now we need to get some valves and stuff to get it ready for the road.

Ok ive added some pics of the underside of the lower mount.



The long tube is only keeping the mount to move sideways the majority of the force is taken up by the plate and the lower short tube that is connected to the shackel's. Also added a piece of tube for the bolt that mounts the bag, make mounting easier.


The "shackel" mount has some steel added to prevent forward/backward motion. One side is removable so the mount can be bolted of and on.

 

Some interesting engineering going on here. Neat project. Keep the pictures coming.

 

Why did you decide to go bolt-on? Is it so you can return to stock easily?

 

Actually it's that i need to get it thru the Swedish car inspection first, the more original the easier

And then it lends itself to bolt on in my book, and maybe i wont like the ride with bags.

 

What does the under side of the lower bag mount look like, that tube to the axle looks a little shakey to me.

 

Will the Swedish car inspection regulations permit you to run (what appear to be) copper brake tubing. Not allowed in our country!

 

A copper alloy called Kunifer is available in the UK being 90% copper and 10% nickel it is more resistant than copper to work hardening and does not cost very much more, and is obviously much more corrosion resistant than steel in our damp climate.

I have used both copper and kunifer on my daily drivers for the last 30 years without issue, I belive that (solid) brake lines should be firmly clipped in place with plastic or rubber insulated clips to prevent chafing and lessen vibration. If I remember correctly the recomended distance between clips is fairly short around 7 inches or so, again lessening the effect of vibration which causes the work hardening around the back of the flare.

 

same problem here.
I must build my car twice.
first for the dutch inspecion and then how I want it.

nice project

Jurgen

 

Copper brakeline was pretty popular in Europe for a while.

Some racing organisations even recomended that people replaced all steel lines for copper.

That was because a couple of racers had crashed their cars and it was found that steel lines with rust damage had caused it.

( they also wanted the lines to be wrapped with clear plastic hose to protect them from small impact damage, but I think they gave up on that after a while )

An added bonus was that the softer copper line made it easyer to make a flair that sealed.

I believe this was not the Cunifer line that you can buy right now.

It was redder in color, and softer.

And really thick walled.

 

That's what I'm thinking.

 

interesting build, keep posted

 

It's not allowed to run copper brakelines in Sweden either, this is a Copper coated steel tube.

 

Added a couple of pic's in my first post, at the top.

Im sure the mount is rigid/sturdy enough.

 

Do your inspections include weld inspections? If so I'd have to say you're going to fail.

Would you trust your son's life with those welds?



On this one you got like 70% of the weld on the top plate and 30% on the side.

I won't even get into the undercut and such on the rest of it. I don't mean to rip on you, if it was bodywork welding, I could care less, but this is stuff that takes you down the roads, roads you share with other people. It's a matter of safety. So please for your safety, your sons safety, and everyone who shares the roads with you's safety, please get a professional to re-do this.

 

No the don't in this case.

But I will take a look at it.

 

Hello,
I am a newbie here on the H.A.M.B but have been in the trade for twenty years, and in more than a couple of countries, as far as weld inspection goes I used to be a professional weld inspector and I share your concerns, the sad fact is many countries run a statuatory certification system where actual weld quality is not specified but rather comes under a separate "fit for purpose" heading where they simply state that "all welding must be fit for purpose" often judged by people with little or no welding experience, scary. Having said this, remarkably few vehicles fail just on weld quality, the failures usually are as a result of poor design, I would recommend that the "bar" that runs from the lower air bag mount to the diff centre be replaced with something that has a much greater resistance to bending like a nice fabricated "I" beam maybe with a drilled web, as the loads right next to the air bag mount will be pretty big, especially on a heavy bump probably exceeding the total weight of the car just on that round bar, even considering the fact that most of the load is taken on the shackle. otherwise I like the bolt on idea.
Best Regards
Rick