Making a crossmember/brace for a Jaguar XK8 convertible

[Danez]

oreyt chaps
I've been asked to make a crossmember/ X brace for a mate of mine who has a Jaguar XK8 convertible. His old one had rotted away and the only one we can find online is over £300. So he's asked me to make one for him.
This is what it looks like (the X shaped bars under the front of the car, i presume to provide support with the roof missing)

My plan is to just use some flat bar 10mm thick and 25mm wide and weld a square plate where they meet in the middle.
Only problem is bending the metal bar sideways to achieve this angle as seen on the old crossmember below:

would it be possible for me to bend it on its side like that using heat, a bench vice and a hammer? or are there some better ways to achieve this? and do we reckon 10x25mm bar will be sufficiently strong? don't want to go too thick as it'll be a ballache to bend

cheers

 

[Redsailor]

That looks like heavy wall tubing that has been flattened, can you cut the old one and see what it's made from. A suitable alternative might be rhs (square box section) or just tube of suitable dimensions, much easier to bend as well.

From where it's situated I doubt it would do much to achieve longitudinal body rigidity , my guess is it just stiffens the front end???

 

[Danez]

That looks like heavy wall tubing that has been flattened, can you cut the old one and see what it's made from. A suitable alternative might be rhs (square box section) or just tube of suitable dimensions, much easier to bend as well.

From where it's situated I doubt it would do much to achieve longitudinal body rigidity , my guess is it just stiffens the front end???

rhs is a great shout!
this is what the old one looks like

 

[Morrisman]

I’d use separate pieces and butt weld all four bars together, at the correct angles, then weld the square doubler plate on after.
To be honest, that looks almost like some aftermarket suspension stiffener rather than a factory part.

 

[Danez]

I’d use separate pieces and butt weld all four bars together, at the correct angles, then weld the square doubler plate on after.
To be honest, that looks almost like some aftermarket suspension stiffener rather than a factory part.

did consider this....might even use a slightly larger plate to just to provide more surface to weld to

 

[MetalMonkey]

I wouldn’t make it out of solid. Hollow would be my choice as strong and not as heavy.
Either some oval or rectangular if height is an issue, or if there is the clearance probably tube would be best.
As above weld them onto the doubler plate no need to bend.

 

[RWD3M]

I wouldn’t make it out of solid. Hollow would be my choice as strong and not as heavy.
Either some oval or rectangular if height is an issue, or if there is the clearance probably tube would be best.
As above weld them onto the doubler plate no need to bend.

I'm with @MetalMonkey here, definitely go for tube, as close to OEM as poss. It won't only be in tension (which the solid bar will be fine for) but also an element of compression which the tube will handle better. Also, less likely to look like an add-on come MoT time

P.S. And yes, a bit of heat will help the bending.

 

[Danez]

I wouldn’t make it out of solid. Hollow would be my choice as strong and not as heavy.
Either some oval or rectangular if height is an issue, or if there is the clearance probably tube would be best.
As above weld them onto the doubler plate no need to bend.

I'm with @MetalMonkey here, definitely go for tube, as close to OEM as poss. It won't only be in tension (which the solid bar will be fine for) but also an element of compression which the tube will handle better. Also, less likely to look like an add-on come MoT time

P.S. And yes, a bit of heat will help the bending.

So after considering everything above....I'm thinking of going with some 20mm x 2.0mm tube: https://www.bmsteel.co.uk/20mm-od-x-2mm-round-erw-tube-6m/p4589
and not bothering to bend it just weld it at the correct angle on the square plate (or i could bend one and weld the other)
and for where it bolts into the chassis/floor I could heat up the ends and compress the tube using my press and then drill the holes/slot

edit: for reference the original brace is 25mm wide and 15mm thick

 

[addjunkie]

I’d use separate pieces and butt weld all four bars together, at the correct angles, then weld the square doubler plate on after.
To be honest, that looks almost like some aftermarket suspension stiffener rather than a factory part.

Tube for me too. You could use 4 pieces and flatten ends to weld to larger plate. But you can get oval tube, not sure of sizes specs though.

 

[Pigeon_Droppings2]

Toyota convertibles have similar setups...I think they add stiffness by preventing the fixed bolt points moving in the plane of the stiffener.

+1 for round as it'll look the part..also sod the bending!

I would probably use x4 pieces and then weld plates into the sides of the tubes...but I have a tendency to overcomplicate jobs!

 

[Danez]

Cheers for all the advice chaps! I'll let you know how I get on

 

[RWD3M]

Cheers for all the advice chaps! I'll let you know how I get on

I look forward to seeing the results

 

[RaceDiagnostics]

I’d use separate pieces and butt weld all four bars together, at the correct angles, then weld the square doubler plate on after.
To be honest, that looks almost like some aftermarket suspension stiffener rather than a factory part.

It is a factory part, there is one at the front and back of the convertibles to add a bit of rigidity.

 

[dobbslc]

There's one under my boys Mini convertible as well and that's as shonkly made as that one but made of box section instead.